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**EUROCAE/WG 49**

**Working Paper WG 49N14-14**

**07 June 2007**

**EUROCAE WG-49**

**Paris**

**11-13 June 2007**

**Review of differences between ED73 and do181 noted during February
2007 SC209/WG-49**

Prepared by Eurocontrol

Presented by Eric Potier

**[SUMMARY]{.underline}**

During common meeting held in February 2007 between SC209 and WG49
differences between DO181 and ED73 were reviewed.\
A number of these differences were not explained or resolved during the
meeting. This WP present the result of further investigation performed
on these differences.

The revised working paper shows those changes now included in ED-73,
shown in [GREEN]{.mark} in the RH column and actions required by SC-209
as [RED]{.mark} in LH column.

# General comments

+---+--------------+--------------+-----------------+-----------------+
| \ | Do-181       | ED-73        | Comment 140     | Proposal        |
| # |              |              |                 |                 |
+---+--------------+--------------+-----------------+-----------------+
| 1 |              |              |                 | Adopt a         |
| . |              |              |                 | consistent and  |
|   |              |              |                 | uniform         |
|   |              |              |                 | identification  |
|   |              |              |                 | of the optional |
|   |              |              |                 | requirements    |
|   |              |              |                 | and associated  |
|   |              |              |                 | tests.          |
+---+--------------+--------------+-----------------+-----------------+
| 2 |              |              |                 | After page 273  |
| . |              |              |                 | the page        |
|   |              |              |                 | restarts at     |
|   |              |              |                 | 259. Use        |
|   |              |              |                 | continuous page |
|   |              |              |                 | numbering       |
+---+--------------+--------------+-----------------+-----------------+
| 3 |              |              | Reply rate in   | Xpdr            |
| . |              |              | SSR 1200/s?     | manufacturers   |
|   |              |              |                 | agreed to test  |
|   |              |              |                 | their           |
|   |              |              |                 | transponders -- |
|   |              |              |                 | Need to update  |
|   |              |              |                 | ED , DO, ICAO   |
|   |              |              |                 | annex 10?       |
+---+--------------+--------------+-----------------+-----------------+
| 4 |              |              | Hijack mode to  |                 |
| . |              |              | be removed from |                 |
|   |              |              | ED?             |                 |
|   |              |              |                 |                 |
+---+--------------+--------------+-----------------+-----------------+
| 5 |              |              | Data-flash also | RTCA agreed to  |
| . |              |              | in DO?          | copy data-flash |
|   |              |              |                 | in DO           |
|   |              |              |                 |                 |
|   |              |              |                 | Check that      |
|   |              |              |                 | data-flash is   |
|   |              |              |                 | in line with    |
|   |              |              |                 | ICAO annex10    |
+---+--------------+--------------+-----------------+-----------------+
| 6 |              |              | ELS/EHS         |                 |
| . |              |              | testing:        |                 |
|   |              |              |                 |                 |
|   |              |              | -   Review      |                 |
|   |              |              |                 |                 |
|   |              |              |   specification |                 |
|   |              |              |     and check   |                 |
|   |              |              |     with RTCA   |                 |
|   |              |              |     proposal    |                 |
|   |              |              |                 |                 |
|   |              |              | -   Incorporate |                 |
|   |              |              |     it in ED73? |                 |
|   |              |              |                 |                 |
|   |              |              |     -   3.20    |                 |
|   |              |              |         Level 1 |                 |
|   |              |              |                 |                 |
|   |              |              |     -   3.21.   |                 |
|   |              |              |         Level 2 |                 |
|   |              |              |                 |                 |
|   |              |              |     -   3.22.   |                 |
|   |              |              |         Level 3 |                 |
|   |              |              |                 |                 |
|   |              |              |     -   3.23.   |                 |
|   |              |              |         Level 4 |                 |
|   |              |              |                 |                 |
|   |              |              |     -   3.24.   |                 |
|   |              |              |         Level 5 |                 |
|   |              |              |                 |                 |
|   |              |              |     -   3.25.   |                 |
|   |              |              |                 |                 |
|   |              |              |     Transponder |                 |
|   |              |              |                 |                 |
|   |              |              |      supporting |                 |
|   |              |              |         ACAS    |                 |
|   |              |              |                 |                 |
|   |              |              |     -   3.26 ES |                 |
|   |              |              |                 |                 |
|   |              |              |     -   3.27    |                 |
|   |              |              |         ELS     |                 |
|   |              |              |                 |                 |
|   |              |              |     -   3.28    |                 |
|   |              |              |         EHS     |                 |
|   |              |              |                 |                 |
|   |              |              | -   In fact ELS |                 |
|   |              |              |     is required |                 |
|   |              |              |     for         |                 |
|   |              |              |                 |                 |
|   |              |              |   international |                 |
|   |              |              |     traffic     |                 |
|   |              |              |                 |                 |
|   |              |              | -   Review      |                 |
|   |              |              |     generic     |                 |
|   |              |              |     procedure\  |                 |
|   |              |              |     be sure of  |                 |
|   |              |              |     correct     |                 |
|   |              |              |     testing of  |                 |
|   |              |              |     reg 10 bit  |                 |
|   |              |              |     25, 33, ... |                 |
|   |              |              |     MSSNV       |                 |
|   |              |              |                 |                 |
|   |              |              | -   Insert      |                 |
|   |              |              |     detailed    |                 |
|   |              |              |     RTCA        |                 |
|   |              |              |     procedure   |                 |
|   |              |              |     as an       |                 |
|   |              |              |     example     |                 |
|   |              |              |                 |                 |
|   |              |              | -   Check BDS   |                 |
|   |              |              |     40          |                 |
|   |              |              |                 |                 |
|   |              |              | -   Comm B      |                 |
|   |              |              |     broadcast   |                 |
|   |              |              |                 |                 |
|   |              |              | -               |                 |
|   |              |              |    Interleaving |                 |
|   |              |              |     space in AC |                 |
|   |              |              |     bits in Reg |                 |
|   |              |              |     40          |                 |
|   |              |              |                 |                 |
|   |              |              | -   Mode b      |                 |
+---+--------------+--------------+-----------------+-----------------+
| 7 |              |              | Invalid address | Honeywell       |
| . |              |              | at Start-up     | problem on some |
|   |              |              |                 | transponder     |
|   |              |              |                 | which continue  |
|   |              |              |                 | to reply in     |
|   |              |              |                 | Mode S          |
+---+--------------+--------------+-----------------+-----------------+
| 8 |              |              | Check           | AH action       |
| . |              |              | Environmental   |                 |
|   |              |              | test            |                 |
|   |              |              | (vibration,...) |                 |
+---+--------------+--------------+-----------------+-----------------+
| 9 |              |              | ICAO CW         |                 |
| . |              |              | interference to |                 |
|   |              |              | be added to     |                 |
|   |              |              | ED + DO         |                 |
+---+--------------+--------------+-----------------+-----------------+

#  Specific comments

## On the ground status and FS and VS fields

<table>
<colgroup>
<col style="width: 2%" />
<col style="width: 40%" />
<col style="width: 2%" />
<col style="width: 33%" />
<col style="width: 0%" />
<col style="width: 2%" />
<col style="width: 4%" />
<col style="width: 0%" />
<col style="width: 11%" />
<col style="width: 0%" />
</colgroup>
<thead>
<tr class="header">
<th>#</th>
<th>Do-181</th>
<th colspan="2">ED-73</th>
<th colspan="4">Comment</th>
<th colspan="2">Proposal</th>
</tr>
</thead>
<tbody>
<tr class="odd">
<td><ol type="1">
<li></li>
</ol></td>
<td><p>2.2.13.1.2 p 39 (Data handling and interface requirements)</p>
<p><strong>Variable Direct Data</strong></p>
<p>…</p>
<p>c. "On-the-Ground" Condition</p>
<p>The transponder <strong>shall</strong> report the automatically
determined on-the-ground state as determined by the aircraft in the
Flight Status (FS), Vertical Status (VS), and Capability (CA) fields
(see §2.2.14.4.14, §2.2.14.4.42, and §2.2.14.4.6), except when reporting
airborne status when on-the-ground is reported to the transponder under
the conditions specified in §2.2.18.2.7.</p>
<p><em><strong>Note:</strong> The on-the-ground state determined by the
aircraft does not include the effect of any TCS commands (see
§2.2.23.1.7).</em></p></td>
<td colspan="2"><p>3.17.1 p 43/44 (Data handling and interface
requirements)</p>
<p><strong>Direct Data</strong></p>
<p>…</p>
<blockquote>
<p>(3) "On the Ground" Condition</p>
</blockquote>
<p>The transponder shall report the automatically determined
on-the-ground state as determined by the aircraft in the Flight Status
(FS), Vertical Status (VS), and Capability (CA) fields except when
reporting airborne status when on-the-ground is reported to the
transponder under the conditions specified in subparagraph 3.20.2.7. (Ed
note: Check sub para No)</p>
<p><em><u>NOTE</u> : The on-the-ground state determined by the aircraft
does not include the effect of any TCS commands.</em></p></td>
<td colspan="3">Identical §.</td>
<td colspan="3"><mark>Corresponding sub-para of ED is
3.20.2.7.</mark></td>
</tr>
<tr class="even">
<td><ol start="2" type="1">
<li></li>
</ol></td>
<td><p>2.2.14.4.14 p 52 (Mode S requirements)</p>
<p><strong>FS Flight Status</strong></p>
<p>This 3-bit (6-8) downlink field reports the flight status of the
aircraft and is used in formats DF=4, 5, 20 and 21. Aircraft without the
means of automatically determining the on-the-ground condition
<strong>shall</strong> always report airborne state. The codes are:</p>
<table>
<colgroup>
<col style="width: 31%" />
<col style="width: 17%" />
<col style="width: 16%" />
<col style="width: 18%" />
<col style="width: 16%" />
</colgroup>
<tbody>
<tr class="odd">
<td>CODE</td>
<td>Alert</td>
<td>SPI</td>
<td>Airborne</td>
<td>On the Ground</td>
</tr>
<tr class="even">
<td>0</td>
<td>no</td>
<td>no</td>
<td>yes</td>
<td>no</td>
</tr>
<tr class="odd">
<td>1</td>
<td>no</td>
<td>no</td>
<td>no</td>
<td>yes</td>
</tr>
<tr class="even">
<td>2</td>
<td>yes</td>
<td>no</td>
<td>yes</td>
<td>no</td>
</tr>
<tr class="odd">
<td>3</td>
<td>yes</td>
<td>no</td>
<td>no</td>
<td>yes</td>
</tr>
<tr class="even">
<td>4</td>
<td>yes</td>
<td>yes</td>
<td colspan="2">Either</td>
</tr>
<tr class="odd">
<td>5</td>
<td>no</td>
<td>yes</td>
<td colspan="2">Either</td>
</tr>
<tr class="even">
<td colspan="5">6 is reserved and 7 is not assigned</td>
</tr>
</tbody>
</table></td>
<td colspan="2"><p>3.18.4.12 p 51 (Mode S requirements)</p>
<h4 id="flight-status-fs">Flight Status FS</h4>
<p>This 3-bit (6-8) downlink field reports the flight status of the
aircraft and is used in formats DF=4, 5, 20 and 21. The codes are:</p>
<table>
<colgroup>
<col style="width: 31%" />
<col style="width: 17%" />
<col style="width: 16%" />
<col style="width: 18%" />
<col style="width: 16%" />
</colgroup>
<tbody>
<tr class="odd">
<td>CODE</td>
<td>Alert</td>
<td>SPI</td>
<td>Airborne</td>
<td>On the Ground</td>
</tr>
<tr class="even">
<td>0</td>
<td>no</td>
<td>no</td>
<td>yes</td>
<td>no</td>
</tr>
<tr class="odd">
<td>1</td>
<td>no</td>
<td>no</td>
<td>no</td>
<td>yes</td>
</tr>
<tr class="even">
<td>2</td>
<td>yes</td>
<td>no</td>
<td>yes</td>
<td>no</td>
</tr>
<tr class="odd">
<td>3</td>
<td>yes</td>
<td>no</td>
<td>no</td>
<td>yes</td>
</tr>
<tr class="even">
<td>4</td>
<td>yes</td>
<td>yes</td>
<td colspan="2">Either</td>
</tr>
<tr class="odd">
<td>5</td>
<td>no</td>
<td>yes</td>
<td colspan="2">Either</td>
</tr>
<tr class="even">
<td colspan="5">6 and 7 are not assigned</td>
</tr>
</tbody>
</table></td>
<td colspan="3">Additional requirement in DO-181 and code 6 reserved
instead of not assigned</td>
<td colspan="3"><mark>Align ED-73</mark></td>
</tr>
<tr class="odd">
<td><ol start="3" type="1">
<li></li>
</ol></td>
<td><p>2.2.14.4.42 p 59</p>
<p><strong>VS Vertical Status</strong></p>
<p>This 1-bit (6) downlink field in DF=0, 16 indicates, when ZERO, that
the aircraft is airborne and, when ONE, that the aircraft is on the
ground. Aircraft without the means of automatically determining the
on-the-ground condition <strong>shall</strong> always report airborne
state.</p></td>
<td colspan="2"><p>3.18.4.38 p 56</p>
<h4 id="vertical-status-vs">Vertical Status VS</h4>
<p>This 1-bit (6) downlink field in DF=0, 16 indicates, when ZERO, that
the aircraft is airborne and, when ONE, that the aircraft is on the
ground.</p></td>
<td colspan="3">Additional requirement in DO-181</td>
<td colspan="3"><mark>Align ED-73</mark></td>
</tr>
<tr class="even">
<td><ol start="4" type="1">
<li><p><mark></mark></p></li>
</ol></td>
<td><p>2.2.18.2.7 p 71/72 (Level 1 requirements)</p>
<p><strong>Flight Status and Vertical Status Protocols (Figure
2-13)</strong></p>
<p>…</p>
<p><strong>c. Validation of declared on-the-ground status</strong></p>
<p><em><strong>Note 2:</strong> For aircraft with an automatic means of
determining vertical status, the CA field reports whether the aircraft
is airborne or on the ground. ACAS II acquires aircraft using the short
or Extended Squitter, both of which contain the CA field. If an aircraft
reports on-the-ground status, that aircraft will not be interrogated by
ACAS II in order to reduce unnecessary interrogation activity. If the
aircraft is equipped to report Extended Squitter messages, the function
that formats these messages may have information available to validate
that an aircraft reporting “on-the-ground” is actually
airborne.</em></p>
<p>Aircraft with an automatic means for determining the on-the-ground
condition <strong>shall</strong> perform the following validation
check:</p>
<p>If the automatically-determined air/ground status is not available or
is “airborne”, no validation <strong>shall</strong> be performed. If the
automatically-determined air/ground status is available and
“on-the-ground” condition is being reported, the air/ground status
<strong>shall</strong> be overridden and changed to “airborne” if either
ground speed data is available and is greater than 100 knots, or
airspeed date is available and is greater than 100 knots or if radio
altitude is available and is greater than 50 feet. DELETE TABLE</p>
<p><img src="media/image2.wmf"
style="width:3.71042in;height:1.64722in" /></p>
<p><em><strong>Note 3:</strong> While this test is only required for
aircraft that are equipped to format Extended Squitter messages, this
feature is desirable for all aircraft.</em></p></td>
<td colspan="2"><p>3.20.2.7 p 61 (level 1 requirements)</p>
<h4 id="flight-status-and-vertical-status-protocols-figure-3-12">Flight
Status and Vertical Status Protocols (Figure 3-12)</h4>
<p>Mode S-equipped aircraft shall report details of their flight status.
The source of and the rules for such reports are as follows:</p>
<blockquote>
<p>a. <u>Alert</u> - The transponder shall transmit the 4096
identification code in Mode A replies and in the ID field of downlink
format DF=5. This code can be changed by the pilot, and when a change is
made an alert condition shall be established. If the identification code
is changed to 7500, 7600 or 7700, the alert condition shall be
permanent. If the identification code is changed to any other value, the
alert condition shall be temporary and self-cancelling after 18 ±1.0
seconds (TC timer). The alert condition shall be reported in the FS
field. The permanent alert condition shall be terminated and replaced by
a temporary alert condition when the identification code is set to a
value other than 7500, 7600 or 7700.</p>
<p>b. On-the-Ground Report – The on-the-ground status of the aircraft
<strong>shall</strong> be reported in the FS field and the VS field and
the CA field. If a means for automatically indicating the on-the-ground
condition (<em>e.g.,</em> a weight on wheels or strut switch) is
available at the transponder data interface, it <strong>shall</strong>
be used as the basis for the reporting of status (FS, VS, for CA codes 4
or 5 for airborne or on-the ground). If a means for automatically
indicating the on-the-ground condition is not available at the
transponder data interface, the FS and VS codes <strong>shall</strong>
indicate that the aircraft is airborne and the CA field
<strong>shall</strong> indicate that the aircraft is either airborne or
on the ground (CA=6).</p>
<p>c. <u>Special Position Identification</u> - When manually selected,
the transponder shall transmit the equivalent of the SPI in the FS field
of surveillance replies DF=4,5. This code shall be transmitted for
18 ±1.0 seconds (TI timer) after initiation and can be reinitiated at
any time.</p>
</blockquote></td>
<td colspan="3">Requirements related to the validation of the
on-the-ground status are missing in ED.</td>
<td colspan="3"><p><del>WG49 will insert this paragraph in level 2
section.</del> Put on hold until further discussion at next meeting
(Table is an issue and also location of requirement in level 1 xpdr</p>
<p>RTCA SC209 to consider to move this requirement in level 2
section</p></td>
</tr>
<tr class="odd">
<td><ol start="5" type="1">
<li></li>
</ol></td>
<td><p>2.2.23.3.7 p 132 (ES level requirements)</p>
<p><strong>Airborne/Surface State Determination</strong></p>
<p>Aircraft with an automatic means of determining on-the-ground
condition <strong>shall</strong> use this input to select whether to
report the airborne or surface message types. Aircraft without such
means <strong>shall</strong> report the airborne type messages.</p></td>
<td colspan="2"><p>3.21.2.6.5 p 86/87 (ES level requirements</p>
<h5 id="airbornesurface-state-determination">Airborne/Surface State
Determination</h5>
<p>Aircraft with an automatic means of determining on-the-ground
condition shall use this input to select whether to report the airborne
or surface message types. Aircraft without such means shall report the
airborne type messages. <mark>Aircraft with or without such automatic
on-the-ground determination shall use position message types as
commanded by control codes in the TCS subfield (Paragraph 3.21.2.6.7).
After timeout of the TCS commands, control of airborne/surface
determination shall revert to the means described above.</mark></p>
<p><mark><strong>NOTE:</strong> Extended squitter ground stations
determine aircraft airborne or surface status by monitoring aircraft
position, altitude and ground speed. Aircraft determined to be on the
ground that are not reporting the surface position message type will be
commanded to report the surface format via the TCS subfield. The normal
return to the airborne position message type is via a ground command to
report the airborne message type. To guard against loss of
communications after takeoff, commands to report the surface position
message type automatically timeout.</mark></p></td>
<td colspan="3"></td>
<td colspan="3"><p>The on the ground validation is already covered in
level 2 transponder in both documents .</p>
<p>SC209 to consider to add the highlighted paragraph (no action as text
is included in section 2.2.23.1.5.2</p></td>
</tr>
<tr class="even">
<td><ol start="6" type="1">
<li></li>
</ol></td>
<td><p>2.4.2.12.2 p 176 (test procedure)</p>
<p><strong>Variable Direct Data (§2.2.13.1.2)</strong></p>
<p>Step 5 Flight Status and Vertical Status (§2.2.13.1.2.c)</p>
<p>Interrogate with UF=0 and UF=16 and verify that the VS field is a ONE
when the "on-the-ground port" of the transponder is set to the
on-the-ground condition.</p>
<p>Also, verify that the VS field is a ZERO otherwise.</p>
<p>Interrogate with formats UF=4, 5, 20, 21 and verify that the
transponder follows the protocol of §2.2.14.4.14, and Figure
2-13.</p></td>
<td colspan="2"><p>5.4.12.2 p 186 (test procedure)</p>
<p><strong>Variable Direct Data (§2.2.13.1.2)</strong></p>
<blockquote>
<p>e. <u>STEP 5 - Flight Status and Vertical Status</u></p>
</blockquote>
<p>Interrogate with UF=0 and UF=16 and record that the VS field is a ONE
when the "on-the-ground" port of the transponder is set to the
"on-the-ground" condition, and a ZERO otherwise.</p>
<blockquote>
<p>Interrogate with formats UF=4, 5, 20, 21 and record that the above
indications are correctly contained in the FS field <mark>(3.18.4.12 and
figure 3.12)</mark> and <mark>that CA is set to 4 (airborne) or
5.(ground), if a status is provided to the transponder, and code CA=6
(either airborne or on-the-ground) is reported when the input is idle
(or not available).</mark></p>
</blockquote></td>
<td colspan="3"></td>
<td colspan="3"><p><mark>Wg-49 to add text highlighted in
blue.</mark></p>
<p>SC209 to check reference to figure 2-13. (RHS confirmed it is the
right figure but the figures are not numbered in order)</p>
<p>SC209 to consider to add text highlighted in yellow to cover CA
field. (SC209 action to followup on this)</p></td>
</tr>
<tr class="odd">
<td><ol start="7" type="1">
<li></li>
</ol></td>
<td colspan="2"><p>2.5.4.7 p 203</p>
<p><strong>Procedure #7 FS and VS Protocol/Code Tests</strong></p>
<p>Required Code Verification Test</p>
<p>Observe that the FS code follows the transponder states as specified
in §2.2.14.4.14 and verify that VS=1, if and only if the "on-the-ground"
input is active.</p>
<p><em><strong>Note:</strong> The Alert Register is set when the manual
or interface input to the ID function is</em></p>
<p><em>7500, 7600, 7700.</em></p>
<p><em>The TC timer is started when the input to the ID function is
changed.</em></p>
<p><em>The TI timer is started when manual or interface input exists for
SPI momentarily.</em></p>
<p><em>The Ground Register is set when input to the "on-the-ground"
interface indicates that condition.</em></p>
<p><img src="media/image3.wmf"
style="width:4.65278in;height:2.75278in" /></p></td>
<td colspan="3"><p>5.5.8.7 p 207</p>
<h4 id="procedure-7-fs-and-vs-protocolcode-tests">Procedure #7 FS and VS
Protocol/Code Tests</h4>
<p>…</p>
<p>5.5.8.7.2 Required Code Verification Test</p>
<p>Observe that the FS code follows the transponder states as specified
in paragraph 3.18.4.12 and verify that VS=1, if and only if the
"on-the-ground" input is active.</p>
<p>In particular, the following shall be verified :</p>
<blockquote>
<p>a. when the input of the ID function is changed to 7500, 7600, 7700
verify that:</p>
<p>(1) the alert register is permanently set,</p>
<p>(2) the FS field value is 2, 3, or 4,</p>
<p>(3) T<span class="smallcaps">C</span> is not started</p>
<p>(4) verify that the FS field value changes to a value not equal to 2,
3, or 4 only when a new input of the ID function other than 7500, 7600,
7700 is made.</p>
<p>b. when the input of the ID function is changed to other values than
7500, 7600, 7700 verify that:</p>
<p>(1) the alert register is set,</p>
<p>(2) the FS field value is 2, 3, or 4,</p>
<p>(3) TC is started,</p>
<p><mark>(3)</mark> following TC expiry, verify that the FS field value
is not 2, 3, nor 4.</p>
<p>c. when manual or interface input exists for SPI, verify that :</p>
<p>(1) TI timer is started,</p>
<p>(2) the FS field value is 4 or 5,</p>
<p>(3) following TI expiry, verify that the FS field value is neither 4
nor 5.</p>
</blockquote></td>
<td colspan="2"></td>
<td><p><mark>Replace (3) by (4) in ED.</mark></p>
<p>NO difference between DO181 and ED73</p></td>
<td></td>
</tr>
<tr class="even">
<td><ol start="8" type="1">
<li></li>
</ol></td>
<td><p>2.5.4.7 p 204</p>
<p><strong>Procedure #7 FS and VS Protocol/Code Tests</strong></p>
<p>On-the-Ground Validation Test</p>
<p>For transponders that support automatic on-the-ground condition input
and either implement Extended Squitter formatting or support the
on-the-ground validation requirements of §2.2.18.2.7.c, the following
test <strong>shall</strong> be performed.</p>
<p>The on-the-ground input is used in determining the codes for FS, VS
and CA fields. The requirements of Section §2.2.18.2.7.c utilize radio
altitude, ground speed and airspeed inputs to validate the on-the-ground
status when indicated by the input to the transponder.</p>
<p>If the conditions for overriding the on-the-ground status indicated
by the input to the transponder, the airborne status
<strong>shall</strong> be utilized to select FS, VS and CA field
coding.</p>
<p>Also, for extender squitter format selection, airborne formats
<strong>shall</strong> be transmitted unless overridden by ground
station interrogation commands. CA field validation for Acquisition
squitters and Extended Squitters is verified as part of Procedure #6 in
§2.5.4.6, so the following test can be incorporated as part of that
testing.</p>
<p>Setup the transponder to indicate on-the-ground status by input to
the transponder. With no input of radio altitude, airspeed and ground
speed to the transponder, verify that the FS codes are determined by the
transponder states above with the Ground Register set to on-the-ground
and VS is set to 1. Input radio altitude, airspeed and ground speed to
the transponder. Since not all aircraft installations may have access to
all three inputs, testing is required for all combinations of inputs
being provided to the transponder so that each input is tested
individually and collectively. This is to insure that any one input
reporting a value that sets airborne status as specified in
§2.2.18.2.7.c, properly outputs FS values according to Figure 2-13 with
the Ground Register reset to NOT indicate on-the-ground condition and VS
is ZERO. If all inputs are supported by the transponder, a total of 27
combinations are required. This represents 9 cases with radio altitude
not input, 9 cases with a value above 50 feet and 9 cases with a value
below or equal to 50 feet. The same variation for airspeed and ground
speed is required except the values selected would be above 100 knots to
satisfy the requirement to reset the Ground Register to NOT indicate
on-the-ground condition and a value at 100 knots or below to not modify
the on-the ground status.</p></td>
<td colspan="3"><p>5.5.8.7 p 205/206</p>
<h4 id="procedure-7-fs-and-vs-protocolcode-tests-1">Procedure #7 FS and
VS Protocol/Code Tests</h4>
<h5 id="section">…</h5></td>
<td colspan="2"></td>
<td colspan="3"><p>Test procedure step for On-the-ground validation is
not present in ED. (subject to further discussion as per S4)</p>
<p>Text in line with DO181 text to be added.</p>
<p>SC209 to consider revision of DO181 text in particular the second
paragraph starting by if conditions…</p></td>
</tr>
<tr class="odd">
<td><ol start="9" type="1">
<li></li>
</ol></td>
<td colspan="4"><p>It is proposed to include a a further step in test
procedure #4 in ED and DO to address the replying of the transponder to
All-Call interrogations depending on the same conditions as the On-the
ground status.</p>
<p>Set the Air-Ground discrete input to no input (as when there is no
automatic detection on board the aircraft), interrogate the transponder
with Mode S All-Call and verify it is not replying.</p>
<p>Set the Air-Ground discrete input to Ground, interrogate the
transponder with Mode S All-Call and verify it is not replying.</p>
<p>Set the Air-Ground discrete input to Airborne, interrogate the
transponder with Mode S All-Call and verify it is replying.</p>
<p>Set the Air-Ground discrete input to Ground/No input, simulate the 27
conditions as described above and check that when the on-the-ground
status is not overridden the transponder does not reply to All-Call
interrogations and that it does reply when the on-the-ground status is
overridden as airborne.</p>
<p>A similar test procedure step shall be defined in test procedure #6
in ED and DO to check that ES capable transponder transmit airborne or
surface message type according to the overridden or not on the ground
status.</p></td>
<td colspan="2"></td>
<td colspan="3"><p>EP to prepare the test procedures</p>
<p>EP to propose something to WG49</p>
<p>SC209 to look into this perhaps including a note</p></td>
</tr>
<tr class="even">
<td><ol start="10" type="1">
<li></li>
</ol></td>
<td><p>3.3.14 p 256 (Installation tests)</p>
<p><strong>On-the-Ground Condition</strong></p>
<p>Verify that the equipment correctly reports the “on-the-ground”
condition. If it is feasible to simulate the airborne condition, verify
that the equipment correctly reports an “airborne” condition.</p>
<p>Also verify that when the unit is in the “inhibit replies” condition
(see §2.1.7.b), the transponder continues to generated Mode S squitters
and replies to discretely-addressed Mode S interrogations (UF=0, 4, 5,
16, 20, 21, 24), but does not reply to ATCRBS, ATCRBS/Mode S All-Call or
Mode S-Only All-Call interrogations. If the unit is not in the “inhibit
replies” condition verify that the transponder continues to generate
Mode S squitters and to reply to ATCRBS, ATCRBS/Mode S All-C all or Mode
S-Only All-Call and discretely-addressed Mode S interrogations (UF=0, 4,
5, 16, 20, 21, 24).</p></td>
<td colspan="3"><p>6.2.13 p 276 (Installation tests)</p>
<h3 id="validation-of-declared-on-the-ground-status">Validation of
declared on-the-ground status</h3>
<p><mark>Note.- While this is only a requirement for aircraft that are
equipped with extended squitter functionality, this feature is desirable
for all aircraft.</mark></p>
<p>Aircraft with an automatic means for determining the on-the-ground
condition that are equipped to format <mark>extended squitter</mark>
messages shall perform the following validation check:</p>
<p>If the automatically determined air/ground status is not available or
is “airborne”, no validation shall be performed. If the automatically
determined air/ground status is available and “on-the-ground” condition
is being reported, the air/ground status shall be overridden and changed
to “airborne” if the conditions given for the vehicle category in the
table below are satisfied,</p>
<table>
<colgroup>
<col style="width: 27%" />
<col style="width: 20%" />
<col style="width: 6%" />
<col style="width: 17%" />
<col style="width: 6%" />
<col style="width: 20%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="6">Determination of airborne status</td>
</tr>
<tr class="even">
<td>A/V category</td>
<td>Ground Speed</td>
<td></td>
<td>Airspeed</td>
<td></td>
<td>Radio Altitude</td>
</tr>
<tr class="odd">
<td>No information</td>
<td colspan="5">No change to on-the-ground status</td>
</tr>
<tr class="even">
<td>Weight &lt; 15 500 lbs (7 031 kg)</td>
<td colspan="5">No change to on-the-ground status</td>
</tr>
<tr class="odd">
<td>Weight &gt; or = 15 500 lbs (7 031 kg)</td>
<td>&gt;100 knots</td>
<td>or</td>
<td>&gt;100 knots</td>
<td>or</td>
<td>&gt;50 feet</td>
</tr>
<tr class="even">
<td>High Performance (&gt;5g acceleration and 400 knots)</td>
<td>&gt;100 knots</td>
<td>or</td>
<td>&gt;100 knots</td>
<td>or</td>
<td>&gt;50 feet</td>
</tr>
<tr class="odd">
<td>Rotorcraft</td>
<td colspan="5">No change to on-the-ground status</td>
</tr>
</tbody>
</table></td>
<td colspan="2"></td>
<td colspan="3"><p>Blue paragraph to be modified to be consistent with
requirement on all level2 transponder.</p>
<p>EP to combine text from DO181 with text from ED73. table in
2.2.18.2.7</p>
<p>(WG49 to discuss at further meeting)</p></td>
</tr>
</tbody>
</table>

##  CA field

+---+-------------------------+---------------------------+---+---+--------+
| \ | Do-181                  | ED-73                     |   | C | Pr     |
| # |                         |                           |   | o | oposal |
|   |                         |                           |   | m |        |
|   |                         |                           |   | m |        |
|   |                         |                           |   | e |        |
|   |                         |                           |   | n |        |
|   |                         |                           |   | t |        |
+===+=========================+===========================+===+===+========+
| 1 | 2.2.14.4.6 note p 49/50 | 3.18.4.5 Note p 49/50     |   |   | [Text  |
| 1 |                         |                           |   |   | in     |
| . | **CA Transponder        | ####                      |   |   | yellow |
|   | Capability**            | Transponder Capability CA |   |   | in DO  |
|   |                         |                           |   |   | shall  |
|   | This 3-bit (6-8)        | This 3-bit (6-8) downlink |   |   | be     |
|   | downlink field is used  | field reports transponder |   |   | added  |
|   | in [DF=11, the All-Call | capability and is used in |   |   | to     |
|   | reply and acquisition   | [DF=11]{.mark}, the       |   |   | ED.]{  |
|   | squitter, and in DF=17, | All‑Call reply. The codes |   |   | .mark} |
|   | the Extended            | are:                      |   |   |        |
|   | Squitte]{.mark}r. The   |                           |   |   | (the   |
|   | codes are:              |                           |   |   | table  |
|   |                         | ---- --- ---------------- |   |   | needs  |
|   |   -                     |   0    =   signifies no   |   |   | f      |
|   | -- --- ---------------- |            communications |   |   | urther |
|   |   0   =   signifies no  |            capability     |   |   | c      |
|   |                         |            (surveillance  |   |   | hanges |
|   |          communications |            only), no      |   |   | to be  |
|   |           capability    |            ability to set |   |   | a      |
|   |           (surveillance |            CA code 7,     |   |   | ligned |
|   |           only), no     |            either on the  |   |   | with   |
|   |                         |            ground or      |   |   | SARPS) |
|   |          ability to set |            airborne       |   |   |        |
|   |           CA code 7,    |                           |   |   |        |
|   |           either on the |   1    =   Reserved       |   |   |        |
|   |           ground or     |                           |   |   |        |
|   |           airborne      |   2    =   Reserved       |   |   |        |
|   |                         |                           |   |   |        |
|   |   1   =   Reserved      |   3    =   Reserved       |   |   |        |
|   |                         |                           |   |   |        |
|   |   2   =   Reserved      |   4    =   signifies at   |   |   |        |
|   |                         |                           |   |   |        |
|   |   3   =   Reserved      |          least Comm‑A and |   |   |        |
|   |                         |            Comm‑B         |   |   |        |
|   |   4   =   signifies at  |            capability,    |   |   |        |
|   |                         |            ability to set |   |   |        |
|   |        least Comm‑A and |            CA code 7, on  |   |   |        |
|   |           Comm‑B        |            the ground     |   |   |        |
|   |           capability,   |                           |   |   |        |
|   |                         |   5    =   signifies at   |   |   |        |
|   |          ability to set |                           |   |   |        |
|   |           CA code 7, on |          least Comm‑A and |   |   |        |
|   |           the ground    |            Comm‑B         |   |   |        |
|   |                         |            capability,    |   |   |        |
|   |   5   =   signifies at  |            ability to set |   |   |        |
|   |                         |            CA code 7,     |   |   |        |
|   |        least Comm‑A and |            airborne       |   |   |        |
|   |           Comm‑B        |                           |   |   |        |
|   |           capability,   |   6    =   signifies at   |   |   |        |
|   |                         |                           |   |   |        |
|   |          ability to set |          least Comm‑A and |   |   |        |
|   |           CA code 7,    |            Comm‑B         |   |   |        |
|   |           airborne      |            capability,    |   |   |        |
|   |                         |            ability to set |   |   |        |
|   |   6   =   signifies at  |            CA code 7,     |   |   |        |
|   |                         |            either on the  |   |   |        |
|   |        least Comm‑A and |            ground or      |   |   |        |
|   |           Comm‑B        |            airborne       |   |   |        |
|   |           capability,   |                           |   |   |        |
|   |                         |                           |   |   |        |
|   |          ability to set |  7    =   signifies DR is |   |   |        |
|   |           CA code 7,    |                           |   |   |        |
|   |           either on the |          ≠ to zero, or FS |   |   |        |
|   |           ground or     |                           |   |   |        |
|   |           airborne      |           equals 2,3,4,5, |   |   |        |
|   |                         |            either on the  |   |   |        |
|   |                         |            ground or      |   |   |        |
|   | 7   =   signifies DR is |            airborne (see  |   |   |        |
|   |                         |            paragraphs     |   |   |        |
|   |        ≠ to zero, or FS |            3.18.4.10,     |   |   |        |
|   |                         |            3.18.4.12      |   |   |        |
|   |         equals 2,3,4,5, |            and3.18.4.37). |   |   |        |
|   |           either on the |                           |   |   |        |
|   |           ground or     | ---- --- ---------------- |   |   |        |
|   |                         |                           |   |   |        |
|   |         airborne (see § | When the conditions for   |   |   |        |
|   |           2.2.14.4.8 &  | CA code 7 are not         |   |   |        |
|   |           2.2.14.4.9).  | satisfied, installations  |   |   |        |
|   |   -                     | that have communications  |   |   |        |
|   | -- --- ---------------- | capability but do not     |   |   |        |
|   |                         | have automatic means to   |   |   |        |
|   | When the conditions for | set on‑the‑ground         |   |   |        |
|   | CA code 7 are not       | conditions shall use CA   |   |   |        |
|   | satisfied,              | code 6. Aircraft with     |   |   |        |
|   | installations that have | automatic on‑the‑ground   |   |   |        |
|   | communications          | determination shall use   |   |   |        |
|   | capability but do not   | CA codes 4 and 5. Data    |   |   |        |
|   | have automatic means to | link capability reports   |   |   |        |
|   | set on-the-ground       | (paragraph 3.21.1.12 d)   |   |   |        |
|   | conditions **shall**    | shall be available for CA |   |   |        |
|   | use CA code 6. Aircraft | codes 4, 5, 6 and 7.      |   |   |        |
|   | with automatic          |                           |   |   |        |
|   | on-the-ground           | **NOTE:** CA codes 1 to 3 |   |   |        |
|   | determination **shall** | were used by earlier Mode |   |   |        |
|   | use CA codes 4 and 5.   | S transponders that did   |   |   |        |
|   | Data link capability    | not use CA code 7.        |   |   |        |
|   | reports (see            |                           |   |   |        |
|   | §2.2.19.1.12.5)         |                           |   |   |        |
|   | **shall** be available  |                           |   |   |        |
|   | for CA codes 4, 5, 6    |                           |   |   |        |
|   | and 7.                  |                           |   |   |        |
|   |                         |                           |   |   |        |
|   | ***Note:** CA codes 1   |                           |   |   |        |
|   | to 3 were used by       |                           |   |   |        |
|   | earlier Mode S          |                           |   |   |        |
|   | transponders that did   |                           |   |   |        |
|   | not use CA code 7.      |                           |   |   |        |
|   | [Transponders with      |                           |   |   |        |
|   | these codes provide a   |                           |   |   |        |
|   | data link capability    |                           |   |   |        |
|   | report (see             |                           |   |   |        |
|   | §2.2.19.1.12.5). No     |                           |   |   |        |
|   | data link transactions  |                           |   |   |        |
|   | other than GICB         |                           |   |   |        |
|   | extraction including    |                           |   |   |        |
|   | aircraft identity, TCAS |                           |   |   |        |
|   | RA extraction, and      |                           |   |   |        |
|   | downlink broadcast      |                           |   |   |        |
|   | extraction, should be   |                           |   |   |        |
|   | attempted with these    |                           |   |   |        |
|   | transponders.]{.mark}*  |                           |   |   |        |
+---+-------------------------+---------------------------+---+---+--------+
| 1 | 2.2.19.1.7 p 80         | #### 3.21.1.7 p 66        |   |   | [In ED |
| 2 |                         |                           |   |   | the    |
| . | **Capability Report**   | #### Capability Report    |   |   | ref    |
|   |                         |                           |   |   | erence |
|   | The transponder         | The transponder shall     |   |   | shall  |
|   | **shall** reply with a  | reply with a non-zero     |   |   | be to  |
|   | non-zero value of CA    | value of CA (paragraph    |   |   | item e |
|   | (see §2.2.14.4.6) in    | 3.18.4.5) in the          |   |   | i      |
|   | the capability field of | capability field of       |   |   | nstead |
|   | DF=11 and DF=17,        | DF=11, indicating that    |   |   | of     |
|   | indicating that further | further data link         |   |   | d.]{   |
|   | data link information   | information is available  |   |   | .mark} |
|   | is available in a data  | in a data link capability |   |   |        |
|   | link capability report  | report (paragraph         |   |   |        |
|   | (§2.2.19.1.12.5         | 3.21.1.12 [d]{.mark}).    |   |   |        |
+---+-------------------------+---------------------------+---+---+--------+

##  Mode S Reply rate capability

+---+------------------------+-----------------------+------+-----------+
| \ | Do-181                 | ED-73                 | Com  | Proposal  |
| # |                        |                       | ment |           |
+===+========================+=======================+======+===========+
| 1 | 2.2.3.4.2 p 21         | #### 3.4.2 p 29       |      | ~~SC209   |
| 3 |                        |                       |      | to        |
| . | **Mode S Reply Rate    | ### Reply Rat         |      | consider  |
|   | Capability**           | e Capability - Mode S |      | DO shall  |
|   |                        |                       |      | specify   |
|   | a\. A transponder      | [The total reply rate |      | that the  |
|   | equipped for only      | over each time        |      | Mode S    |
|   | short Mode S downlink  | interval specified    |      | reply     |
|   | formats (DF),          | below, shall be the   |      | rate      |
|   | **shall** have the     | sum of the individual |      | shall be  |
|   | following minimum      | Mode A/C replies at   |      | in        |
|   | reply rate             | an average rate of    |      | addition  |
|   | capabilities:          | 500 per               |      | to the    |
|   |                        | second]{.mark} and    |      | ATCRBS    |
|   | 50 Mode S replies in   | the Mode S reply rate |      | reply     |
|   | any 1-second interval. | over that interval.   |      | rate of   |
|   |                        |                       |      | 500       |
|   | 18 Mode S replies in a | > a\. Short DF Reply  |      | replies   |
|   | 100-millisecond        | > Rates               |      | per       |
|   | interval.              |                       |      | second.~~ |
|   |                        | A transponder         |      |           |
|   | 8 Mode S replies in a  | equipped for only     |      | [ED shall |
|   | 25-millisecond         | short Mode S Downlink |      | specify   |
|   | interval.              | Formats (DF), shall   |      | that the  |
|   |                        | have the following    |      | Mode S    |
|   | 4 Mode S replies in a  | minimum reply rate    |      | reply     |
|   | l.6-millisecond        | capabilities.         |      | rate      |
|   | interval.              |                       |      | shall be  |
|   |                        | > \(1\) 50 Mode S     |      | in        |
|   | b\. A transponder      | > replies in any      |      | addition  |
|   | equipped for long Mode | > one‑second          |      | to any    |
|   | S reply formats        | > interval;           |      | squitter  |
|   | **shall** be able to   | >                     |      | tran      |
|   | transmit as long       | > \(2\) 18 Mode S     |      | smissions |
|   | replies:               | > replies in a        |      | that the  |
|   |                        | > 100‑millisecond     |      | tr        |
|   | At least 16 of the 50  | > interval;           |      | ansponder |
|   | Mode S replies in any  | >                     |      | is        |
|   | 1-second interval.     | > \(3\) 8 Mode S      |      | required  |
|   |                        | > replies in a        |      | to        |
|   | At least 6 of the 18   | > 25‑millisecond      |      | make      |
|   | Mode S replies in a    | > interval;           |      | .]{.mark} |
|   | 100-millisecond        | >                     |      |           |
|   | interval.              | > \(4\) 4 Mode S      |      | [ED shall |
|   |                        | > replies in a        |      | include a |
|   | At least 4 of the 8    | > 1.6‑millisecond     |      | similar   |
|   | Mode S replies in a    | > interval.           |      | note as   |
|   | 25-millisecond         | >                     |      | DO making |
|   | interval.              | > b\. Long DF Reply   |      | reference |
|   |                        | > Rates               |      | to §      |
|   | At least 2 of the 4    |                       |      | 3.23.b    |
|   | Mode S replies in a    | A transponder         |      | .]{.mark} |
|   | l.6-millisecond        | equipped for long     |      |           |
|   | interval.              | Mode S reply formats  |      | ED to be  |
|   |                        | shall be able to      |      | modified  |
|   | [c. A transponder      | transmit as long      |      | with the  |
|   | equipped with the      | replies,              |      | yellow    |
|   | enhanced data link     |                       |      | text.     |
|   | protocols (see         | > \(1\) at least 16   |      |           |
|   | §2.2.21) **shall** be  | > of the 50 Mode S    |      | See       |
|   | able to transmit as    | > replies in any      |      | W         |
|   | long replies:]{.mark}  | > one‑second          |      | G49N11-06 |
|   |                        | > interval;           |      |           |
|   | [At least 24 of the 50 | >                     |      | The green |
|   | Mode S replies in any  | > \(2\) at least 6 of |      | test is   |
|   | 1-second               | > the 18 Mode S       |      | already   |
|   | interval.]{.mark}      | > replies in a        |      | covered   |
|   |                        | > 100‑millisecond     |      | in DO181  |
|   | [At least 9 of 18 Mode | > interval;           |      | section   |
|   | S replies in a         | >                     |      | 2.2.3.4 & |
|   | 100-millisecond        | > \(3\) at least 4 of |      | 2.2.3.4.1 |
|   | interval.]{.mark}      | > the 8 Mode S        |      |           |
|   |                        | > replies in a        |      | ACAS      |
|   | [At least 6 of 8 Mode  | > 25‑millisecond      |      | para. ref |
|   | S replies in a 25      | > interval;           |      | added     |
|   | millisecond            | >                     |      | 3.27 b    |
|   | interval.]{.mark}      | > \(4\) at least 2 of |      |           |
|   |                        | > the 4 Mode S        |      |           |
|   | [At least 2 of 4 Mode  | > replies in a        |      |           |
|   | S replies in a 1.6     | > 1.6‑millisecond     |      |           |
|   | millisecond            | > interval.           |      |           |
|   | interval.]{.mark}      |                       |      |           |
|   |                        |                       |      |           |
|   | All of the above reply |                       |      |           |
|   | rates **shall** be in  |                       |      |           |
|   | addition to any        |                       |      |           |
|   | squitter transmissions |                       |      |           |
|   | that the transponder   |                       |      |           |
|   | is required to make.   |                       |      |           |
|   |                        |                       |      |           |
|   | *[**Note:** Higher     |                       |      |           |
|   | reply rates are        |                       |      |           |
|   | required by a          |                       |      |           |
|   | TCAS-compatible        |                       |      |           |
|   | transponder            |                       |      |           |
|   | (see]{.mark}*          |                       |      |           |
|   |                        |                       |      |           |
|   | *                      |                       |      |           |
|   | [§2.2.22.b.).]{.mark}* |                       |      |           |
+---+------------------------+-----------------------+------+-----------+

##  RF peak power

+---+------------------------+-----------------------+------+-----------+
| \ | Do-181                 | ED-73                 | Com  | Proposal  |
| # |                        |                       | ment |           |
+===+========================+=======================+======+===========+
| 1 | 2.3.2.2.2 p 139        |                       | ED   | It is     |
| 4 |                        |                       | does | proposed  |
| . | **RF Peak Power Output |                       | not  | to remove |
|   | (§2.2.3.2)**           |                       | desc | the       |
|   |                        |                       | ribe | assumed   |
|   | Step 1 ATCRBS Power    |                       | spec | d         |
|   | Output (§2.2.3.2)      |                       | ific | uplicated |
|   |                        |                       | pr   | procedure |
|   | Connect the equipment  |                       | oced | and to    |
|   | as shown in Figure     |                       | ures | make      |
|   | 2-26. Set the          |                       | for  | reference |
|   | transponder for a      |                       | e    | in the DO |
|   | 14-pulse (7777) reply. |                       | nvir | document  |
|   | Interrogate the        |                       | onme | to the    |
|   | transponder with a     |                       | ntal | procedure |
|   | standard Mode A        |                       | tes  | described |
|   | interrogation at 1200  |                       | ting | in §      |
|   | interrogations per     |                       | and  | 2.4.2.2.2 |
|   | second or the maximum  |                       | only | and move  |
|   | for which the          |                       | m    | figure    |
|   | transponder is         |                       | akes | 2-26 in   |
|   | designed and measure   |                       | r    | this      |
|   | the single pulse       |                       | efer | section.  |
|   | having the least RF    |                       | ence |           |
|   | power output.          |                       | to   | [To be    |
|   | Determine that the     |                       | the  | discussed |
|   | power output meets the |                       | stan | under     |
|   | requirements of        |                       | dard | general   |
|   | §2.2.3.2.              |                       | p    | d         |
|   |                        |                       | roce | iscussion |
|   | ![](m                  |                       | dure | on        |
|   | edia/image4.wmf){width |                       | and  | envi      |
|   | ="3.973611111111111in" |                       | d    | ronmental |
|   | height="               |                       | escr | test      |
|   | 1.4305555555555556in"} |                       | ibes | procedur  |
|   |                        |                       | the  | e]{.mark} |
|   | **Figure 2-26:**       |                       | r    |           |
|   |                        |                       | ange |           |
|   | Step 2 Mode S Power    |                       | of   |           |
|   | Output (§2.2.3.2)      |                       | e    |           |
|   |                        |                       | nvir |           |
|   | Repeat Step 1 with a   |                       | onme |           |
|   | standard Mode A        |                       | ntal |           |
|   | ATCRBS/Mode S All-Call |                       | co   |           |
|   | interrogation at the   |                       | ndit |           |
|   | standard rate.         |                       | ions |           |
|   |                        |                       | to   |           |
|   |                        |                       | be   |           |
|   |                        |                       | tes  |           |
|   |                        |                       | ted. |           |
+---+------------------------+-----------------------+------+-----------+
| 1 | 2.4.2.2.2 p 156/157    | 5.4.2.2.2 p 147       |      | 1^st^     |
| 5 |                        |                       |      | item      |
| . | **RF Peak Power Output | ##### Test Procedure  |      |           |
|   | (§2.2.3.2)**           |                       |      | do        |
|   |                        | Connect the equipment |      | nothing,  |
|   | Equipment Required:    | as shown in           |      | record    |
|   |                        | [Fig                  |      | means     |
|   | ATC Test Set with P4   | ure 5‑3]{.underline}. |      | record    |
|   | capability (TIC        |                       |      | and check |
|   | T-50-3A/4B, or         | > a\. [STEP 1 -       |      | against   |
|   | equivalent).           | > Mode A/C Power      |      | re        |
|   |                        | > Output]{.underline} |      | quirement |
|   | Wide Band Dual Channel | > (Paragraph 3.3.3)   |      |           |
|   | Oscilloscope (HP       |                       |      | 2^nd^     |
|   | 1710B, or equivalent). | Set the transponder   |      | item      |
|   |                        | for a 14 pulse reply  |      |           |
|   | Measurement Procedure: | (Mode-A code 7777).   |      | WG49 to   |
|   |                        |                       |      | rewrite   |
|   | Step l ATCRBS Power    | Interrogate the       |      | text for  |
|   | Output (§2.2.3.2)      | transponder with a    |      | long Mode |
|   |                        | Mode A interrogation  |      | S reply   |
|   | Connect the equipment  | and record the peak   |      | and       |
|   | as shown in Figure     | power level of the    |      | specify   |
|   | 2-26.                  | single reply pulse    |      | long Mode |
|   |                        | having the least RF   |      | S         |
|   | Set the transponder    | power level.          |      | inte      |
|   | for a 14 (7777) pulse  |                       |      | rrogation |
|   | reply. Interrogate the | > While varying the   |      | rate in   |
|   | transponder with a     | > interrogation rate  |      | both ED   |
|   | standard Mode A        | > from 100            |      | and DO to |
|   | interrogation and      | > interrogations per  |      | be 16 per |
|   | measure the single     | > second to the       |      | second    |
|   | pulse having the least | > maximum             |      | for       |
|   | RF power output. While | > interrogation rate  |      | level2    |
|   | varying the            | > specified for the   |      | tr        |
|   | interrogation rate     | > transponder,        |      | ansponder |
|   | from 100               | > [record the         |      | and       |
|   | interrogations per     | > variation in peak   |      | adding    |
|   | second to the maximum  | > power level of the  |      | the       |
|   | interrogation rate     | > single reply pulse  |      | tra       |
|   | specified for the      | > having the least RF |      | nsmission |
|   | transponder,           | > power               |      | of 6      |
|   | [determine that the    | > level]{.mark}.      |      | extended  |
|   | power output meets the | >                     |      | squitter  |
|   | requirements of        | > Repeat the          |      | for the   |
|   | §2.2.3.2]{.mark}.      | > procedure,          |      | tr        |
|   |                        | > recording the level |      | ansponder |
|   | Repeat the procedure   | > and variation in    |      | that are  |
|   | measuring the single   | > peak power level of |      | ES        |
|   | pulse having the most  | > the single reply    |      | capable + |
|   | RF power output.       | > pulse having the    |      | TCAS      |
|   |                        | > highest RF power    |      |           |
|   | Step 2 Mode S Power    | > level.              |      | Refer     |
|   | Output (§2.2.3.2)      | >                     |      | W         |
|   |                        | > b\. [STEP 2 -       |      | G49N11-05 |
|   | Repeat Step l with a   | > Mode S Power        |      | RF Peak   |
|   | standard Mode A        | > Output]{.underline} |      | Power     |
|   | ATCRBS/Mode S All-Call | > (Paragraph 3.3.3)   |      | Output    |
|   | interrogation at       | >                     |      | 5.4.2.2.2 |
|   | standard rate only.    | > Repeat              |      |           |
|   |                        | >                     |      | Update in |
|   | [-]{.mark}             |  [STEP 1]{.underline} |      | a         |
|   |                        | > with a              |      | ccordance |
|   |                        | > Mode A/Mode S       |      | with      |
|   |                        | > All-Call            |      | WG49N05a  |
|   |                        | > interrogation at    |      |           |
|   |                        | > standard rate only. |      | SC209 to  |
|   |                        |                       |      | consider  |
|   |                        | [For transponders     |      | inclusion |
|   |                        | with long reply       |      | of ED     |
|   |                        | capability, repeat    |      | text in   |
|   |                        | [STEP 1]{.underline}  |      | DO in the |
|   |                        | with a Mode S         |      | 2.4       |
|   |                        | interrogation, using  |      | chapter   |
|   |                        | any format and coding |      | and       |
|   |                        | for which a long      |      | 2.3.2.2.2 |
|   |                        | reply is              |      | chapter   |
|   |                        | required]{.mark}.     |      |           |
+---+------------------------+-----------------------+------+-----------+

##  RR field

+---+------------------------+--------------------+----+---------------+
| \ | Do-181                 | ED-73              | C  | Proposal      |
| # |                        |                    | om |               |
|   |                        |                    | me |               |
|   |                        |                    | nt |               |
+===+========================+====================+====+===============+
| 1 | 2.2.14.4.35 p 58       | 3.18.4.32 p 55     | RR | [Extend the   |
| 6 |                        |                    | 2  | table as      |
| . | **RR Reply Request**   | ###                | 0- | fo            |
|   |                        | # Reply Request RR | 31 | llows]{.mark} |
|   | This 5-bit (9-13)      |                    | to | in both DO    |
|   | uplink field contains  | This 5-bit (9-13)  | c  | [and ED to    |
|   | length and content of  | uplink field       | la | take into     |
|   | the reply requested by | contains length    | ri | account BDS   |
|   | the interrogators. RR  | and content of the | fy | 40, 50 and 60 |
|   | is part of the         | reply requested by | (  | for           |
|   | surveillance and       | the interrogators. | 20 | ELS.]{.mark}  |
|   | Comm-A interrogations  | RR is part of the  | -4 |               |
|   | UF=4, 5, 20, 21.       | surveillance and   | 0) |               |
|   |                        | Comm-A             |    | ------------- |
|   | The codes are outlined | interrogations     | In | --- --------- |
|   | below:                 | UF=4, 5, 20, 21.   | No | ------ ------ |
|   |                        | The codes are      | te | ------------- |
|   | ![](me                 | outlined below:    | 1  |   RR C        |
|   | dia/image5.wmf){width= |                    | of | ode           |
|   | "3.7104166666666667in" |   ------- ------   | ED | Reply Length  |
|   | height="               | -- --------------- | DI |    MB Content |
|   | 1.6888888888888889in"} |   RR Code R        | =  |               |
|   |                        | eply    MB Content | 3  |   0-15        |
|   | ***Note:** If the      |                    | h  |          Shor |
|   | first bit of the RR    |          Length    | as | t           N |
|   | code is ONE, the last  |                    | be | ot applicable |
|   | four bits of the 5-bit |   0-15    Short    | en |               |
|   | RR code, if            |     Not applicable | f  |   16          |
|   | transformed into their |                    | or |           Lon |
|   | decimal equivalent,    |   16      Long     | go | g             |
|   | designate the number   |      Air-Initiated | tt | Air-Initiated |
|   | (BDS1) of the          |                    | en |               |
|   | requested source. BDS2 |             Comm-B | w  |               |
|   | is assumed to be ZERO  |                    | he |          Comm |
|   | [if not specified by   |      (3.21.1.12 b) | re | -B (3.21.1.12 |
|   | DI=3 or 7 and          |                    | as |               |
|   | RRS.]{.mark}*          |   17      Lo       | §  |               |
|   |                        | ng     \"Data Link | 3. |            b) |
|   |                        |                    | 21 |               |
|   |                        |         Capability | .2 |   17          |
|   |                        |                    | .1 |             L |
|   |                        |           Report\" | .( | ong           |
|   |                        |                    | 6) |   \"Data Link |
|   |                        |      (3.21.1.12 e) | m  |               |
|   |                        |                    | ak |               |
|   |                        |   18               | es |               |
|   |                        | Long     Flight ID | r  |        Capabi |
|   |                        |                    | ef | lity Report\" |
|   |                        |        (3.21.1.13) | er |               |
|   |                        |                    | en |               |
|   |                        |   19      Long     | ce |               |
|   |                        |    ACAS Resolution | to | (3.21.1.12 e) |
|   |                        |                    | §  |               |
|   |                        |    Advisory Report | 3  |   18          |
|   |                        |                    | .1 |               |
|   |                        |         (3.23.3.4) | 8. |  Long         |
|   |                        |                    | 4. |     Flight ID |
|   |                        |   20-31   Lon      | 32 |               |
|   |                        | g     Not assigned |    |               |
|   |                        |   ------- ------   |    |               |
|   |                        | -- --------------- |    |   (3.21.1.13) |
|   |                        |                    |    |               |
|   |                        | **NOTE 1:** If the |    |   19          |
|   |                        | first bit of the   |    |         Long  |
|   |                        | RR code is ONE,    |    |            AC |
|   |                        | the last four bits |    | AS Resolution |
|   |                        | of the 5-bit RR    |    |               |
|   |                        | code, if           |    |               |
|   |                        | transformed into   |    |            Ad |
|   |                        | their decimal      |    | visory Report |
|   |                        | equivalent,        |    |               |
|   |                        | designate the      |    |               |
|   |                        | number (BDS1) of   |    |               |
|   |                        | the requested      |    |    (3.23.3.4) |
|   |                        | source. BDS2 is    |    |               |
|   |                        | assumed to be ZERO |    |               |
|   |                        | [if not specified  |    |  [20]{.mark}  |
|   |                        | by DI=7 and        |    |      [Long]{. |
|   |                        | RRS]{.mark}. See   |    | mark}   [Sele |
|   |                        | paragraph 3.21.2.1 |    | cted vertical |
|   |                        | a(4).              |    |               |
|   |                        |                    |    |               |
|   |                        | [**NOTE 2:** Codes |    |          inte |
|   |                        | 20-31 are reserved |    | ntion]{.mark} |
|   |                        | for applications   |    |               |
|   |                        | such as data link  |    |   [21]{.mar   |
|   |                        | communications,    |    | k}      [Long |
|   |                        | ACAS, etc.]{.mark} |    | ]{.mark}   [T |
|   |                        |                    |    | rack and turn |
|   |                        |                    |    |               |
|   |                        |                    |    |               |
|   |                        |                    |    |             r |
|   |                        |                    |    | eport]{.mark} |
|   |                        |                    |    |               |
|   |                        |                    |    |               |
|   |                        |                    |    |  [22]{.mark}  |
|   |                        |                    |    |      [Long]{. |
|   |                        |                    |    | mark}   [Head |
|   |                        |                    |    | ing and speed |
|   |                        |                    |    |               |
|   |                        |                    |    |               |
|   |                        |                    |    |             r |
|   |                        |                    |    | eport]{.mark} |
|   |                        |                    |    |               |
|   |                        |                    |    |   [23]{.mark} |
|   |                        |                    |    |       [Long]{ |
|   |                        |                    |    | .mark}   [Res |
|   |                        |                    |    | erved]{.mark} |
|   |                        |                    |    |               |
|   |                        |                    |    |   [24-31]{.ma |
|   |                        |                    |    | rk}   [Long]{ |
|   |                        |                    |    | .mark}   [Not |
|   |                        |                    |    |               |
|   |                        |                    |    |               |
|   |                        |                    |    |           ass |
|   |                        |                    |    | igned]{.mark} |
|   |                        |                    |    |               |
|   |                        |                    |    | ------------- |
|   |                        |                    |    | --- --------- |
|   |                        |                    |    | ------ ------ |
|   |                        |                    |    | ------------- |
|   |                        |                    |    |               |
|   |                        |                    |    | Sc209 to      |
|   |                        |                    |    | considerate   |
|   |                        |                    |    | it together   |
|   |                        |                    |    | with SC209    |
|   |                        |                    |    | WP01-08R1     |
|   |                        |                    |    |               |
|   |                        |                    |    | [Add          |
|   |                        |                    |    | reference to  |
|   |                        |                    |    | the sections  |
|   |                        |                    |    | describing    |
|   |                        |                    |    | registers 40  |
|   |                        |                    |    | 50 60]{.mark} |
|   |                        |                    |    | (DO181        |
|   |                        |                    |    | references    |
|   |                        |                    |    | are Table     |
|   |                        |                    |    | B-3-64, -80 & |
|   |                        |                    |    | -96)          |
|   |                        |                    |    |               |
|   |                        |                    |    | [Remove Note  |
|   |                        |                    |    | 2             |
|   |                        |                    |    | subsequ       |
|   |                        |                    |    | ently]{.mark} |
|   |                        |                    |    |               |
|   |                        |                    |    | [In ED        |
|   |                        |                    |    | include DI =  |
|   |                        |                    |    | 3 in Note     |
|   |                        |                    |    | 1.]{.mark}    |
+---+------------------------+--------------------+----+---------------+

##  Interrogation standard repetition rate

+---+------------------------+-----------------------+------+-----------+
| \ | Do-181                 | ED-73                 | Com  | Proposal  |
| # |                        |                       | ment |           |
+===+========================+=======================+======+===========+
| 1 | 2.4.1.h.1 p 152        | 5.2.1 p 142           | D    | [Align ED |
| 7 |                        |                       | iffe | on DO and |
| . | \(f\) [Interrogation   | > f\. [Interrogation  | rent | include   |
|   | Repetition Standard    | > Repetition          | w    | standar   |
|   | Rate]{.mark}: Unless   | > Rate]{.mark}        | ordi | d]{.mark} |
|   | otherwise noted in the | >                     | ngs. |           |
|   | measurement procedure, | > Unless otherwise    |      |           |
|   | interrogation rates    | > noted in the Test   |      |           |
|   | **shall** be 450 ±25   | > Procedure,          |      |           |
|   | Hz for ATCRBS          | > interrogation rates |      |           |
|   | interrogations and 45  | > shall be 450 ±25 Hz |      |           |
|   | ±5 Hz for All-Call and | > for Mode A/C        |      |           |
|   | Mode S interrogation.  | > interrogations and  |      |           |
|   |                        | > 45 ±5 Hz for        |      |           |
|   |                        | > All‑Call and Mode S |      |           |
|   |                        | > interrogation.      |      |           |
+---+------------------------+-----------------------+------+-----------+

##  Mode S replies: Pulse shape and spectrum

+---+------------------------+-----------------------+------+-----------+
| \ | Do-181                 | ED-73                 | Com  | Proposal  |
| # |                        |                       | ment |           |
+===+========================+=======================+======+===========+
| 1 | 2.2.4.2.3 p 24         | 3.3.2 p 25            | [    | [Add =    |
| 8 |                        |                       | ]{.m | sign for  |
| . | **Mode S Reply Pulse   | ### Trans             | ark} | all low   |
|   | Shape**                | mitter Reply Spectrum |      | limits in |
|   |                        |                       |      | both ED   |
|   | a\. The pulse          | The spectrum of the   |      | (78MHz    |
|   | amplitude variation    | transponder           |      | )]{.mark} |
|   | between one pulse and  | transmitter output    |      | and DO    |
|   | any other pulse in a   | shall not exceed the  |      |           |
|   | reply **shall** not    | limits shown in       |      | SC209 to  |
|   | exceed 2 dB.           | [Table                |      | consider  |
|   |                        | 3.1]{.underline} and  |      | this      |
|   | b\. The pulse rise     | [Figure               |      | addition  |
|   | time **shall not**     | 3.1]{.underline}.     |      |           |
|   | exceed 0.1             |                       |      |           |
|   | microsecond.           |   ---------           |      |           |
|   |                        | --------- ----------- |      |           |
|   | c\. The pulse decay    |   Frequ               |      |           |
|   | time **shall not**     | ency          Maximum |      |           |
|   | exceed 0.2             |   Differe             |      |           |
|   | microsecond.           | nce\        Relative\ |      |           |
|   |                        |   from C              |      |           |
|   | d\. The spectrum of a  | arrier (MHz) Response |      |           |
|   | reply **shall not**    |                       |      |           |
|   | exceed the following   |             from Peak |      |           |
|   | bounds:                |                       |      |           |
|   |                        |   [\>                 |      |           |
|   | ![](m                  | ]{.underline}   -3 dB |      |           |
|   | edia/image6.wmf){width |   1.3 and \< 7        |      |           |
|   | ="3.841666666666667in" |                       |      |           |
|   | height="               |   [\>]                |      |           |
|   | 1.0902777777777777in"} | {.underline} 7 -20 dB |      |           |
|   |                        |   and \< 23           |      |           |
|   |                        |                       |      |           |
|   |                        |   [\>]                |      |           |
|   |                        | {.underline}   -40 dB |      |           |
|   |                        |   23 and \< 78        |      |           |
|   |                        |                       |      |           |
|   |                        |   \> 7                |      |           |
|   |                        | 8              -60 dB |      |           |
|   |                        |   ---------           |      |           |
|   |                        | --------- ----------- |      |           |
+---+------------------------+-----------------------+------+-----------+
| 1 | 2.2.4.23 p 24          | 3.6.4 p 29            |      | ED        |
| 9 |                        |                       |      | specifies |
| . | **Mode S Reply Pulse   | ### Mod               |      | minimum   |
|   | Shape**                | e S Reply Pulse Shape |      | and       |
| [ |                        |                       |      | maximum   |
| ] | a\. The pulse          | > a\. All Mode S      |      | rise and  |
| { | amplitude variation    | > reply pulses shall  |      | decay     |
| . | between one pulse and  | > have the following  |      | times     |
| m | any other pulse in a   | > characteristics.    |      | whereas   |
| a | reply **shall** not    | >                     |      | DO only   |
| r | exceed 2 dB.           | > Duration: See       |      | specifies |
| k |                        | > paragraph 3.6.2 c.  |      | maximum.  |
| } | b\. The pulse rise     | >                     |      |           |
|   | time **shall not**     | > Rise time: Between  |      | ED73 to   |
|   | exceed 0.1             | > 0.05 and 0.1 µs.    |      | be        |
|   | microsecond.           | >                     |      | modified  |
|   |                        | > Decay time: Between |      | to remove |
|   | c\. The pulse decay    | > 0.05 and 0.2 µs.    |      | minimum   |
|   | time **shall not**     |                       |      | rise      |
|   | exceed 0.2             | b.  The pulse         |      | times     |
|   | microsecond.           |     amplitude         |      |           |
|   |                        |     variation between |      | LEAVE     |
|   |                        |     one pulse and any |      | minimum   |
|   |                        |     other pulse in a  |      | times in  |
|   |                        |     reply shall not   |      | in line   |
|   |                        |     exceed 2 dB.      |      | with      |
|   |                        |                       |      | ICAO,     |
|   |                        |                       |      | DO181 has |
|   |                        |                       |      | them also |
|   |                        |                       |      | in        |
|   |                        |                       |      | 2         |
|   |                        |                       |      | .1.11.3.1 |
|   |                        |                       |      | but not   |
|   |                        |                       |      | 2.2.4.23  |
|   |                        |                       |      |           |
|   |                        |                       |      | SC209 to  |
|   |                        |                       |      | consider  |
|   |                        |                       |      | addition  |
|   |                        |                       |      | of        |
|   |                        |                       |      | minimum   |
|   |                        |                       |      | rise and  |
|   |                        |                       |      | decay     |
|   |                        |                       |      | time of   |
|   |                        |                       |      | 0.05 µs   |
|   |                        |                       |      | to be in  |
|   |                        |                       |      | line with |
|   |                        |                       |      | ICAO      |
|   |                        |                       |      | Annex 10  |
|   |                        |                       |      | 3.1.1.6.4 |
+---+------------------------+-----------------------+------+-----------+
| 2 | 2.4.2.3.4 p 163        | 5.4.2.3.2 p 148       | [    | DO        |
| 0 |                        |                       | ]{.m | specifies |
| . | **Frequency Spectrum   | ####                  | ark} | UF        |
|   | of Mode S Replies      |  Transmitter Spectrum |      | inte      |
|   | (§2.2.4.2.3.d)**       |                       |      | rrogation |
|   |                        | > b\. [STEP 2 - Mode  |      | whereas   |
|   | Connect the equipment  | > S]{.underline}      |      | ED        |
|   | as shown in Figure     | >                     |      | specifies |
|   | 2-32. Interrogate the  | > [Repeat Step 1 with |      | UF 11     |
|   | transponder with [a    | > Mode S \"All-Call   |      | inter     |
|   | standard Mode S        | > int                 |      | rogation. |
|   | surveillance-identity  | errogation\".]{.mark} |      | To be     |
|   | interrogation]{.mark}  |                       |      | ha        |
|   | and observe the        | Record the maximum    |      | rmonised. |
|   | spectral response of   | response in each      |      |           |
|   | the reply.             | frequency band as a   |      | To be     |
|   |                        | ratio expressed in dB |      | amended   |
|   |                        | relative to the       |      | after     |
|   |                        | centre band peak      |      | d         |
|   |                        | level.                |      | iscussion |
|   |                        |                       |      | in common |
|   |                        |                       |      | S         |
|   |                        |                       |      | C209-WG49 |
|   |                        |                       |      | meeting   |
|   |                        |                       |      | with      |
|   |                        |                       |      | manu      |
|   |                        |                       |      | facturers |
+---+------------------------+-----------------------+------+-----------+

##  Mode A/C replies: Pulse shape and spectrum

+---+------------------------+-----------------------+------+-----------+
| \ | Do-181                 | ED-73                 | Com  | Proposal  |
| # |                        |                       | ment |           |
+===+========================+=======================+======+===========+
| 2 | 2.4.2.3.1 p 160        | 5.4.3.1 p 151         |      | SC209 to  |
| 1 |                        |                       |      | consider  |
| . | **ATCRBS Reply Pulse   | **Mode A/C Replies**  |      | to Align  |
|   | Characteristics        |                       |      | DO on ED  |
|   | (§2.2.4.1)**           | > ...                 |      | regarding |
|   |                        | >                     |      | the type  |
|   | ...                    | > b\. [STEP 2 -       |      | of reply  |
|   |                        | > Mode A/C Reply      |      | for step2 |
|   | Step 2 ATCRBS Reply    | > Pulse               |      | (i.e. 15  |
|   | Pulse Shape            | > Shape]{.underline}  |      | pulses    |
|   | (§2.2.4.1.4)           | > (Paragraph 3.5.4)   |      | including |
|   |                        | >                     |      | a SPI     |
|   | Using a [standard      | > [Set the            |      | pulse).   |
|   | ATCRBS Mode A          | > transponder for a   |      |           |
|   | interrogation]{.mark}, | > 15-pulse reply      |      | SC209 to  |
|   | measure the duration   | > (Mode A with        |      | consider  |
|   | of each reply pulse.   | > SPI).]{.mark}       |      | to split  |
|   | Measure rise and decay | >                     |      | step3 in  |
|   | times of each pulse.   | > Interrogate the     |      | step3 /   |
|   | Measure the pulse      | > transponder on Mode |      | step4, a  |
|   | amplitude variations   | > A.                  |      | step 4    |
|   | of each pulse with     | >                     |      | including |
|   | respect to all other   | > Record the duration |      | the last  |
|   | pulses in the reply    | > of each reply       |      | 2         |
|   | train.                 | > pulse.              |      | sentences |
|   |                        |                       |      | of step   |
|   | ***CAUTION:** If the   | Record the rise and   |      | 3.        |
|   | detector is not known  | decay times of each   |      |           |
|   | to be linear, checks   | pulse.                |      | Agreed to |
|   | should be made to      |                       |      | make no   |
|   | determine what         | > Record the pulse    |      | changes   |
|   | amplitude points on    | > amplitude           |      | to either |
|   | the detected pulse     | > variations of each  |      | document  |
|   | correspond to the 10   | > pulse with respect  |      |           |
|   | percent and 90 percent | > to all other pulses |      |           |
|   | amplitude points of    | > in the reply train. |      |           |
|   | the RF pulses.*        |                       |      |           |
|   |                        | **CAUTION:** If the   |      |           |
|   | In addition, checks    | detector is not known |      |           |
|   | should be made to      | to be linear, checks  |      |           |
|   | determine the rise     | should be made to     |      |           |
|   | time of the detector.  | determine what        |      |           |
|   |                        | amplitude points on   |      |           |
|   | Step 3 SPI Pulse       | the detected pulse    |      |           |
|   | (§2.2.4.1.3,           | correspond to the 10% |      |           |
|   | §2.2.4.1.4 and         | and 90% amplitude     |      |           |
|   | §2.2.4.1.5)            | points of the RF      |      |           |
|   |                        | pulses. In addition,  |      |           |
|   | Momentarily activate   | checks should be made |      |           |
|   | the SPI pulse control. | to determine the rise |      |           |
|   | Interrogate the        | time of the detector. |      |           |
|   | transponder with a     |                       |      |           |
|   | standard ATCRBS Mode-A | > c\. [STEP 3 - SPI   |      |           |
|   | interrogation. Measure | > Pulse]{.underline}  |      |           |
|   | the position of the    | > (Paragraph 3.5.3    |      |           |
|   | SPI pulse with respect | > and 3.5.5)          |      |           |
|   | to the last framing    |                       |      |           |
|   | pulse and the time the | Interrogate with      |      |           |
|   | pulse remains in the   | Mode A                |      |           |
|   | reply train. Measure   | interrogations.       |      |           |
|   | the width of the SPI   |                       |      |           |
|   | pulse. With the SPI    | Activate the SPI      |      |           |
|   | pulse activated,       | pulse control.        |      |           |
|   | interrogate the        |                       |      |           |
|   | transponder with a     | Record the position   |      |           |
|   | standard ATCRBS Mode-C | of the SPI pulse with |      |           |
|   | interrogation. Verify  | respect to the last   |      |           |
|   | that the SPI pulse is  | framing pulse and the |      |           |
|   | not present in the     | time the pulse        |      |           |
|   | reply train.           | remains in the reply  |      |           |
|   |                        | train.                |      |           |
|   |                        |                       |      |           |
|   |                        | > d\. [STEP 4 - SPI   |      |           |
|   |                        | > Pulse with Mode C   |      |           |
|   |                        | > Interr              |      |           |
|   |                        | ogations]{.underline} |      |           |
|   |                        | > (Paragraph 3.5.3)   |      |           |
|   |                        |                       |      |           |
|   |                        | Interrogate with Mode |      |           |
|   |                        | C interrogations.     |      |           |
|   |                        |                       |      |           |
|   |                        | Activate the SPI      |      |           |
|   |                        | pulse control and     |      |           |
|   |                        | verify that the SPI   |      |           |
|   |                        | pulse is not          |      |           |
|   |                        | transmitted.          |      |           |
+---+------------------------+-----------------------+------+-----------+

##  Fixed Direct Data

+---+------------------------+-----------------------+------+-----------+
| \ | Do-181                 | ED-73                 | Com  | Proposal  |
| # |                        |                       | ment |           |
+===+========================+=======================+======+===========+
| 2 | 2.4.2.11.2 p 175       | 5.4.12.1 p 183        |      | Clarify   |
| 2 |                        |                       |      | in both   |
| . | **Fixed Direct Data    | **Fixed Direct Data** |      | documents |
|   | (§2.2.13.1.1)**        |                       |      | that this |
|   |                        | 2.  Test Procedure    |      | test is   |
|   | Step 4 Aircraft        |                       |      | only      |
|   | Identification Data    | > [STEP 4 ‑ Aircraft  |      | a         |
|   | (§2.2.13.1.1.c)        | > Identification      |      | pplicable |
|   |                        | > Data]{.underline}   |      | if the    |
|   | If the transponder     | >                     |      | tr        |
|   | inputs aircraft        | > Interrogate the     |      | ansponder |
|   | identification data as | > transponder with a  |      | is able   |
|   | fixed data, the        | > short               |      | to report |
|   | following test         | >                     |      | Aircraft  |
|   | applies. Interrogate   | surveillance‑altitude |      | Ident     |
|   | the transponder with a | > interrogation       |      | ification |
|   | short                  | > (UF=4) with PC, DI  |      | Data as   |
|   | surveillance-altitude  | > and SD fields set   |      | the data  |
|   | (UF=4) with PC, DI and | > to 0 and the RR     |      | available |
|   | SD fields set to 0 and | > field set to 18.    |      | on the    |
|   | the RR field set to    |                       |      | reg       |
|   | 18. Set the aircraft   | Set the aircraft      |      | istration |
|   | identification input   | identification input  |      | marking   |
|   | to the transponder to  | to the transponder to |      | input.    |
|   | 'LLLLLLLL' and verify  | 101010\...\...(etc)   |      |           |
|   | that the encoded       | and record that the   |      | Clarify   |
|   | aircraft               | identification data   |      | also that |
|   | identification data is | are properly          |      | if the    |
|   | correctly transmitted  | transmitted in the MB |      | input     |
|   | in the MB field (MB    | field of the          |      | data      |
|   | Bits 9-56 =            | transponder\'s reply. |      | becomes   |
|   | 001100001100 \...) of  |                       |      | un        |
|   | the transponder's      | > Repeat for an       |      | available |
|   | reply. Repeat with an  | > aircraft            |      | or if the |
|   | aircraft               | > identification      |      | tr        |
|   | identification input   | > input of            |      | ansponder |
|   | of '33333333' and      | > 010101\.....(etc).  |      | is        |
|   | verify that the        |                       |      | switched  |
|   | encoded aircraft       | Repeat with an        |      | off/on,   |
|   | identification data is | aircraft              |      | the       |
|   | correctly transmitted  | identification input  |      | output    |
|   | in the MB field (MB    | of ABCD1234 coded in  |      | shall be  |
|   | Bits 9-56 =            | accordance with the   |      | [TB       |
|   | 110011110011 \...) of  | character coding      |      | C]{.mark} |
|   | the transponder's      | specified in          |      |           |
|   | reply.                 | paragraph 3.21.1.13   |      | EP to     |
|   |                        | f.                    |      | make a    |
|   | Deleted step 4 of      |                       |      | separate  |
|   | 2.4.2.11.3 and         |                       |      | WP        |
|   | replaced with          |                       |      | e         |
|   |                        |                       |      | xplaining |
|   | 'Appropriate test      |                       |      | the issue |
|   | procedures are         |                       |      | and       |
|   | presented in para. 2.6 |                       |      | proposing |
|   |                        |                       |      | a new     |
|   | Also deleted step 6 of |                       |      | text      |
|   | 2.3.2.11.2 and         |                       |      |           |
|   | replaced with          |                       |      | Once new  |
|   |                        |                       |      | r         |
|   | 'Appropriate test      |                       |      | eferences |
|   | procedures are         |                       |      | a         |
|   | presented in para. 2.6 |                       |      | vailable, |
|   |                        |                       |      | delete    |
|   |                        |                       |      | para.s as |
|   |                        |                       |      | per DO181 |
+---+------------------------+-----------------------+------+-----------+

##  Variable Direct Data

+---+------------------------+-----------------------+------+-----------+
| \ | Do-181                 | ED-73                 | Com  | Proposal  |
| # |                        |                       | ment |           |
+===+========================+=======================+======+===========+
| 2 | 2.2.13.1.2 p 38        | 3.17.1 p 43           |      | [Replace  |
| 3 |                        |                       |      | ATCRBS by |
| . | **Variable Direct      | **Direct Data**       |      | Mode A/C  |
|   | Data**                 |                       |      | in the    |
|   |                        | > b\. Variable Direct |      | whole     |
|   | a\. Pressure Altitude  | > Data                |      | section   |
|   |                        | >                     |      | 3.17 of   |
|   | \(2\) Mode S           | > \(1\) Pressure      |      | the ED    |
|   |                        | > Altitude            |      | document  |
|   | \(a\) Bit 26 **shall** | >                     |      | .]{.mark} |
|   | be designated as the M | > \(ii\) Mode S       |      |           |
|   | bit and **shall** be   |                       |      |           |
|   | ZERO if the altitude   | a.  Bit 26 shall be   |      |           |
|   | is reported in feet. M |     designated as the |      |           |
|   | equals ONE **shall**   |     M bit and shall   |      |           |
|   | be reserved for        |     be ZERO if the    |      |           |
|   | possible future use to |     altitude is       |      |           |
|   | indicate that the      |     reported in feet. |      |           |
|   | altitude reporting is  |     M equals ONE      |      |           |
|   | in metric units.       |     shall be reserved |      |           |
|   |                        |     for possible      |      |           |
|   | ***Note:** Use of the  |     future use to     |      |           |
|   | M bit as defined here  |     indicate that the |      |           |
|   | does not alter any     |     altitude          |      |           |
|   | conventions regarding  |     reporting is in   |      |           |
|   | the X bit in ATCRBS    |     metric units.     |      |           |
|   | replies.*              |                       |      |           |
|   |                        | >                     |      |           |
|   |                        |  *[NOTE]{.underline}: |      |           |
|   |                        | > Use of the M bit as |      |           |
|   |                        | > defined here does   |      |           |
|   |                        | > not alter any       |      |           |
|   |                        | > conventions         |      |           |
|   |                        | > regarding the X bit |      |           |
|   |                        | > in [ATCRBS]{.mark}  |      |           |
|   |                        | > replies.*           |      |           |
+---+------------------------+-----------------------+------+-----------+
| 2 | 2.4.2.12.2 p 176/177   | 5.4.12.2.2 p 185      |      | SC209 to  |
| 4 |                        |                       |      | consider  |
| . | **Variable Direct Data | **Variable Direct     |      | addition  |
|   | (§2.2.13.1.2)**        | Data                  |      | of step   |
|   |                        | (Paragraph 3.17.1     |      | 3.9 to    |
|   | Step 3 Pressure        | b.)**                 |      | ensure    |
|   | Altitude (Mode S)      |                       |      | correct   |
|   | \[§2.2.13.1.2.a (2)\]  | > c\. [STEP 3 ‑       |      | imple     |
|   |                        | > Pressure Altitude   |      | mentation |
|   | Connect the            | >                     |      | of metric |
|   | transponder RF port to | (Mode S)]{.underline} |      | altitude  |
|   | the Mode S test set.   | >                     |      | if        |
|   | Interrogate the        | > \(1\) Connect the   |      | imp       |
|   | transponder with a     | > transponder RF port |      | lemented. |
|   | standard               | > to the transponder  |      |           |
|   | surveillance-altitude  | > test set.           |      | SC209 to  |
|   | interrogation (UF=4)   | >                     |      | consider  |
|   | with the PC, RR, DI    | > \(2\) Interrogate   |      | addition  |
|   | and SD fields set to   | > the transponder     |      | of        |
|   | ZERO and the address   | > with a standard     |      | invalid   |
|   | the same as that       | >                     |      | altitude  |
|   | provided to the        | surveillance-altitude |      | testing   |
|   | transponder. With the  | > interrogation       |      | (I.e. Add |
|   | ALT switch on, provide | > (UF=4) with the PC, |      | last      |
|   | altitude code inputs   | > RR, DI and SD       |      | sentence  |
|   | to the transponder     | > fields set to ZERO  |      | of ED in  |
|   | which should result in | > and the address the |      | DO).      |
|   | setting each of the ac | > same as that        |      |           |
|   | field bits (including  | > provided to the     |      | No action |
|   | the M bit or the Q bit | > transponder.        |      | for ED73. |
|   | if the transponder is  | >                     |      |           |
|   | equipped to report     | > \(3\) With the ALT  |      | SC209 to  |
|   | altitude in 25-foot    | > switch ON, provide  |      | adopt the |
|   | increments) of the     | > altitude code       |      | whole     |
|   | reply one at a time.   | > inputs from an      |      | test step |
|   | Verify that the        | > altitude source in  |      | 3 in      |
|   | correct bits are       | > feet quantised to   |      | section   |
|   | transmitted in the AC  | > greater than 25 ft  |      | 2.4 and   |
|   | field of the reply.    | > to the transponder  |      | Bob       |
|   | Verify that the AC     | > which should result |      | Saffell   |
|   | field is all ZEROs     | > in setting each of  |      | to        |
|   | when the ALT switch is | > the AC field bits   |      | propose   |
|   | set to \"off.\"        | > of the reply, one   |      | adoption  |
|   |                        | > at a time.          |      | in        |
|   |                        | >                     |      | section   |
|   |                        | > \(4\) Verify that   |      | 2.3       |
|   |                        | > the correct bits    |      |           |
|   |                        | > are transmitted in  |      |           |
|   |                        | > the AC field of the |      |           |
|   |                        | > reply with the Q    |      |           |
|   |                        | > bit set to 0 and    |      |           |
|   |                        | > the M bit set to 0. |      |           |
|   |                        | >                     |      |           |
|   |                        | > \(5\) With the ALT  |      |           |
|   |                        | > switch ON, provide  |      |           |
|   |                        | > altitude code       |      |           |
|   |                        | > inputs from an      |      |           |
|   |                        | > altitude source in  |      |           |
|   |                        | > feet quantised to   |      |           |
|   |                        | > 25 ft or less to    |      |           |
|   |                        | > the transponder and |      |           |
|   |                        | > verify that the     |      |           |
|   |                        | > altitude report is  |      |           |
|   |                        | > correct as a        |      |           |
|   |                        | > minimum when the    |      |           |
|   |                        | > input indicates     |      |           |
|   |                        | > pressure altitudes  |      |           |
|   |                        | > of 17 050 and 34    |      |           |
|   |                        | > 125 ft.             |      |           |
|   |                        | >                     |      |           |
|   |                        | > \(6\) Verify that   |      |           |
|   |                        | > the correct bits    |      |           |
|   |                        | > are transmitted in  |      |           |
|   |                        | > the AC field of the |      |           |
|   |                        | > reply with the Q    |      |           |
|   |                        | > bit set to 1 and    |      |           |
|   |                        | > the M bit set to 0. |      |           |
|   |                        | >                     |      |           |
|   |                        | > \(7\) With the ALT  |      |           |
|   |                        | > switch ON, provide  |      |           |
|   |                        | > altitude code       |      |           |
|   |                        | > inputs from an      |      |           |
|   |                        | > altitude source     |      |           |
|   |                        | > quantised to 25 ft  |      |           |
|   |                        | > or less to the      |      |           |
|   |                        | > transponder. Verify |      |           |
|   |                        | > that the altitude   |      |           |
|   |                        | > report is correct   |      |           |
|   |                        | > when the input      |      |           |
|   |                        | > indicates pressure  |      |           |
|   |                        | > altitudes of        |      |           |
|   |                        | > between 50 188 ft   |      |           |
|   |                        | > and 126 700 ft,     |      |           |
|   |                        | > which should result |      |           |
|   |                        | > in setting each of  |      |           |
|   |                        | > the AC field bits   |      |           |
|   |                        | > of the reply.       |      |           |
|   |                        | >                     |      |           |
|   |                        | > \(8\) Verify that   |      |           |
|   |                        | > the correct bits    |      |           |
|   |                        | > are transmitted in  |      |           |
|   |                        | > the AC field of the |      |           |
|   |                        | > reply with the Q    |      |           |
|   |                        | > bit set to 0 to     |      |           |
|   |                        | > indicate a report   |      |           |
|   |                        | > to 100 ft           |      |           |
|   |                        | > quantisation and    |      |           |
|   |                        | > the M bit set to 0. |      |           |
|   |                        | >                     |      |           |
|   |                        | > [(9) Repeat Step 3  |      |           |
|   |                        | > (1) to (8) with the |      |           |
|   |                        | > input indicating    |      |           |
|   |                        | > metric input if     |      |           |
|   |                        | > available and       |      |           |
|   |                        | > verify that the M   |      |           |
|   |                        | > bit is set to 1 in  |      |           |
|   |                        | > the AC field of all |      |           |
|   |                        | > replies.]{.mark}    |      |           |
|   |                        |                       |      |           |
|   |                        | Verify that the AC    |      |           |
|   |                        | field is all ZEROs    |      |           |
|   |                        | when the ALT switch   |      |           |
|   |                        | is set to " OFF ".    |      |           |
|   |                        |                       |      |           |
|   |                        | [Set the input        |      |           |
|   |                        | altitude data to      |      |           |
|   |                        | invalid and verify    |      |           |
|   |                        | that the AC field is  |      |           |
|   |                        | all ZEROs.]{.mark}    |      |           |
+---+------------------------+-----------------------+------+-----------+
| 2 | \-                     | [5.4.12.2.2 p         |      | [To be    |
| 5 |                        | 187]{.mark}           |      | removed   |
| . |                        |                       |      | from ED   |
|   |                        | **[Variable Direct    |      | as AA is  |
|   |                        | Data                  |      | a fixed   |
|   |                        | (Paragraph 3.17.1     |      | data. It  |
|   |                        | b.)]{.mark}**         |      | is        |
|   |                        |                       |      | already   |
|   |                        | [f. Step 6 -- Invalid |      | inc       |
|   |                        | AA]{.mark}            |      | orporated |
|   |                        |                       |      | in fixed  |
|   |                        | 1.  [Put the          |      | direct    |
|   |                        |     transponder in    |      | data.     |
|   |                        |     the Power Off     |      | Already   |
|   |                        |     Condition and set |      | done in   |
|   |                        |     the AA to all     |      | DO181 D   |
|   |                        |     ZEROs. Turn on    |      | v0.       |
|   |                        |     the transponder   |      | 8]{.mark} |
|   |                        |     and verify that a |      |           |
|   |                        |     transponder error |      |           |
|   |                        |     condition is      |      |           |
|   |                        |     set.]{.mark}      |      |           |
|   |                        |                       |      |           |
|   |                        | > [Note : the         |      |           |
|   |                        | > transponder will    |      |           |
|   |                        | > normally either go  |      |           |
|   |                        | > into Standby State, |      |           |
|   |                        | > revert to a Mode    |      |           |
|   |                        | > A/C transponder or  |      |           |
|   |                        | > return to the Power |      |           |
|   |                        | > Off                 |      |           |
|   |                        | > Condition.]{.mark}  |      |           |
|   |                        |                       |      |           |
|   |                        | 2.  [Repeat this test |      |           |
|   |                        |     with the AA set   |      |           |
|   |                        |     to all            |      |           |
|   |                        |     ONEs.]{.mark}     |      |           |
|   |                        |                       |      |           |
|   |                        | 3.  [Put the          |      |           |
|   |                        |     transponder in    |      |           |
|   |                        |     the Power On      |      |           |
|   |                        |     Condition with an |      |           |
|   |                        |     AA set to ONE for |      |           |
|   |                        |     the first bit and |      |           |
|   |                        |     ZEROs for all     |      |           |
|   |                        |     other bits.       |      |           |
|   |                        |     Verify that the   |      |           |
|   |                        |     transponder       |      |           |
|   |                        |     functions         |      |           |
|   |                        |     normally as       |      |           |
|   |                        |     indicated in      |      |           |
|   |                        |     steps 1 and       |      |           |
|   |                        |     2.]{.mark}        |      |           |
|   |                        |                       |      |           |
|   |                        | 4.  [Without putting  |      |           |
|   |                        |     the transponder   |      |           |
|   |                        |     in Power Off      |      |           |
|   |                        |     Condition change  |      |           |
|   |                        |     the AA to all     |      |           |
|   |                        |     ZEROs. Verify     |      |           |
|   |                        |     that the          |      |           |
|   |                        |     transponder       |      |           |
|   |                        |     generates a       |      |           |
|   |                        |     diagnostic error  |      |           |
|   |                        |     message for       |      |           |
|   |                        |     maintenance and   |      |           |
|   |                        |     that it keeps     |      |           |
|   |                        |     operating using   |      |           |
|   |                        |     the initial AA    |      |           |
|   |                        |     read during the   |      |           |
|   |                        |     power-on          |      |           |
|   |                        |     initialisation    |      |           |
|   |                        |     process (first    |      |           |
|   |                        |     bit set to ONE    |      |           |
|   |                        |     and all other     |      |           |
|   |                        |     bits set to       |      |           |
|   |                        |     ZEROs).]{.mark}   |      |           |
|   |                        |                       |      |           |
|   |                        | 5.  [Repeat this test |      |           |
|   |                        |     with the AA set   |      |           |
|   |                        |     to all            |      |           |
|   |                        |     ONEs.]{.mark}     |      |           |
|   |                        |                       |      |           |
|   |                        | 6.  [Repeat with the  |      |           |
|   |                        |     remaining         |      |           |
|   |                        |     twenty‑three      |      |           |
|   |                        |     different         |      |           |
|   |                        |     transponder       |      |           |
|   |                        |     addresses each    |      |           |
|   |                        |     consisting of 23  |      |           |
|   |                        |     ZEROs and a       |      |           |
|   |                        |     single            |      |           |
|   |                        |     ONE.]{.mark}      |      |           |
+---+------------------------+-----------------------+------+-----------+
| 2 | 2.4.2.12.2 p 176/177   | \-                    | No   | Same      |
| 6 |                        |                       | c    | procedure |
| . | **Variable Direct Data |                       | orre | to be     |
|   | (§2.2.13.1.2)**        |                       | spon | added in  |
|   |                        |                       | ding | ED73. to  |
|   | Step 6 Aircraft        |                       | test | be        |
|   | Identification Data    |                       | p    | checked   |
|   | (§2.2.13.1.2.e)        |                       | roce | with EP   |
|   |                        |                       | dure | action on |
|   | If the transponder     |                       | in   | fixed     |
|   | inputs aircraft        |                       | ED   | direct    |
|   | identification data as |                       |      | data.     |
|   | variable data, the     |                       |      |           |
|   | following test         |                       |      | Point to  |
|   | applies. Interrogate   |                       |      | new       |
|   | the transponder with a |                       |      | procedure |
|   | short surveillance     |                       |      | in ELS    |
|   | altitude (UF=4) with   |                       |      | section   |
|   | PC, DI and SD fields   |                       |      |           |
|   | set to 0 and the RR    |                       |      | Include   |
|   | field set to 18. Set   |                       |      | in ED     |
|   | the aircraft           |                       |      | same      |
|   | identification input   |                       |      | procedure |
|   | to the transponder to  |                       |      | as in DO  |
|   | 'LLLLLLLL' and verify  |                       |      | and       |
|   | that the encoded       |                       |      | specify   |
|   | aircraft               |                       |      | that it   |
|   | identification data is |                       |      | co        |
|   | correctly transmitted  |                       |      | rresponds |
|   | in the MB field (MB    |                       |      | to the    |
|   | Bits 9-56 =            |                       |      | setting   |
|   | 001100001100 \...) of  |                       |      | where the |
|   | the transponder's      |                       |      | Aircraft  |
|   | reply. Repeat with an  |                       |      | Ident     |
|   | aircraft               |                       |      | ification |
|   | identification input   |                       |      | is        |
|   | of '33333333' and      |                       |      | variable, |
|   | verify that the        |                       |      | i.e.      |
|   | encoded aircraft       |                       |      | different |
|   | identification data is |                       |      | of        |
|   | correctly transmitted  |                       |      | reg       |
|   | in the MB field (MB    |                       |      | istration |
|   | Bits 9-56 =            |                       |      | marking   |
|   | 110011110011 \...) of  |                       |      | (e.g.     |
|   | the transponder's      |                       |      | call      |
|   | reply.                 |                       |      | sign).    |
|   |                        |                       |      |           |
|   |                        |                       |      | [Check if |
|   |                        |                       |      | test is   |
|   |                        |                       |      | complete  |
|   |                        |                       |      | (e.g.     |
|   |                        |                       |      | invalid   |
|   |                        |                       |      | input)    |
|   |                        |                       |      | .]{.mark} |
+---+------------------------+-----------------------+------+-----------+

##  SPI data

+---+------------------------+-----------------------+------+-----------+
| \ | Do-181                 | ED-73                 | Com  | Proposal  |
| # |                        |                       | ment |           |
+===+========================+=======================+======+===========+
| 2 | 2.2.4.1.3 p 22         | 3.5.3 p 27            |      | Different |
| 7 |                        |                       |      | speci     |
| . | **ATCRBS-SPI**         | ### Mode A/C S        |      | fications |
|   |                        | pecial Position Ident |      | in the    |
|   | In addition to the     | ification (SPI) Pulse |      | documents |
|   | information pulses     |                       |      | could be  |
|   | provided, an SPI       | > a\. In addition to  |      | clearer.  |
|   | pulse, which may be    | > the information     |      |           |
|   | used with any of the   | > pulses, a SPI       |      | Co        |
|   | other information      | > pulse, which may be |      | nclusion: |
|   | pulses upon request,   | > used with any of    |      |           |
|   | **shall** be provided  | > the other           |      | [Add in   |
|   | at a spacing 4.35      | > information pulses  |      | ED 73 at  |
|   | microseconds following | > upon request, shall |      | the end   |
|   | the last framing       | > be provided at a    |      | of bullet |
|   | pulse.                 | > spacing 4.35 µs     |      | a]{.mark} |
|   |                        | > following the last  |      |           |
|   | The SPI pulse          | > framing pulse [of   |      | ['The SPI |
|   | **shall** be initiated | > Mode A replies      |      | pulse     |
|   | by an IDENT switch.    | > only.]{.mark}       |      | **shall** |
|   |                        | >                     |      | not be    |
|   | Upon activation of the | > b\. The SPI pulse   |      | tr        |
|   | IDENT switch, the SPI  | > shall [only]{.mark} |      | ansmitted |
|   | pulse **shall** be     | > be initiated by an  |      | when      |
|   | transmitted when       | > IDENT switch.       |      | replying  |
|   | replying to ATCRBS     |                       |      | to Mode C |
|   | Mode A interrogations  | c\. Upon activation   |      | interr    |
|   | for a period of 18     | of the IDENT switch,  |      | ogations. |
|   | ±1.0 seconds.          | the SPI pulse shall   |      | ']{.mark} |
|   |                        | be transmitted when   |      |           |
|   | [The SPI pulse         | replying to Mode A    |      |           |
|   | **shall** be           | interrogations for a  |      |           |
|   | transmitted only if    | period of 18 ±1.0     |      |           |
|   | the IDENT switch is    | seconds.              |      |           |
|   | first                  |                       |      |           |
|   | activated.]{.mark}     |                       |      |           |
|   |                        |                       |      |           |
|   | [The SPI pulse         |                       |      |           |
|   | **shall** not be       |                       |      |           |
|   | transmitted when       |                       |      |           |
|   | replying to Mode C     |                       |      |           |
|   | i                      |                       |      |           |
|   | nterrogations.]{.mark} |                       |      |           |
+---+------------------------+-----------------------+------+-----------+
| 2 |                        | 3.6.3 p 29            |      | No        |
| 8 |                        |                       |      | e         |
| . |                        | ### Special Position  |      | quivalent |
|   |                        |  Identification (SPI) |      | spec      |
|   |                        |                       |      | ification |
|   |                        | > a\. When manually   |      | in the    |
|   |                        | > activated, the SPI  |      | Mode S    |
|   |                        | > condition is        |      | replies   |
|   |                        | > indicated in the FS |      | section   |
|   |                        | > field of Mode S     |      | of the DO |
|   |                        | > replies (DF = 4, 5, |      | document. |
|   |                        | > 20 and 21).         |      |           |
|   |                        | >                     |      | In fact   |
|   |                        | > b\. This            |      | there a   |
|   |                        | > information shall   |      | section   |
|   |                        | > be present for a    |      | on SPI in |
|   |                        | > period of 18 ±1.0   |      | 2.        |
|   |                        | > seconds, after      |      | 2.18.2.7d |
|   |                        | > activation.         |      | for level |
|   |                        |                       |      | 1         |
|   |                        |                       |      | tr        |
|   |                        |                       |      | ansponder |
|   |                        |                       |      | it does   |
|   |                        |                       |      | not       |
|   |                        |                       |      | include   |
|   |                        |                       |      | df20/21   |
|   |                        |                       |      | but       |
|   |                        |                       |      | er        |
|   |                        |                       |      | roneously |
|   |                        |                       |      | include   |
|   |                        |                       |      | ES.       |
|   |                        |                       |      |           |
|   |                        |                       |      | For       |
|   |                        |                       |      | level2    |
|   |                        |                       |      | section   |
|   |                        |                       |      | 2         |
|   |                        |                       |      | .2.19.1.6 |
|   |                        |                       |      | makes     |
|   |                        |                       |      | reference |
|   |                        |                       |      | to FS.    |
|   |                        |                       |      |           |
|   |                        |                       |      | SC 209 to |
|   |                        |                       |      | check     |
|   |                        |                       |      | that SPI  |
|   |                        |                       |      | is        |
|   |                        |                       |      | correctly |
|   |                        |                       |      | covered.  |
|   |                        |                       |      | SC209     |
|   |                        |                       |      | will      |
|   |                        |                       |      | update    |
|   |                        |                       |      | this      |
|   |                        |                       |      | section   |
|   |                        |                       |      | 2         |
|   |                        |                       |      | .2.18.2.7 |
|   |                        |                       |      |           |
|   |                        |                       |      | SPI is    |
|   |                        |                       |      | tested in |
|   |                        |                       |      | para.     |
|   |                        |                       |      | 2.5.4.7   |
|   |                        |                       |      |           |
|   |                        |                       |      | There is  |
|   |                        |                       |      | no        |
|   |                        |                       |      | corr      |
|   |                        |                       |      | esponding |
|   |                        |                       |      | test      |
|   |                        |                       |      | procedure |
|   |                        |                       |      | in ED     |
|   |                        |                       |      | 5.4.3.2.2 |
|   |                        |                       |      | Mode S    |
|   |                        |                       |      | replies,  |
|   |                        |                       |      | there is  |
|   |                        |                       |      | one but   |
|   |                        |                       |      | in the ES |
|   |                        |                       |      | control.  |
|   |                        |                       |      |           |
|   |                        |                       |      | Same      |
|   |                        |                       |      | comment   |
|   |                        |                       |      | for DO,   |
|   |                        |                       |      | as there  |
|   |                        |                       |      | is no     |
|   |                        |                       |      | req       |
|   |                        |                       |      | uirement. |
+---+------------------------+-----------------------+------+-----------+
| 2 | 2.2.13.1.2 p 39        | 3.17.1 p 44           |      | [Remove   |
| 9 |                        |                       |      | the       |
| . | **Variable Direct      | ### Direct Data       |      | remark in |
|   | Data**                 |                       |      | ED        |
|   |                        | ...                   |      | c         |
|   | d\. Special Position   |                       |      | onsistent |
|   | Identification (SPI)   | > b\. Variable Direct |      | with      |
|   |                        | > Data                |      | D         |
|   | In the ATCRBS mode, an |                       |      | O]{.mark} |
|   | SPI pulse **shall** be | ...                   |      |           |
|   | transmitted upon       |                       |      | (Could be |
|   | request, following a   | > \(4\) the presence  |      | more      |
|   | Mode A reply. In the   | > of the Special      |      | c         |
|   | FS field of Mode S     | > Position            |      | onsistent |
|   | replies, an equivalent | > Identification      |      | to        |
|   | of the ATCRBS SPI      | > (SPI).              |      | reference |
|   | pulse **shall** be     | >                     |      | 3.5.3 in  |
|   | transmitted upon the   | > In Mode A/C, an SPI |      | ED and    |
|   | same request. The code | > pulse shall be      |      | 2.2.4.1   |
|   | is transmitted for 18  | > transmitted upon    |      | in DO.)   |
|   | ±1.0 seconds after     | > request, following  |      |           |
|   | initiation and can be  | > a Mode A reply. In  |      |           |
|   | reinitiated at any     | > the FS field of     |      |           |
|   | time.                  | > Mode S replies, an  |      |           |
|   |                        | > equivalent of the   |      |           |
|   |                        | > SPI pulse shall be  |      |           |
|   |                        | > transmitted upon    |      |           |
|   |                        | > the same request.   |      |           |
|   |                        | > The code is         |      |           |
|   |                        | > transmitted for     |      |           |
|   |                        | > 18 ±1.0 seconds     |      |           |
|   |                        | > after initiation    |      |           |
|   |                        | > and can be          |      |           |
|   |                        | > reinitiated at any  |      |           |
|   |                        | > time.               |      |           |
|   |                        | >                     |      |           |
|   |                        | > *(repetetive        |      |           |
|   |                        | > statement, ED 73 B  |      |           |
|   |                        | > 3.5.3)*             |      |           |
+---+------------------------+-----------------------+------+-----------+

##  Miscellaneous

+---+------------------------+-----------------------+------+-----------+
| \ | Do-181                 | ED-73                 | Com  | Proposal  |
| # |                        |                       | ment |           |
+===+========================+=======================+======+===========+
| 3 | 1.6.2 p 9/10           |                       | What | General   |
| 0 |                        |                       | is   | d         |
| . | **Detailed Test        |                       | the  | iscussion |
|   | Procedures**           |                       | mea  | on        |
|   |                        |                       | ning | envi      |
|   | Detailed test          |                       | of   | ronmental |
|   | procedures for         |                       | this | tests     |
|   | [hardware              |                       | st   |           |
|   | qualifications in      |                       | atem | Leave     |
|   | ambient                |                       | ent? | till      |
|   | conditions]{.mark} are |                       |      | envi      |
|   | specified in           |                       |      | ronmental |
|   | Subsection §2.4. The   |                       |      | test      |
|   | test procedures        |                       |      | d         |
|   | contained in           |                       |      | iscussion |
|   | Subsection §2.5 verify |                       |      |           |
|   | the transponder\'s     |                       |      |           |
|   | surveillance and       |                       |      |           |
|   | communication          |                       |      |           |
|   | protocols. These tests |                       |      |           |
|   | are conducted at the   |                       |      |           |
|   | equipment level and    |                       |      |           |
|   | are intended to        |                       |      |           |
|   | provide a laboratory   |                       |      |           |
|   | means of demonstrating |                       |      |           |
|   | compliance with the    |                       |      |           |
|   | requirements of        |                       |      |           |
|   | Subsections §2.1 and   |                       |      |           |
|   | §2.2. Test results may |                       |      |           |
|   | be used by equipment   |                       |      |           |
|   | manufacturers as       |                       |      |           |
|   | design guidance, for   |                       |      |           |
|   | monitoring             |                       |      |           |
|   | manufacturing          |                       |      |           |
|   | compliance and, in     |                       |      |           |
|   | certain cases, for     |                       |      |           |
|   | obtaining formal       |                       |      |           |
|   | approval of equipment  |                       |      |           |
|   | design and             |                       |      |           |
|   | manufacture.           |                       |      |           |
+---+------------------------+-----------------------+------+-----------+

##  ME for extended squitter

+---+------------------------+-----------------------+------+-----------+
| \ | Do-181                 | ED-73                 | Com  | Proposal  |
| # |                        |                       | ment |           |
+===+========================+=======================+======+===========+
| 3 | 2.2.23.1.8 p 129       | 3.21.2.6.8 p 89       |      | SC209 to  |
| 1 |                        |                       |      | check and |
| . | **Subfields in ME for  | #                     |      | correct   |
|   | Extended Squitter**    | #### Subfields in ME  |      | reference |
|   |                        | for Extended Squitter |      | for Code  |
|   | SSS, the 2-bit (38-39) |                       |      | 3 (it     |
|   | Surveillance Status    | SSS, the 2-bit        |      | shall     |
|   | Subfield in ME shall   | (38,39) Surveillance  |      | refer to  |
|   | report the             | Status Subfield in ME |      | §         |
|   | surveillance status of | shall report the      |      | 2.2.18.   |
|   | the transponder when   | surveillance status   |      | 2.7.**d** |
|   | this field contains    | of the transponder    |      | in DO)    |
|   | the airborne position  | when ME contains the  |      |           |
|   | squitter report. The   | airborne position     |      |           |
|   | following codes have   | squitter report. The  |      |           |
|   | been assigned:         | following codes have  |      |           |
|   |                        | been assigned:        |      |           |
|   | ![](me                 |                       |      |           |
|   | dia/image7.wmf){width= |   --                  |      |           |
|   | "3.8743055555555554in" | - --- --------------- |      |           |
|   | height="               |   0   =   No status   |      |           |
|   | 0.6847222222222222in"} |                       |      |           |
|   |                        |          information. |      |           |
|   |                        |                       |      |           |
|   |                        |   1   =   Transponder |      |           |
|   |                        |           reporting   |      |           |
|   |                        |                       |      |           |
|   |                        |       permanent alert |      |           |
|   |                        |           condition   |      |           |
|   |                        |                       |      |           |
|   |                        |         (3.20.2.7 a). |      |           |
|   |                        |                       |      |           |
|   |                        |   2   =   Transponder |      |           |
|   |                        |           reporting a |      |           |
|   |                        |                       |      |           |
|   |                        |       temporary alert |      |           |
|   |                        |           condition   |      |           |
|   |                        |                       |      |           |
|   |                        |         (3.20.2.7 a). |      |           |
|   |                        |                       |      |           |
|   |                        |   3   =   Transponder |      |           |
|   |                        |                       |      |           |
|   |                        |         reporting SPI |      |           |
|   |                        |           condition   |      |           |
|   |                        |                       |      |           |
|   |                        |         (3.20.2.7 c). |      |           |
|   |                        |   --                  |      |           |
|   |                        | - --- --------------- |      |           |
+---+------------------------+-----------------------+------+-----------+

## Standard transaction interfaces

+---+------------------------+-----------------------+------+-----------+
| \ | Do-181                 | ED-73                 | Com  | Proposal  |
| # |                        |                       | ment |           |
+===+========================+=======================+======+===========+
| 3 | The requirement and    |                       |      |           |
| 2 | test sections related  |                       |      |           |
| . | to Standard            |                       |      |           |
|   | Transaction interfaces |                       |      |           |
|   | need to be discussed   |                       |      |           |
|   | because of various     |                       |      |           |
|   | issues like ADLP can   |                       |      |           |
|   | be partly outside the  |                       |      |           |
|   | transponder and partly |                       |      |           |
|   | inside (see below), is |                       |      |           |
|   | it needed to address   |                       |      |           |
|   | UF 24, etc.            |                       |      |           |
+---+------------------------+-----------------------+------+-----------+
| 3 | 2.2.13.3.1 p 42        | 3.17.3 p 46           |      | [An item  |
| 3 |                        |                       |      | 6         |
| . | ### Standard           | ### Standard T        |      | identical |
|   | Transaction Interfaces | ransaction Interfaces |      | to item f |
|   |                        |                       |      | of DO     |
|   | **Uplink Interface**   | > c\. Uplink          |      | shall be  |
|   |                        | > Interface           |      | added in  |
|   | f\. Transponder        |                       |      | ED        |
|   | Capability *--* The    |                       |      | .]{.mark} |
|   | transponder datalink   |                       |      |           |
|   | communication capacity |                       |      | [WG49     |
|   | information **shall**  |                       |      | decided   |
|   | be made available to   |                       |      | to add    |
|   | the ADLP. This         |                       |      | bullet f  |
|   | information includes   |                       |      | in ED to  |
|   | the ELM capacity of    |                       |      | be        |
|   | the transponder and    |                       |      | c         |
|   | the ability of the     |                       |      | onsistent |
|   | transponder to support |                       |      | with      |
|   | the enhanced datalink  |                       |      | DO        |
|   | protocols.             |                       |      | .]{.mark} |
|   |                        |                       |      |           |
|   | ***Note:** This        |                       |      | There is  |
|   | information is used by |                       |      | no        |
|   | the ADLP to build the  |                       |      | e         |
|   | datalink capability*   |                       |      | quivalent |
|   |                        |                       |      | test      |
|   | *report.*              |                       |      | procedure |
|   |                        |                       |      | in DO and |
|   |                        |                       |      | of course |
|   |                        |                       |      | in ED     |
|   |                        |                       |      |           |
|   |                        |                       |      | A test    |
|   |                        |                       |      | should be |
|   |                        |                       |      | d         |
|   |                        |                       |      | eveloped. |
|   |                        |                       |      | SC209     |
|   |                        |                       |      | will      |
|   |                        |                       |      | develop   |
|   |                        |                       |      | the       |
|   |                        |                       |      | required  |
|   |                        |                       |      | test and  |
|   |                        |                       |      | ED73 will |
|   |                        |                       |      | include   |
|   |                        |                       |      | this test |
+---+------------------------+-----------------------+------+-----------+
| 3 | 2.4.2.12.3 p 177       | 5.4.12.3 p 186/187    |      | To modify |
| 4 |                        |                       |      | ED to     |
| . | **Standard Transaction | ##### Standard        |      | also      |
|   | Interfaces             |  Transaction Interfac |      | exclude   |
|   | (§2.2.13.3)**          | es (Paragraph 3.17.3) |      | DF24 for  |
|   |                        |                       |      | Downlink  |
|   | Step l Uplink          | ##### Test Procedure  |      | request   |
|   | Interface Information  |                       |      | ie. RC=3  |
|   | Content (§2.2.13.3.1 a | Connect the equipment |      | In ED the |
|   | and e)                 | as shown in [Figure   |      | 3 steps   |
|   |                        | 5.1]{.underline}.     |      | shall     |
|   | Interrogate the        |                       |      | specify   |
|   | transponder with valid | > a\. [STEP 1 ‑       |      | "[UF=0,   |
|   | Mode S interrogations  | > Uplink Interface    |      | 11, 16,   |
|   | of all uplink formats  | > Information         |      | and 24    |
|   | which the transponder  | >                     |      | (when it  |
|   | is designed to accept, |  Content]{.underline} |      | is a      |
|   | including broadcast    | > (Paragraph 3.17.3   |      | request   |
|   | interrogations. Verify | > c.)                 |      | for a     |
|   | that all fields        | >                     |      | downlink  |
|   | (possibly excluding    | > Interrogate the     |      | ELM)]{.   |
|   | AP) of the             | > transponder with    |      | mark}..." |
|   | interrogations are     | > valid Mode S        |      | according |
|   | passed correctly       | > interrogations      |      | to        |
|   | through the            | > excluding [UF 0, UF |      | 3.17.3.   |
|   | transponder and except | > 11 and UF           |      |           |
|   | for [UF=0, 11, 16, and | > 16]{.mark} of all   |      | SC209 and |
|   | 24 (when it is a       | > uplink formats      |      | WG49 to   |
|   | request for a downlink | > which the           |      | check if  |
|   | ELM)]{.mark}, appear   | > transponder is      |      | the same  |
|   | at the uplink          | > designed to accept, |      | exclusion |
|   | interface. Make        | > including broadcast |      | applies   |
|   | additional valid       | > interrogations.     |      | to all    |
|   | interrogations with    | >                     |      | steps.    |
|   | the uplink formats     | > Record that all     |      |           |
|   | [(excluding UF=11 and  | > fields (possibly    |      |           |
|   | UF=24)]{.mark} and     | > excluding AP) of    |      |           |
|   | field content randomly | > the interrogations  |      |           |
|   | chosen. Verify proper  | > are passed          |      |           |
|   | output of the uplink   | > correctly through   |      |           |
|   | interface. Verify that | > the transponder and |      |           |
|   | broadcast              | > appear at the       |      |           |
|   | interrogations are     | > uplink interface.   |      |           |
|   | identified as such,    | >                     |      |           |
|   | either by AP content   | > Make additional     |      |           |
|   | or by a special        | > valid               |      |           |
|   | purpose code.          | > interrogations with |      |           |
|   |                        | > the Uplink Formats  |      |           |
|   | Step 2 Uplink          | > and field content   |      |           |
|   | Interface, "No-Storage | > randomly chosen.    |      |           |
|   | Design"                | >                     |      |           |
|   | (§2.2.13.3.1.b)        | > Record proper       |      |           |
|   |                        | > output of the       |      |           |
|   | Interrogate the        | > uplink interface.   |      |           |
|   | transponder with valid |                       |      |           |
|   | Mode S interrogations  | Verify and record     |      |           |
|   | of all uplink formats  | that broadcast        |      |           |
|   | which the transponder  | interrogations are    |      |           |
|   | is designed to accept. | identified as such,   |      |           |
|   | Verify that all data   | either by AP content  |      |           |
|   | appear correctly at    | or a special purpose  |      |           |
|   | the uplink interface   | code.                 |      |           |
|   | prior to the start of  |                       |      |           |
|   | the transponder reply. | > b\. [STEP 2 ‑       |      |           |
|   |                        | > Uplink Interface,   |      |           |
|   | Step 3 Uplink          | > \"No‑Storage\"      |      |           |
|   | Interface, "Storage    | > Design]{.underline} |      |           |
|   | Design" Acceptance     | > (Paragraph 3.17.3   |      |           |
|   | Rate (§2.2.13.3.1.c)   | > c.)                 |      |           |
|   |                        | >                     |      |           |
|   | Interrogate the        | > Interrogate the     |      |           |
|   | transponder with valid | > transponder with    |      |           |
|   | Mode S interrogations  | > valid Mode S        |      |           |
|   | (both short and long)  | > interrogations      |      |           |
|   | at the rates and time  | > (including          |      |           |
|   | periods specified in   | > broadcast but       |      |           |
|   | §2.2.3.4.2. Verify     | > [excluding UF=11    |      |           |
|   | that all data appear   | > and UF=24]{.mark})  |      |           |
|   | correctly at the       | > of all Uplink       |      |           |
|   | uplink interface.      | > Formats which the   |      |           |
|   |                        | > transponder is      |      |           |
|   |                        | > designed to accept. |      |           |
|   |                        | >                     |      |           |
|   |                        | > Record that all     |      |           |
|   |                        | > data appear         |      |           |
|   |                        | > correctly at the    |      |           |
|   |                        | > uplink interface    |      |           |
|   |                        | > prior to the        |      |           |
|   |                        | > start of the        |      |           |
|   |                        | > transponder reply.  |      |           |
|   |                        | >                     |      |           |
|   |                        | > c\. [STEP 3 ‑       |      |           |
|   |                        | > Uplink Interface,   |      |           |
|   |                        | > \"Storage Design\"  |      |           |
|   |                        | > Acceptance          |      |           |
|   |                        | > Rate]{.underline}   |      |           |
|   |                        | > (Paragraph 3.17.3   |      |           |
|   |                        | > c.)                 |      |           |
|   |                        | >                     |      |           |
|   |                        | > Interrogate the     |      |           |
|   |                        | > transponder with    |      |           |
|   |                        | > valid Mode S        |      |           |
|   |                        | > interrogations      |      |           |
|   |                        | > (both short and     |      |           |
|   |                        | > long) at the rates  |      |           |
|   |                        | > and time periods    |      |           |
|   |                        | > specified in        |      |           |
|   |                        | > Paragraph 3.17.3 c. |      |           |
|   |                        | >                     |      |           |
|   |                        | > Record that all     |      |           |
|   |                        | > data appear         |      |           |
|   |                        | > correctly at the    |      |           |
|   |                        | > uplink interface.   |      |           |
+---+------------------------+-----------------------+------+-----------+
| 3 | 2.4.2.12.3 p 177/178   | 5.4.12.3 p 187        |      | ~~Both in |
| 5 |                        |                       |      | DO and ED |
| . | **Standard Transaction | ##### Standard        |      | specify   |
|   | Interfaces             |  Transaction Interfac |      | "[valid   |
|   | (§2.2.13.3)**          | es (Paragraph 3.17.3) |      | long Mode |
|   |                        |                       |      | S         |
|   | ...                    | ##### Test Procedure  |      | inter     |
|   |                        |                       |      | rogations |
|   | Step 4 Uplink          | ...                   |      | (**UF     |
|   | Interface,             |                       |      | 2         |
|   | Non-acceptance         | > d\. [STEP 4 ‑       |      | 0/21**)]{ |
|   | (§2.2.13.3.1.d)        | > Uplink Interface,   |      | .mark}"~~ |
|   |                        | > Non‑ac              |      |           |
|   | Interrogate the        | ceptance]{.underline} |      | [Remove   |
|   | transponder with valid | > (Paragraph 3.17.3   |      | the last  |
|   | long Mode S            | > c.)                 |      | statement |
|   | interrogations at a    | >                     |      | of ED as  |
|   | rate exceeding the one | > Interrogate the     |      | the two   |
|   | specified in           | > transponder with    |      | options   |
|   | §2.2.3.4.2 for the     | > valid long Mode S   |      | are now   |
|   | longest time period.   | > interrogations at a |      | accepted  |
|   | Verify that the        | > rate exceeding the  |      | by        |
|   | transponder does not   | > one specified in    |      | ICAO      |
|   | accept interrogations  | > Paragraph 3.17.3    |      | .]{.mark} |
|   | after the rate for     | > c.(4) for the       |      |           |
|   | which the transponder  | > longest time        |      | Add       |
|   | is designed. Also,     | > period.             |      | reference |
|   | verify that all data   | >                     |      | to the    |
|   | correctly appear at    | > Record that the     |      | new ICAO  |
|   | the uplink interface   | > transponder does    |      | Annex 10  |
|   | for all accepted       | > not accept          |      | text      |
|   | interrogations.        | > interrogations      |      | 3.1.2.    |
|   |                        | > after the rate for  |      | 4.1.2.3 + |
|   |                        | > which the           |      | new note  |
|   |                        | > transponder is      |      |           |
|   |                        | > designed has been   |      | New note  |
|   |                        | > exceeded.           |      | still to  |
|   |                        | >                     |      | be agreed |
|   |                        | > Record that all     |      |           |
|   |                        | > data correctly      |      |           |
|   |                        | > appear at the       |      |           |
|   |                        | > uplink interface    |      |           |
|   |                        | > for all accepted    |      |           |
|   |                        | > interrogations.     |      |           |
|   |                        | >                     |      |           |
|   |                        | > [With the uplink    |      |           |
|   |                        | > interface           |      |           |
|   |                        | > disconnected record |      |           |
|   |                        | > that the            |      |           |
|   |                        | > transponder does    |      |           |
|   |                        | > not reply to valid  |      |           |
|   |                        | > long Mode S         |      |           |
|   |                        | > in                  |      |           |
|   |                        | terrogations.]{.mark} |      |           |
+---+------------------------+-----------------------+------+-----------+
| 3 | 2.4.2.12.3 p 178       | 5.4.12.3 p 188        | re   | Section   |
| 6 |                        |                       | peti | 2.3       |
| . | **Standard Transaction | ##### Standard        | tion | covers    |
|   | Interfaces             |  Transaction Interfac | of   | envi      |
|   | (§2.2.13.3)**          | es (Paragraph 3.17.3) | test | ronmental |
|   |                        |                       | with | testing.  |
|   | ...                    | ##### Test Procedure  | 5555 | This is   |
|   |                        |                       | 5... | an        |
|   | Step 5 Downlink        | ...                   | is   | example   |
|   | Interface, Information |                       | not  | of        |
|   | Content                | > e\. [STEP 5 ‑       | incl | d         |
|   | (§2.2.13.3.2.a)        | > Downlink Interface, | uded | ifference |
|   |                        | > Information         | in   | with      |
|   | Insert an all ONEs     | >                     | the  | testing   |
|   | input. Interrogate the |  Content]{.underline} | c    | in normal |
|   | transponder with all   | > (Paragraph 3.17.3   | orre | co        |
|   | uplink formats that it | > d.)                 | spon | nditions. |
|   | is designed to accept  | >                     | ding |           |
|   | (one interrogation of  | > Inject an all ONEs  | § of | See       |
|   | each format, RR=16 for | > input directed to   | sec  | action on |
|   | long interrogations).  | > the MB message      | tion | envi      |
|   | Verify that all bits   | > buffer accessed by  | 2.3  | ronmental |
|   | in the transponder     | > RR = 16.            | of   | testing.  |
|   | replies, not set by    | >                     | the  |           |
|   | transponder protocol   | > Interrogate the     | DO   | Discuss   |
|   | requirements, are ONE. | > transponder with    | d    | under     |
|   | Verify that all fields | > all Uplink Formats  | ocum | envi      |
|   | in the replies, set by | > that it is designed | ent. | ronmental |
|   | transponder protocol,  | > to accept (one      |      | testing   |
|   | have the correct       | > interrogation of    |      |           |
|   | value. Repeat this     | > each format, RR=16  |      |           |
|   | procedure with MB      | > for long            |      |           |
|   | field data context 55  | > interrogations).    |      |           |
|   | 5555 5555 5555.        | >                     |      |           |
|   |                        | > Record that all     |      |           |
|   |                        | > bits in the         |      |           |
|   |                        | > transponder         |      |           |
|   |                        | > replies, not set by |      |           |
|   |                        | > transponder         |      |           |
|   |                        | > protocol            |      |           |
|   |                        | > requirements, are   |      |           |
|   |                        | > ONE.                |      |           |
|   |                        | >                     |      |           |
|   |                        | > Record that all     |      |           |
|   |                        | > fields in the       |      |           |
|   |                        | > replies, set by     |      |           |
|   |                        | > transponder         |      |           |
|   |                        | > protocol, have the  |      |           |
|   |                        | > correct value.      |      |           |
|   |                        | >                     |      |           |
|   |                        | > Repeat the 3        |      |           |
|   |                        | > previous points     |      |           |
|   |                        | > with MB field data  |      |           |
|   |                        | > context 55 5555     |      |           |
|   |                        | > 5555 5555.          |      |           |
+---+------------------------+-----------------------+------+-----------+
| 3 | 2.4.2.12.3 p 178       | 5.4.12.3 p 188        |      | SC209 to  |
| 7 |                        |                       |      | consider  |
| . | **Standard Transaction | ##### Standard        |      | addition  |
|   | Interfaces             |  Transaction Interfac |      | of green  |
|   | (§2.2.13.3)**          | es (Paragraph 3.17.3) |      | text to   |
|   |                        |                       |      | cover the |
|   | ...                    | ##### Test Procedure  |      | e         |
|   |                        |                       |      | xtraction |
|   | Step 7 Downlink        | ...                   |      | of all    |
|   | Interface, "Storage    |                       |      | r         |
|   | Design" Buffer Rate,   | > g\. [STEP 7 ‑       |      | egisters. |
|   | Buffer Function        | > Downlink Interface, |      |           |
|   | (§2.2.13.3.2.c)        | > \"Storage Design\"  |      | [WG49 to  |
|   |                        | > Buffer Rate, Buffer |      | replace   |
|   | Set up a sequence of   | >                     |      | BDS 0 by  |
|   | Comm-B replies with    | Function]{.underline} |      | BDS       |
|   | the value of the last  | >                     |      | 0;0       |
|   | 48 bits of MB of each  | (Paragraph 3.17.3 d.) |      | .]{.mark} |
|   | reply set to the       | >                     |      |           |
|   | number of the reply in | > Set up a sequence   |      | Align     |
|   | the sequence (e.g.,    | > of Comm-B replies,  |      | ED73 with |
|   | MB=1 for first reply). | > associated with a   |      | DO181 to  |
|   | Interrogate the        | > specific BDS data   |      | include   |
|   | transponder with a     | > source designator   |      | the       |
|   | standard Comm-A,       | > code, with the      |      | repeat RR |
|   | altitude interrogation | > value of the 56 bit |      | code as   |
|   | at the rates specified | > MB field of each    |      | hi        |
|   | for long               | > reply set to a      |      | ghlighted |
|   | interrogations in      | > number to enable    |      | in        |
|   | §2.2.3.4. Verify that  | > verification of     |      | yellow.   |
|   | the replies include    | > reply sequence      |      |           |
|   | the proper data in the | > (e.g. value =2n     |      |           |
|   | MB field. [Repeat with | > where n is the      |      |           |
|   | RR equal to all valid  | > number of the reply |      |           |
|   | codes from 16 through  | > in the sequence).   |      |           |
|   | 18]{.mark}.            | >                     |      |           |
|   |                        | > Apply this sequence |      |           |
|   |                        | > of replies to the   |      |           |
|   |                        | > transponder down    |      |           |
|   |                        | > link interface at   |      |           |
|   |                        | > the rate specified  |      |           |
|   |                        | > for long            |      |           |
|   |                        | > interrogations in   |      |           |
|   |                        | > paragraph3.17.3 d.  |      |           |
|   |                        | >                     |      |           |
|   |                        | > Interrogate the     |      |           |
|   |                        | > transponder with a  |      |           |
|   |                        | > standard Comm-A,    |      |           |
|   |                        | > altitude            |      |           |
|   |                        | > interrogation       |      |           |
|   |                        | > requesting the BDS  |      |           |
|   |                        | > data source         |      |           |
|   |                        | > designator under    |      |           |
|   |                        | > test at the rate    |      |           |
|   |                        | > specified for long  |      |           |
|   |                        | > interrogations in   |      |           |
|   |                        | > paragraph 3.17.3 d. |      |           |
|   |                        | >                     |      |           |
|   |                        | > Record that the     |      |           |
|   |                        | > replies include the |      |           |
|   |                        | > correct data in the |      |           |
|   |                        | > MB field.           |      |           |
|   |                        | >                     |      |           |
|   |                        | > [Repeat for all     |      |           |
|   |                        | > valid BDS data      |      |           |
|   |                        | > source designator   |      |           |
|   |                        | > codes 0 to          |      |           |
|   |                        | > 255]{.mark}.        |      |           |
|   |                        |                       |      |           |
|   |                        | [**NOTE:** BDS code 0 |      |           |
|   |                        | represents AICB       |      |           |
|   |                        | messages. Testing of  |      |           |
|   |                        | such messages         |      |           |
|   |                        | requires such         |      |           |
|   |                        | messages to be        |      |           |
|   |                        | closed-out after      |      |           |
|   |                        | being read.]{.mark}   |      |           |
+---+------------------------+-----------------------+------+-----------+
| 3 | 2.4.2.13.3 p 178       | 5.4.12.3 p 188        | W    | SC209 and |
| 8 |                        |                       | hich | [WG49 to  |
| . | **Standard Transaction | ##### Standard        | down | exclude   |
|   | Interfaces             |  Transaction Interfac | link | bit36     |
|   | (§2.2.13.3)**          | es (Paragraph 3.17.3) | i    | from RR=  |
|   |                        |                       | nter | 17 , bit  |
|   | ...                    | ##### Test Procedure  | face | 34        |
|   |                        |                       | p    | (squitter |
|   | Step 8 Downlink        | ...                   | ort? | ]{.mark}) |
|   | Interface, Unavailable |                       |      | need to   |
|   | Data (§2.2.13.3.2.e)   | > h\. [STEP 8 ‑       |      | be tested |
|   |                        | > Downlink Interface. |      | before    |
|   | Disconnect all inputs  | > Unavailable         |      | and after |
|   | from the               | > Data]{.underline}   |      | corr      |
|   | transponder\'s         | > (Paragraph 3.17.3   |      | esponding |
|   | downlink interface     | > d.)                 |      | timer     |
|   | port. Interrogate the  | >                     |      | ex        |
|   | transponder with a     | > Disconnect all      |      | piration. |
|   | standard Comm-A,       | > inputs from the     |      |           |
|   | altitude interrogation | > transponder\'s      |      | [WG49 to  |
|   | containing RR=16.      | > downlink interface  |      | use the   |
|   | Verify that the reply  | > port.               |      | DO text   |
|   | contains all ZEROs in  | >                     |      | for       |
|   | the MB field. Repeat   | > Interrogate the     |      | RR1       |
|   | with all RR codes from | > transponder with a  |      | 8]{.mark} |
|   | 17 through 31, noting  | > standard Comm‑A,    |      |           |
|   | that:                  | > altitude            |      | Wg49 to   |
|   |                        | > interrogation       |      | add '[if  |
|   | \- For RR code 17,     | > containing RR=16.   |      | not       |
|   | bits of the MB field   | >                     |      | manage by |
|   | of the reply excluding | > Record that the     |      | the       |
|   | bits 1-8, 24, 26-32,   | > reply contains all  |      | tr        |
|   | 33 and 35 are set to   | > ZEROs in the MB     |      | ansponder |
|   | ZEROs (bits 1-8, 24,   | > field.              |      | itsel     |
|   | 26-32, 33 and 35 are   | >                     |      | f]{.mark} |
|   | or may eventually be   | > Repeat with all RR  |      | at the    |
|   | set by the transponder | > codes from 17       |      | end of RR |
|   | itself when no         | > through 31.         |      | 20-31.    |
|   | interface is           | >                     |      |           |
|   | available).            | > Verify that:        |      | Sc209 to  |
|   |                        |                       |      | consider  |
|   | [- For RR code 18, the | -   For RR code 17,   |      | addition  |
|   | reply contains all     |     bits of the MB    |      | of the    |
|   | ZEROs excluding bits 1 |     field of the      |      | last      |
|   | -- 8, in the MB field  |     reply excluding   |      | bullet.   |
|   | if the aircraft        |     bits 1-8, 24,     |      |           |
|   | identification         |     26-32, 33 and 35  |      | Completed |
|   | consists of variable   |     are set to ZEROs  |      | by SC209  |
|   | direct data, or the    |     (bits 1-8, 24,    |      |           |
|   | tail number if the     |     26-32, 33 and 35  |      |           |
|   | aircraft               |     are or may        |      |           |
|   | identification         |     eventually be set |      |           |
|   | consists of fixed      |     by the            |      |           |
|   | direct data.]{.mark}   |     transponder       |      |           |
|   |                        |     itself when no    |      |           |
|   | \- For RR code 19,     |     interface is      |      |           |
|   | bits 9-56 of the MB    |     available).       |      |           |
|   | field of the reply are |                       |      |           |
|   | set to ZEROs.          | -   [For RR code 18,  |      |           |
|   |                        |     the reply         |      |           |
|   |                        |     contains either   |      |           |
|   |                        |     all ZEROs in the  |      |           |
|   |                        |     MB field if the   |      |           |
|   |                        |     aircraft          |      |           |
|   |                        |     identification    |      |           |
|   |                        |     consists of       |      |           |
|   |                        |     variable direct   |      |           |
|   |                        |     data, or the tail |      |           |
|   |                        |     number if the     |      |           |
|   |                        |     aircraft          |      |           |
|   |                        |     identification    |      |           |
|   |                        |     consists of fixed |      |           |
|   |                        |     direct            |      |           |
|   |                        |     data.]{.mark}     |      |           |
|   |                        |                       |      |           |
|   |                        | -   For RR code 19,   |      |           |
|   |                        |     bits 9-56 of the  |      |           |
|   |                        |     MB field of the   |      |           |
|   |                        |     reply are set to  |      |           |
|   |                        |     ZEROs.            |      |           |
|   |                        |                       |      |           |
|   |                        | > \- For RR codes 20  |      |           |
|   |                        | > though 31, verify   |      |           |
|   |                        | > that the reply      |      |           |
|   |                        | > contains all ZEROs  |      |           |
|   |                        | > in the MB field.    |      |           |
+---+------------------------+-----------------------+------+-----------+

##  ELM service interfaces

+---+------------------------+-----------------------+------+-----------+
| \ | Do-181                 | ED-73                 | Com  | Proposal  |
| # |                        |                       | ment |           |
+===+========================+=======================+======+===========+
| 3 | 2.4.2.12.4 p 179       | 5.4.12.4.2 p 190      | The  | [C        |
| 9 |                        |                       | text | onsistent |
| . | **ELM Service          | **ELM Service         | in   | between   |
|   | Interfaces             | Interfaces            | ye   | DO and    |
|   | (§2.2.20.1.4 and       | (Paragraph 3.17.4)**  | llow | ED.       |
|   | §2.2.20.1.2)**         |                       | in   | Nothing   |
|   |                        | a\. [STEP 1 ‑ ELM     | DO   | to        |
|   | Step 1 ELM Uplink      | Uplink Interface,     | is   | d         |
|   | Interface, Data Rate   | Data                  | a    | o]{.mark} |
|   | (§2.2.20.1.4)          | Rate]{.underline}     | ddre |           |
|   |                        | (Paragraph 3.17.4c.)  | ssed |           |
|   | Interrogate the        |                       | in § |           |
|   | transponder with four  | > Interrogate the     | 5.   |           |
|   | 16-segment uplink ELMs | > transponder with    | 5.8. |           |
|   | (each segment having   | > four 16‑segment     | 28.2 |           |
|   | unique coding,         | > uplink ELMs (each   | in   |           |
|   | interrogations spaced  | > segment having      | ED.  |           |
|   | 50 microseconds apart, | > unique coding) with |      |           |
|   | and a new 16-segment   | > interrogations      |      |           |
|   | ELM starting 5         | > spaced 50 µs apart, |      |           |
|   | milliseconds after the | > and a new           |      |           |
|   | previous ELM). After 4 | > 16‑segment ELM      |      |           |
|   | seconds [for           | > starting each       |      |           |
|   | transponders equipped  | > second.             |      |           |
|   | for standard ELM       |                       |      |           |
|   | operation or after 1   | After 4 seconds,      |      |           |
|   | second for             | interrogate the       |      |           |
|   | transponders equipped  | transponder with      |      |           |
|   | for enhanced uplink    | another set of four   |      |           |
|   | ELM operation]{.mark}, | 16‑segment ELMs.      |      |           |
|   | interrogate the        |                       |      |           |
|   | transponder with       | > Record that correct |      |           |
|   | another set of four    | > data appear at the  |      |           |
|   | 16-segment ELMs.       | > ELM interface,      |      |           |
|   | Verify that the        | > within one second   |      |           |
|   | correct data appears   | > after completion of |      |           |
|   | at the ELM interface   | > the delivery of the |      |           |
|   | no later than one      | > corresponding       |      |           |
|   | second after           | > uplink ELM, for     |      |           |
|   | completion of the      | > both interrogation  |      |           |
|   | corresponding uplink   | > sequences.          |      |           |
|   | ELM for both           | >                     |      |           |
|   | interrogation          | > Verify that the     |      |           |
|   | sequences. Verify that | > interface reports   |      |           |
|   | the interface reports  | > an interrogator     |      |           |
|   | an interrogator        | > identifier code of  |      |           |
|   | identity code of ZERO. | > 0.                  |      |           |
|   |                        |                       |      |           |
|   | Step 2 ELM Uplink      | b\. [STEP 2 - ELM     |      |           |
|   | Interface,             | Uplink Interface,     |      |           |
|   | Interrogator           | Interrogator          |      |           |
|   | Identification         | Identi                |      |           |
|   | (§2.2.20.1.2)          | fication]{.underline} |      |           |
|   |                        | (Paragraph 3.17.4 e)  |      |           |
|   | Repeat the procedures  |                       |      |           |
|   | of Step 1 using the    | > Repeat [STEP        |      |           |
|   | multisite protocol.    | > 1]{.underline}      |      |           |
|   | Use different          | > using the multisite |      |           |
|   | Interrogator           | > protocol.           |      |           |
|   | Identifier codes and   | >                     |      |           |
|   | verify that they are   | > Use different       |      |           |
|   | correctly reported at  | > Interrogator        |      |           |
|   | the interface.         | > Identifier codes    |      |           |
|   |                        | > and verify that     |      |           |
|   | Step 3 ELM Downlink    | > they are correctly  |      |           |
|   | Interface, Data Rate   | > reported at the     |      |           |
|   | (§2.2.20.2.4 and       | > interface.          |      |           |
|   | §2.2.3.5)              |                       |      |           |
|   |                        | c\. [STEP 3 ‑ ELM     |      |           |
|   | Set up a downlink ELM  | Downlink Interface,   |      |           |
|   | which conforms to the  | Data                  |      |           |
|   | maximum capability of  | Rate]{.underline}     |      |           |
|   | the transponder (each  | (Paragraph 3.17.4 d.) |      |           |
|   | segment with unique    |                       |      |           |
|   | coding) on the Mode S  | > Set up a downlink   |      |           |
|   | transponder test set   | > ELM which conforms  |      |           |
|   | or ELM data link       | > to the maximum      |      |           |
|   | device. Interrogate    | > capability of the   |      |           |
|   | the transponder with a | > transponder (each   |      |           |
|   | Comm-C (UF=24) with    | > segment with unique |      |           |
|   | RC=3 and SRS=\"all     | > coding) on the      |      |           |
|   | ONEs.\" Verify that    | > Transponder Test    |      |           |
|   | all segments are       | > Set or ELM data     |      |           |
|   | properly transmitted   | > link device.        |      |           |
|   | 136 ±1 microseconds    | >                     |      |           |
|   | apart.                 | > Interrogate the     |      |           |
|   |                        | > transponder with a  |      |           |
|   |                        | > Comm‑C (UF=24) with |      |           |
|   |                        | > RC=3 and SRS=\"all  |      |           |
|   |                        | > ONEs\".             |      |           |
|   |                        | >                     |      |           |
|   |                        | > Check that all      |      |           |
|   |                        | > segments are        |      |           |
|   |                        | > correctly           |      |           |
|   |                        | > transmitted 136     |      |           |
|   |                        | > ±1 µs, apart.       |      |           |
+---+------------------------+-----------------------+------+-----------+

##  Sensitivity level operation

+---+------------------------+-----------------------+------+-----------+
| \ | Do-181                 | ED-73                 | Com  | Proposal  |
| # |                        |                       | ment |           |
+===+========================+=======================+======+===========+
| 4 | 2.5.4.30 p 237         | 5.5.8.34 p 235        | A    | State in  |
| 0 |                        |                       | ccor | both ED   |
| . | **Procedure #30        | ####                  | ding | and DO    |
|   | Sensitivity Level      | Procedure #30 Sensiti | to   | that b,   |
|   | Operation (§2.2.22.1.1 | vity Level Operation  | A    | c, are to |
|   | and §2.2.22.1.5)**     |                       | nnex | be        |
|   |                        | (Paragraphs 3.23.1..1 | 10   | repeated  |
|   | ...                    | and 3.23.1.5)         | vo   | with TMS  |
|   |                        |                       | lume | = 0 and   |
|   | b\. Interrogate the    | ...                   | IV § | DI =1 and |
|   | transponder with a     |                       | 4    | 7.        |
|   | UF=20 interrogation    | > b\. Interrogate the | .3.7 |           |
|   | containing a           | > transponder with a  | .3.4 | (Bob      |
|   | Sensitivity Level      | > UF=20 interrogation | it   | Saffell   |
|   | Command Message        | > containing a        | is   | to        |
|   | (ADS1=0, ADS2=5, and   | > Sensitivity Level   | only | review)   |
|   | TMS=0) with IIS=1 and  | > Command Message     | ap   |           |
|   | SLC=4.                 | > (See paragraph      | plic | Discuss   |
|   |                        | > 3.23.1.1) with      | able | the issue |
|   | Show that the IIS and  | > IIS=1 and SLC=4.    | if   | of SLC    |
|   | SLC subfields are      | >                     | TMS  | with SI   |
|   | correctly output on    | > Show that the IIS   | = 0  | code with |
|   | the transponder/TCAS   | > and SLC subfields   | and  | ICAO and  |
|   | interface.             | > are correctly       | DI   | SC209 and |
|   |                        | > output on the       | =1   | ARINC     |
|   | c\. Interrogate the    | > transponder/ACAS    | or   | c         |
|   | transponder with a     | > interface.          | 7.   | ommittee. |
|   | UF=21 interrogation    | >                     |      |           |
|   | containing a           | > c\. Interrogate the | T    | No SLC,   |
|   | Sensitivity Level      | > transponder with a  | here | with SI   |
|   | Command Message with   | > UF=21 interrogation | is a | code --   |
|   | IIS=15 and SLC=5.      | > containing a        | need | to check  |
|   |                        | > Sensitivity Level   | to   | co        |
|   | Show that the IIS and  | > Command Message     | de   | nsistency |
|   | SLC subfields are      | > with IIS=15 and     | fine |           |
|   | correctly output on    | > SLC=5.              | nega | EP to     |
|   | the transponder/TCAS   | >                     | tive | raise the |
|   | interface.             | > Show that the IIS   | te   | issue to  |
|   |                        | > and SLC subfields   | sts. | TSG       |
|   |                        | > are correctly       |      | before    |
|   |                        | > output on the       | Cla  | next      |
|   |                        | > transponder/ACAS    | rify | meeting.  |
|   |                        | > interface.          | whe  |           |
|   |                        | >                     | ther |           |
|   |                        | > d\. Interrogate the | the  |           |
|   |                        | > transponder with a  | test |           |
|   |                        | > UF=20 interrogation | are  |           |
|   |                        | > containing a        | to   |           |
|   |                        | > Sensitivity Level   | be   |           |
|   |                        | > Command Message     | def  |           |
|   |                        | > with SIS=1 and      | ined |           |
|   |                        | > SLC=4.              | for  |           |
|   |                        | >                     | SI   |           |
|   |                        | > Show that the SIS   | code |           |
|   |                        | > and SLC subfields   | cap  |           |
|   |                        | > are correctly       | able |           |
|   |                        | > output on the       | tran |           |
|   |                        | > transponder/ACAS    | spon |           |
|   |                        | > interface.          | ders |           |
|   |                        | >                     | (    |           |
|   |                        | > e\. Interrogate the | i.e. |           |
|   |                        | > transponder with a  | c    |           |
|   |                        | > UF=21 interrogation | orre |           |
|   |                        | > containing a        | spon |           |
|   |                        | > Sensitivity Level   | ding |           |
|   |                        | > Command Message     | to   |           |
|   |                        | > with SIS=63 and     | s    |           |
|   |                        | > SLC=5.              | teps |           |
|   |                        | >                     | d    |           |
|   |                        | > Show that the SIS   | and  |           |
|   |                        | > and SLC subfields   | e in |           |
|   |                        | > are correctly       | ED). |           |
|   |                        | > output on the       |      |           |
|   |                        | > transponder/ACAS    | The  |           |
|   |                        | > interface.          | in   |           |
|   |                        |                       | terr |           |
|   |                        |                       | ogat |           |
|   |                        |                       | ions |           |
|   |                        |                       | c    |           |
|   |                        |                       | orre |           |
|   |                        |                       | spon |           |
|   |                        |                       | ding |           |
|   |                        |                       | to   |           |
|   |                        |                       | test |           |
|   |                        |                       | d    |           |
|   |                        |                       | and  |           |
|   |                        |                       | e    |           |
|   |                        |                       | are  |           |
|   |                        |                       | not  |           |
|   |                        |                       | poss |           |
|   |                        |                       | ible |           |
|   |                        |                       | a    |           |
|   |                        |                       | ccor |           |
|   |                        |                       | ding |           |
|   |                        |                       | to   |           |
|   |                        |                       | A    |           |
|   |                        |                       | nnex |           |
|   |                        |                       | 10   |           |
|   |                        |                       | vol  |           |
|   |                        |                       | IV,  |           |
|   |                        |                       | when |           |
|   |                        |                       | DI = |           |
|   |                        |                       | 1 or |           |
|   |                        |                       | 7    |           |
|   |                        |                       | t    |           |
|   |                        |                       | here |           |
|   |                        |                       | is   |           |
|   |                        |                       | no   |           |
|   |                        |                       | SIS  |           |
|   |                        |                       | f    |           |
|   |                        |                       | ield |           |
|   |                        |                       | in   |           |
|   |                        |                       | SD.  |           |
+---+------------------------+-----------------------+------+-----------+

##  MU message

+---+------------------------+-----------------------+------+-----------+
| \ | Do-181                 | ED-73                 | Com  | Proposal  |
| # |                        |                       | ment |           |
+===+========================+=======================+======+===========+
| 4 | 2.2.22.1.3 p 118       | 3.23.1.3 p 103        |      | [wG49 to  |
| 1 |                        |                       |      | add note  |
| . | **MU Message, Comm-U   | #### MU Message       |      | 2         |
|   | Used by TCAS**         | , Comm‑U used by ACAS |      | (yellow)  |
|   |                        |                       |      | in        |
|   | The Mode S transponder | The Mode S            |      | E         |
|   | **shall** supply the   | transponder shall     |      | D]{.mark} |
|   | MU field (see          | supply the MU field   |      |           |
|   | §2.2.14.4.25) of a     | (paragraph 3.18.4.22) |      |           |
|   | long special           | of a long air-air     |      |           |
|   | surveillance           | surveillance          |      |           |
|   | interrogation, UF=16,  | interrogation, UF=16, |      |           |
|   | to TCAS only under the | to ACAS.              |      |           |
|   | following conditions:  |                       |      |           |
|   |                        | **NOTE:** The MU      |      |           |
|   | a\. The interrogation  | field is used by ACAS |      |           |
|   | contains the           | to transmit a ACAS    |      |           |
|   | transponder's discrete | Broadcast             |      |           |
|   | address and UDS=48.    | Interrogation Message |      |           |
|   |                        | containing own        |      |           |
|   | b\. The interrogation  | transponders\'s       |      |           |
|   | contains the broadcast | address for the       |      |           |
|   | address (all ONES) and | purpose of            |      |           |
|   | UDS=50                 | controlling           |      |           |
|   |                        | interference caused   |      |           |
|   | ***Notes:***           | by ACAS               |      |           |
|   |                        | interrogations, or to |      |           |
|   | *1. The MU field is    | transmit a ACAS       |      |           |
|   | used by TCAS to        | Resolution Message    |      |           |
|   | transmit a TCAS        | for air‑to‑air        |      |           |
|   | Broadcast              | resolution advisory   |      |           |
|   | Interrogation Message  | coordination.         |      |           |
|   | containing own         |                       |      |           |
|   | transponder\'s address | Subfield in MU for a  |      |           |
|   | for the purpose of     | ACAS Resolution       |      |           |
|   | controlling            | Message               |      |           |
|   | interference caused by |                       |      |           |
|   | TCAS interrogations,   |   ------ --           |      |           |
|   | or to transmit a TCAS  | --------------------- |      |           |
|   | Resolution Message for |                       |      |           |
|   | air-to-air resolution  |  UDS:   [U‑Definition |      |           |
|   | advisory               |          Su           |      |           |
|   | coordination.*         | bfield]{.underline} ‑ |      |           |
|   |                        |                       |      |           |
|   | *[2. Ideally the       |    This 8‑bit (33‑40) |      |           |
|   | transponder should     |                       |      |           |
|   | serve as a modem for   |  subfield defines the |      |           |
|   | TCAS and supply the    |          da           |      |           |
|   | entire MU field to     | ta content and coding |      |           |
|   | TCAS (including the    |          in           |      |           |
|   | UDS Field) of any      |  the remainder of the |      |           |
|   | received UF=16         |                       |      |           |
|   | interrogation.         |         MU field. For |      |           |
|   | Currently implemented  |          c            |      |           |
|   | transponder/TCAS       | onvenience in coding, |      |           |
|   | interface protocols do |          UD           |      |           |
|   | not provide the UDS    | S is expressed in two |      |           |
|   | Field information to   |          g            |      |           |
|   | TCAS so it is          | roups of 4 bits each; |      |           |
|   | necessary for these    |                       |      |           |
|   | transponders to select |    UDS1, (33-36), and |      |           |
|   | the UDS messages that  |                       |      |           |
|   | are passed to TCAS. If |   UDS2, (37-40). ACAS |      |           |
|   | this interface         |                       |      |           |
|   | limitation is removed  |   Resolution Messages |      |           |
|   | in the future, then    |          s            |      |           |
|   | all UDS messages would | hall be identified by |      |           |
|   | be passed to           |          U            |      |           |
|   | TCAS.]{.mark}*         | DS1=3 and UDS2=0, the |      |           |
|   |                        |          co           |      |           |
|   | Subfield in MU for a   | mbination of which is |      |           |
|   | TCAS Resolution        |                       |      |           |
|   | Message                | equivalent to UDS=48. |      |           |
|   |                        |                       |      |           |
|   | UDS: U-Definition      |   ------ --           |      |           |
|   | Subfield -- This 8-bit | --------------------- |      |           |
|   | (33-40) subfield       |                       |      |           |
|   | defines the data       | Subfield in MU for a  |      |           |
|   | content and coding in  | ACAS Broadcast        |      |           |
|   | the remainder of the   | Message               |      |           |
|   | MU field. For          |                       |      |           |
|   | convenience in coding, |   ------ --           |      |           |
|   | UDS is expressed in    | --------------------- |      |           |
|   | two groups of 4 bits   |                       |      |           |
|   | each; UDS1, 33 through |  UDS:   [U‑Definition |      |           |
|   | 36, and UDS2, 37       |          Su           |      |           |
|   | through 40. TCAS       | bfield]{.underline} ‑ |      |           |
|   | Resolution Messages    |                       |      |           |
|   | **shall** be           |      A ACAS Broadcast |      |           |
|   | identified by UDS1=3   |                       |      |           |
|   | and                    | Interrogation Message |      |           |
|   |                        |          is           |      |           |
|   | UDS2=0, the            |  identified by UDS1=3 |      |           |
|   | combination of which   |                       |      |           |
|   | is equivalent to       |       and UDS2=2, the |      |           |
|   | UDS=48.                |          co           |      |           |
|   |                        | mbination of which is |      |           |
|   | Subfield in MU for a   |                       |      |           |
|   | TCAS Broadcast Message | equivalent to UDS=50. |      |           |
|   |                        |                       |      |           |
|   | UDS: U-Definition      |   ------ --           |      |           |
|   | Subfield -- A TCAS     | --------------------- |      |           |
|   | Broadcast              |                       |      |           |
|   | Interrogation Message  |                       |      |           |
|   | is identified by       |                       |      |           |
|   | UDS1=3 and UDS2=2, the |                       |      |           |
|   | combination of which   |                       |      |           |
|   | is equivalent to       |                       |      |           |
|   | UDS=50.                |                       |      |           |
+---+------------------------+-----------------------+------+-----------+
| 4 | 2.5.4.35 p 247/248     | 5.5.8.39 p 243        |      | To be     |
| 2 |                        |                       |      | discuss   |
| . | **Procedure #35 MU     | #### Procedure #35 AC |      | whether   |
|   | Messages To TCAS       | AS Broadcast Message  |      | ED is to  |
|   | (§2.2.22.1.3)**        |                       |      | be        |
|   |                        | (Paragraph 3.23.1.3)  |      | aligned   |
|   | This test verifies     |                       |      | on DO.    |
|   | that the transponder   | This test verifies    |      |           |
|   | correctly: 1) accepts  | that the transponder  |      | RM to     |
|   | UF=16 interrogations   | accepts incoming      |      | check the |
|   | with MU data           | UF=16 interrogations  |      | text and  |
|   | containing a TCAS      | containing an ACAS    |      | confirm   |
|   | Resolution Message     | Broadcast Message and |      | whether   |
|   | (UDS=48) and passes    | passes all necessary  |      | the DO    |
|   | all necessary          | information to the    |      | text can  |
|   | information to the     | ACAS unit.            |      | be        |
|   | TCAS unit; 2) accepts  |                       |      | re-used   |
|   | UF=16 broadcast        | In one second,        |      | in ED.    |
|   | interrogations with MU | interrogate the       |      |           |
|   | data containing a TCAS | transponder with ten  |      | [RM is    |
|   | Broadcast Message      | UF=16 interrogations, |      | working   |
|   | (UDS=50) and passes    | each containing an    |      | on this   |
|   | all necessary          | ACAS Broadcast        |      | an        |
|   | information to the     | Message (UDS1=3,      |      | d]{.mark} |
|   | TCAS unit; 3) does not | UDS2=2, and           |      | [it will  |
|   | transfer the MU data   | interrogation         |      | b         |
|   | of UF=16 discrete      | address=all 1\'s),    |      | e]{.mark} |
|   | interrogations with    | each containing a     |      | [         |
|   | UDS≠48 and broadcast   | unique \"own\" Mode S |      | available |
|   | interrogations with    | address (i.e., ten    |      | for the   |
|   | UDS≠50 to the TCAS     | different Mode S      |      | September |
|   | unit.                  | addresses).           |      | meetin    |
|   |                        |                       |      | g]{.mark} |
|   | a\. Interrogate the    | Show that incoming    |      | [Complete |
|   | transponder with a     | information is        |      | d]{.mark} |
|   | valid UF=16 TCAS       | correctly output on   |      |           |
|   | Coordination Message   | the transponder/ACAS  |      |           |
|   | (UDS1=3, UDS2=0).      | interface.            |      |           |
|   | Verify that the        |                       |      |           |
|   | transponder replies    |                       |      |           |
|   | with a valid DF=16     |                       |      |           |
|   | Coordination Reply     |                       |      |           |
|   | Message and the data   |                       |      |           |
|   | content of the MU      |                       |      |           |
|   | field is correctly     |                       |      |           |
|   | output on the          |                       |      |           |
|   | transponder/TCAS       |                       |      |           |
|   | interface.             |                       |      |           |
|   |                        |                       |      |           |
|   | b\. In one second,     |                       |      |           |
|   | interrogate the        |                       |      |           |
|   | transponder with ten   |                       |      |           |
|   | UF=16 interrogations,  |                       |      |           |
|   | each containing a TCAS |                       |      |           |
|   | Broadcast Message      |                       |      |           |
|   | (UDS1=3, UDS2=2, and   |                       |      |           |
|   | interrogation address  |                       |      |           |
|   | all ONEs), each        |                       |      |           |
|   | containing a unique    |                       |      |           |
|   | "own" Mode S address   |                       |      |           |
|   | (i.e., ten different   |                       |      |           |
|   | Mode S addresses).     |                       |      |           |
|   | Verify that the MU     |                       |      |           |
|   | data for each          |                       |      |           |
|   | interrogation is       |                       |      |           |
|   | correctly output on    |                       |      |           |
|   | the transponder/TCAS   |                       |      |           |
|   | interface.             |                       |      |           |
|   |                        |                       |      |           |
|   | c\. Interrogate the    |                       |      |           |
|   | transponder at the     |                       |      |           |
|   | rate of 10 per second  |                       |      |           |
|   | or less with 255 UF=16 |                       |      |           |
|   | interrogations         |                       |      |           |
|   | addressed to the       |                       |      |           |
|   | transponder with UDS   |                       |      |           |
|   | values from 0 to 255   |                       |      |           |
|   | except for UDS=48.     |                       |      |           |
|   | Verify that the        |                       |      |           |
|   | transponder does not   |                       |      |           |
|   | output the messages    |                       |      |           |
|   | over the               |                       |      |           |
|   | transponder/TCAS       |                       |      |           |
|   | interface.             |                       |      |           |
|   |                        |                       |      |           |
|   | d\. Interrogate the    |                       |      |           |
|   | transponder at the     |                       |      |           |
|   | rate of 10 per second  |                       |      |           |
|   | or less with 255 UF=16 |                       |      |           |
|   | broadcast              |                       |      |           |
|   | interrogations with    |                       |      |           |
|   | UDS values from 0 to   |                       |      |           |
|   | 255 except for UDS=50. |                       |      |           |
|   | Verify that the        |                       |      |           |
|   | transponder does not   |                       |      |           |
|   | output the messages    |                       |      |           |
|   | over the               |                       |      |           |
|   | transponder/TCAS       |                       |      |           |
|   | interface.             |                       |      |           |
+---+------------------------+-----------------------+------+-----------+

##  Non selective lockout

+---+-------------------------+----------------------+------+-----------+
| \ | Do-181                  | ED-73                | Com  | Proposal  |
| # |                         |                      | ment |           |
+===+=========================+======================+======+===========+
| 4 | 2.5.4.4.2 p 189         | 5.5.8.4 p 199/200    |      | [WG49 to  |
| 3 |                         |                      |      | align ED  |
| . | **Required Negative     | **Procedure #4 -     |      | on        |
|   | Tests**                 | Non-Selective        |      | D         |
|   |                         | Lockout Tests        |      | O]{.mark} |
|   | a\. PC Discrimination   | (Paragraph           |      |           |
|   |                         | 3.20.2.4)**          |      |           |
|   | The interrogation       |                      |      |           |
|   | patterns are:           | b\. Required         |      |           |
|   |                         | Negative Tests       |      |           |
|   | UF = 4, 5, 20, 21.      |                      |      |           |
|   |                         | \(1\) PC             |      |           |
|   | PC = 0 and DI≠3,        | Discrimination       |      |           |
|   |                         |                      |      |           |
|   | PC = 0 and DI=3 and     | > The interrogation  |      |           |
|   | LSS=1 and SIS=0,        | > patterns are:      |      |           |
|   |                         | >                    |      |           |
|   | PC = 1 and DI=3,        | > UF = 4, 5, 20, 21. |      |           |
|   |                         | >                    |      |           |
|   | PC = 2, 3, 4, 5, 6. 7.  | > PC = 0, 2, 3, 4,   |      |           |
|   |                         | > 5, 6, 7.           |      |           |
|   | Total number of         | >                    |      |           |
|   | patterns = 36.          | > Total number of    |      |           |
|   |                         | > patterns = 28.     |      |           |
|   | With the transponder    | >                    |      |           |
|   | not in non-selective    | > With the           |      |           |
|   | lockout state,          | > transponder not in |      |           |
|   | interrogate with all of | > non-selective      |      |           |
|   | the above patterns      | > lockout state,     |      |           |
|   | consecutively. Verify   | > interrogate with   |      |           |
|   | that, after the         | > all of the above   |      |           |
|   | sequence, the           | > patterns           |      |           |
|   | non-selective lockout   | > consecutively.     |      |           |
|   | state does not exist.   | > Verify that the    |      |           |
|   |                         | > non-selective      |      |           |
|   |                         | > lockout state      |      |           |
|   |                         | > never exists       |      |           |
|   |                         | > during this test   |      |           |
|   |                         | > sequence.          |      |           |
+---+-------------------------+----------------------+------+-----------+
| 4 | 2.5.4.5 p 191           | 5.5.8.5 p 201        | Cla  | EP check  |
| 4 |                         |                      | rify | with ICAO |
| . | **Procedure #5          | **Procedure #5       | if   | SI code   |
|   | Selective Lockout       | Selective Lockout    | l    | on level  |
|   | Tests**                 | Tests (Paragraph     | evel | 1         |
|   |                         | 3.20.2.5)**          | 1    | tra       |
|   | Pattern Definition for  |                      | tra  | nsponder. |
|   | Level 1 Transponders    | 5.5.8.5.1 Pattern    | nspo | (SI code  |
|   |                         | Definition           | nder | possible  |
|   | ...                     |                      | can  | with      |
|   |                         | > a\. Level 1        | be   | level 1   |
|   | Total Interrogation     | > Transponders       | SI   | tra       |
|   | Patterns Per Timer      |                      | capa | nsponder) |
|   |                         | ...                  | ble, |           |
|   | UF: 2 codes.            |                      | if   | WG49 and  |
|   |                         | > Total              | not  | SC209 to  |
|   | DI: 2 codes with        | > Interrogation      | a    | agree the |
|   | LOS=0,1; 1 code with    | > Patterns per Timer | modi | negative  |
|   | LSS=0, 1                | >                    | fica | test      |
|   |                         | > UF: 4, 5 (2        | tion | patterns  |
|   | 5 codes with SD field   | > codes).            | in   |           |
|   | bits 23 & 26 = 1        | >                    | A    | Working   |
|   |                         | > DI:                | nnex | paper     |
|   | Total: 20 possible      | > 0,1,2,3,4,5,6,7 (8 | 10   | SC20      |
|   | patterns for II timers, | > codes).            | vol  | 9-WP05-07 |
|   | 18 possible patterns    | >                    | IV   | discusses |
|   | for SI timers.          | > LOS: 0, 1 (2       | is   |           |
|   |                         | > codes).            | nee  | Correct   |
|   | Positive test patterns: | >                    | ded. | total     |
|   | 2 or 4.                 | > LSS: 0, 1 (2       |      | number of |
|   |                         | > codes).            | It   | test      |
|   | Negative test patterns: | >                    | s    | should be |
|   | 16.                     | > Positive test      | eems | 128 = 6 + |
|   |                         | > patterns: 6.       | that | 122       |
|   |                         | >                    | some | (         |
|   |                         | > Negative test      | less | according |
|   |                         | > patterns: 58.      | cred | to the    |
|   |                         | >                    | ible | test      |
|   |                         | > Total: 64 possible | nega | p         |
|   |                         | > patterns per       | tive | rocedure) |
|   |                         | > timer.             | t    | if II +   |
|   |                         |                      | ests | SI code   |
|   |                         |                      | are  | but this  |
|   |                         |                      | not  | is only   |
|   |                         |                      | incl | for one   |
|   |                         |                      | uded | code. It  |
|   |                         |                      | in   | shall be  |
|   |                         |                      | DO,  | repeated  |
|   |                         |                      | whe  | for all   |
|   |                         |                      | reas | possible  |
|   |                         |                      | the  | II and SI |
|   |                         |                      | ED   | codes.    |
|   |                         |                      | app  |           |
|   |                         |                      | lies |           |
|   |                         |                      | a    |           |
|   |                         |                      | sy   |           |
|   |                         |                      | stem |           |
|   |                         |                      | atic |           |
|   |                         |                      | po   |           |
|   |                         |                      | licy |           |
|   |                         |                      | all  |           |
|   |                         |                      | the  |           |
|   |                         |                      | comb |           |
|   |                         |                      | inat |           |
|   |                         |                      | ions |           |
|   |                         |                      | w    |           |
|   |                         |                      | hich |           |
|   |                         |                      | does |           |
|   |                         |                      | not  |           |
|   |                         |                      | co   |           |
|   |                         |                      | rres |           |
|   |                         |                      | pond |           |
|   |                         |                      | to a |           |
|   |                         |                      | posi |           |
|   |                         |                      | tive |           |
|   |                         |                      | test |           |
|   |                         |                      | s    |           |
|   |                         |                      | hall |           |
|   |                         |                      | be   |           |
|   |                         |                      | te   |           |
|   |                         |                      | sted |           |
|   |                         |                      | as a |           |
|   |                         |                      | nega |           |
|   |                         |                      | tive |           |
|   |                         |                      | t    |           |
|   |                         |                      | est. |           |
+---+-------------------------+----------------------+------+-----------+
| 4 | 2.5.4.5 p 191           | 5.5.8.5 p 201        | It   | Same as   |
| 5 |                         |                      | s    | S44       |
| . | **Procedure #5          | **Procedure #5       | eems |           |
|   | Selective Lockout       | Selective Lockout    | that | Replace   |
|   | Tests**                 | Tests (Paragraph     | some | in ED the |
|   |                         | 3.20.2.5)**          | less | line LSS: |
|   | ...                     |                      | cred | 1 (1      |
|   |                         | 5.5.8.5.1 Pattern    | ible | code)     |
|   | Pattern Definition of   | Definition           | nega | with the  |
|   | All Other Transponder   |                      | tive | 2         |
|   | Designs                 | ...                  | t    | following |
|   |                         |                      | ests | lines:    |
|   | ...                     | > b\. Pattern        | are  |           |
|   |                         | > Definition of All  | not  | > LOS: 0, |
|   | Total Interrogation     | > Other Transponder  | incl | > 1 (2    |
|   | Patterns Per Timer      | > Designs            | uded | > codes). |
|   |                         | >                    | in   | >         |
|   | UF: 4 codes.            | > The patterns below | DO,  | > LSS: 0, |
|   |                         | > are a list of      | whe  | > 1 (2    |
|   | DI: 2 codes with LOS=   | > possible patterns  | reas | > codes). |
|   | 0,1; 1 code with        | > that can be used   | the  |           |
|   | LSS=0,1;                | > to run the tests   | ED   | Correct   |
|   |                         | > in this procedure  | app  | total     |
|   | 5 codes with SD field   | > for Level 2        | lies | number of |
|   | bits 23 & 26 = 1        | > Transponders and   | a    | test      |
|   |                         | > above.             | sy   | should be |
|   | Total: 40 possible      | >                    | stem | 256 =     |
|   | patterns for II timers, | > ...                | atic | 12 + 244  |
|   | 36 possible patterns    | >                    | po   | (         |
|   | for SI timers.          | > Total              | licy | according |
|   |                         | > Interrogation      | all  | to the    |
|   | Positive test patterns: | > Patterns per Timer | the  | test      |
|   | 4 or 8.                 | >                    | comb | p         |
|   |                         | > UF: 4, 5, 20, 21   | inat | rocedure) |
|   | Negative test pattern:  | > (4 codes).         | ions | but this  |
|   | 32.                     | >                    | w    | is only   |
|   |                         | > DI:                | hich | for one   |
|   | ***Note:** The 8        | > 0,1,2,3,4,5,6,7 (8 | does | code. It  |
|   | negative test patterns  | > codes).            | not  | shall be  |
|   | per UF code are as      | >                    | co   | repeated  |
|   | follows: For each value | > LSS: 1 (1 code).   | rres | for all   |
|   | of DI (0 -- 7) set the  | >                    | pond | possible  |
|   | IIS or SIS code         | > Positive test      | to a | II and SI |
|   | correctly. For DI code  | > patterns: 12.      | posi | codes.    |
|   | values where there is   | >                    | tive |           |
|   | no IIS or SIS subfield  | > Negative test      | test | Working   |
|   | within the SD field,    | > patterns: 116      | s    | paper     |
|   | set the corresponding   | >                    | hall | SC20      |
|   | bits (bits 17-20 for    | > Total: 128         | be   | 9-WP05-07 |
|   | IIS or 17-22 for SIS).  | > patterns.          | te   | discusses |
|   | If DI=1 or 7, set       |                      | sted |           |
|   | LOS=0, for all other    |                      | as a |           |
|   | values of DI, set bit   |                      | nega |           |
|   | 26=1. If DI=3, set      |                      | tive |           |
|   | LSS=0, for all other    |                      | t    |           |
|   | values of DI, set bit   |                      | est. |           |
|   | 23=1.*                  |                      |      |           |
+---+-------------------------+----------------------+------+-----------+
| 4 | 2.5.4.5 p 192           | 5.5.8.5 p 202/203    | The  | DO and ED |
| 6 |                         |                      | po   | shall     |
| . | **Procedure #5          | **Procedure #5       | licy | specify   |
|   | Selective Lockout       | Selective Lockout    | for  | that the  |
|   | Tests**                 | Tests (Paragraph     | nega | procedure |
|   |                         | 3.20.2.5)**          | tive | is        |
|   | ...                     |                      | test | repeated  |
|   |                         | ...                  | in   | for each  |
|   | Principle of Test       |                      | DO   | type UF   |
|   | Sequence                | ##                   | and  | and each  |
|   |                         | ### 5.5.8.5.3 Princi | ED   | possible  |
|   | ...                     | ple of Test Sequence | is   | II and SI |
|   |                         |                      | d    | codes.    |
|   | Test #1 Multisite, TL   | ...                  | iffe |           |
|   | Timer and Lockout:      |                      | rent | In the    |
|   | Timer Duration and      | a\. Test #1 -        | w    | last step |
|   | Insensitivity to        | Multisite, TL Timer  | hich | of the DO |
|   | Non-Valid Signals (All  | and Lockout: Timer   | is   | it is     |
|   | Transponders)           | Duration and         | ex   | proposed  |
|   |                         | Insensitivity to     | plai | to add "  |
|   | ![]                     | Non-Valid Signals    | ning | with UF   |
|   | (media/image8.wmf){widt | (All Transponders)   | the  | 11" to be |
|   | h="3.953472222222222in" |                      | dif  | c         |
|   | height=                 | > \(1\) run test for | fere | onsistent |
|   | "1.9715277777777778in"} | > each IIS related   | nces | with      |
|   |                         | > TL timer           | in   | previous  |
|   | If the last test fails, |                      | the  | step and  |
|   | the timer either runs   |   ------------------ | pr   | to be     |
|   | too long or has been    | -- ----------------- | oced | c         |
|   | restarted by a          |   [Time]{            | ure. | onsistent |
|   | non-valid signal.       | .underline}   Action |      | with ED.  |
|   |                         |   (                  |      |           |
|   | ***Note:** Test #1      | sec)                 |      | Same test |
|   | provides the basic      |                      |      | in        |
|   | timing of a test        |                      |      | principle |
|   | sequence that satisfies |                      |      | but more  |
|   | the principles of the   |                      |      | detailed  |
|   | test procedure while    |   0.00               |      | in ED     |
|   | maintaining a maximum   |     Start timer with |      |           |
|   | of 50 interrogations    |                      |      | WG49 to   |
|   | per second. Because the |     UF=4, DI= 1, LOS |      | justify   |
|   | test sequence calls for |                      |      | why       |
|   | interlacing multisite   |                  = 1 |      | a         |
|   | lockout timers (in this |                      |      | dditional |
|   | case one is started     |   0.02               |      | details   |
|   | every 2 seconds), the   |    Verify lockout to |      | were      |
|   | above sequence will     |                      |      | added     |
|   | need to accommodate the |     timer\'s II with |      |           |
|   | critical timer          |                      |      | SC209 to  |
|   | verifications that      |               UF=11. |      | consider  |
|   | occur at 16.9 and 19.1  |                      |      | addition  |
|   | seconds relative to the |   0.04 to            |      | of UF 11  |
|   | start of each timer.    |  9.90         Verify |      | in the    |
|   | When the test sequence  |                      |      | last step |
|   | reaches 16.9 and 19.1   |       non-lockout to |      |           |
|   | seconds after the start |                      |      | Working   |
|   | of each timer it will   |    all other IIS and |      | paper     |
|   | be 0.9 and 1.1 after    |                      |      | SC20      |
|   | the start of a new      |                 SIS. |      | 9-WP05-07 |
|   | timer. Priority is      |                      |      | discusses |
|   | given to verify the     |   10.0               |      |           |
|   | lockout of the earlier  |    Try timer restart |      |           |
|   | timer at the correct    |                      |      |           |
|   | time, while the         |     with correct IIS |      |           |
|   | verification of         |                      |      |           |
|   | non-lockout to all      |        and incorrect |      |           |
|   | other timers is         |                      |      |           |
|   | scheduled around these  |             DI - LOS |      |           |
|   | critical measurements.* |                      |      |           |
|   |                         |    combinations (DI= |      |           |
|   |                         |                      |      |           |
|   |                         |     0, 2, 3, 4, 5, 6 |      |           |
|   |                         |                      |      |           |
|   |                         |           and Bit 26 |      |           |
|   |                         |                      |      |           |
|   |                         |         (location of |      |           |
|   |                         |                      |      |           |
|   |                         |    LOS)=0,1; DI = 1, |      |           |
|   |                         |                      |      |           |
|   |                         |    7 and LOS = 0 (14 |      |           |
|   |                         |                      |      |           |
|   |                         |       combinations)) |      |           |
|   |                         |                      |      |           |
|   |                         |   13.3               |      |           |
|   |                         |    Try timer restart |      |           |
|   |                         |                      |      |           |
|   |                         |     with correct IIS |      |           |
|   |                         |                      |      |           |
|   |                         |       and all DI-LSS |      |           |
|   |                         |                      |      |           |
|   |                         |         combinations |      |           |
|   |                         |                      |      |           |
|   |                         |      (DI=0, 1, 2, 3, |      |           |
|   |                         |                      |      |           |
|   |                         |       4, 5, 6, 7 and |      |           |
|   |                         |                      |      |           |
|   |                         |     Bit 23 (location |      |           |
|   |                         |                      |      |           |
|   |                         |      of LSS)=0,1 (16 |      |           |
|   |                         |                      |      |           |
|   |                         |      combinations)). |      |           |
|   |                         |                      |      |           |
|   |                         |   16.9               |      |           |
|   |                         |    Verify lockout to |      |           |
|   |                         |                      |      |           |
|   |                         |     timer\'s II with |      |           |
|   |                         |                      |      |           |
|   |                         |               UF=11. |      |           |
|   |                         |                      |      |           |
|   |                         |   19.1               |      |           |
|   |                         |               Verify |      |           |
|   |                         |                      |      |           |
|   |                         |     non-lockout with |      |           |
|   |                         |                      |      |           |
|   |                         |               UF=11. |      |           |
|   |                         |   ------------------ |      |           |
|   |                         | -- ----------------- |      |           |
|   |                         |                      |      |           |
|   |                         | > If the last test   |      |           |
|   |                         | > fails, the timer   |      |           |
|   |                         | > either runs too    |      |           |
|   |                         | > long or has been   |      |           |
|   |                         | > restarted by a     |      |           |
|   |                         | > non-valid signal.  |      |           |
|   |                         | >                    |      |           |
|   |                         | > \(2\) run test for |      |           |
|   |                         | > each SIS related   |      |           |
|   |                         | > TL timer           |      |           |
|   |                         |                      |      |           |
|   |                         |   ------------------ |      |           |
|   |                         | -- ----------------- |      |           |
|   |                         |   [Time]{            |      |           |
|   |                         | .underline}   Action |      |           |
|   |                         |   (                  |      |           |
|   |                         | sec)                 |      |           |
|   |                         |                      |      |           |
|   |                         |                      |      |           |
|   |                         |                      |      |           |
|   |                         |                      |      |           |
|   |                         |   0.00               |      |           |
|   |                         |     Start timer with |      |           |
|   |                         |                      |      |           |
|   |                         |    UF=4, DI = 3, LSS |      |           |
|   |                         |                      |      |           |
|   |                         |                  =1. |      |           |
|   |                         |                      |      |           |
|   |                         |   0.02               |      |           |
|   |                         |    Verify lockout to |      |           |
|   |                         |                      |      |           |
|   |                         |     timer\'s SI with |      |           |
|   |                         |                      |      |           |
|   |                         |               UF=11. |      |           |
|   |                         |                      |      |           |
|   |                         |   0.04 to            |      |           |
|   |                         |  9.90         Verify |      |           |
|   |                         |                      |      |           |
|   |                         |       non-lockout to |      |           |
|   |                         |                      |      |           |
|   |                         |    all other IIS and |      |           |
|   |                         |                      |      |           |
|   |                         |                 SIS. |      |           |
|   |                         |                      |      |           |
|   |                         |   10.0               |      |           |
|   |                         |    Try timer restart |      |           |
|   |                         |                      |      |           |
|   |                         |     with correct SIS |      |           |
|   |                         |                      |      |           |
|   |                         |       and all DI-LOS |      |           |
|   |                         |                      |      |           |
|   |                         |         combinations |      |           |
|   |                         |                      |      |           |
|   |                         |      (DI=0, 1, 2, 3, |      |           |
|   |                         |                      |      |           |
|   |                         |       4, 5, 6, 7 and |      |           |
|   |                         |                      |      |           |
|   |                         |     Bit 26 (location |      |           |
|   |                         |                      |      |           |
|   |                         |      of LOS)=0,1 (16 |      |           |
|   |                         |                      |      |           |
|   |                         |       combinations)) |      |           |
|   |                         |                      |      |           |
|   |                         |   13.3               |      |           |
|   |                         |    Try timer restart |      |           |
|   |                         |                      |      |           |
|   |                         |     with correct SIS |      |           |
|   |                         |                      |      |           |
|   |                         |        and incorrect |      |           |
|   |                         |                      |      |           |
|   |                         |               DI-LSS |      |           |
|   |                         |                      |      |           |
|   |                         |         combinations |      |           |
|   |                         |                      |      |           |
|   |                         |      (DI=0, 1, 2, 4, |      |           |
|   |                         |                      |      |           |
|   |                         |          5, 6, 7 and |      |           |
|   |                         |                      |      |           |
|   |                         |    LSS=0,1; DI=3 and |      |           |
|   |                         |                      |      |           |
|   |                         |     Bit 23 (location |      |           |
|   |                         |                      |      |           |
|   |                         |      of LSS) = 0 (15 |      |           |
|   |                         |                      |      |           |
|   |                         |      combinations)). |      |           |
|   |                         |                      |      |           |
|   |                         |   16.9               |      |           |
|   |                         |    Verify lockout to |      |           |
|   |                         |                      |      |           |
|   |                         |     timer\'s SI with |      |           |
|   |                         |                      |      |           |
|   |                         |               UF=11. |      |           |
|   |                         |                      |      |           |
|   |                         |   19.1               |      |           |
|   |                         |               Verify |      |           |
|   |                         |                      |      |           |
|   |                         |     non-lockout with |      |           |
|   |                         |                      |      |           |
|   |                         |               UF=11. |      |           |
|   |                         |   ------------------ |      |           |
|   |                         | -- ----------------- |      |           |
|   |                         |                      |      |           |
|   |                         | > If the last test   |      |           |
|   |                         | > fails, the timer   |      |           |
|   |                         | > either runs too    |      |           |
|   |                         | > long or has been   |      |           |
|   |                         | > restarted by a     |      |           |
|   |                         | > non-valid signal.  |      |           |
+---+-------------------------+----------------------+------+-----------+
| 4 | 2.5.4.5 p 193           | 5.5.8.5 p 202/203    | ED   | SC-209 :  |
| 7 |                         |                      | test | should    |
| . | **Procedure #5          | **Procedure #5       | are  | consider  |
|   | Selective Lockout       | Selective Lockout    | more | to use    |
|   | Tests**                 | Tests (Paragraph     | deta | the       |
|   |                         | 3.20.2.5)**          | iled | Eurocae   |
|   | ...                     |                      | and  | test      |
|   |                         | ...                  | cle  | p         |
|   | Principle of Test       |                      | arly | rocedures |
|   | Sequence                | ##                   | det  |           |
|   |                         | ### 5.5.8.5.3 Princi | ails | (SI       |
|   | ...                     | ple of Test Sequence | the  | **and**   |
|   |                         |                      | d    | II should |
|   | Test #2 Multisite TL    | ...                  | iffe | be        |
|   | Timer and Lockout:      |                      | rent | tested)   |
|   | Restart Capability and  | > b\. Test #2 -      | case |           |
|   | Sensitivity to All      | > Multisite TL Timer | for  | Working   |
|   | Valid Formats (All      | > and Lockout:       | each | paper     |
|   | Transponder)            | > Restart Capability | type | SC20      |
|   |                         | > and Sensitivity to | of   | 9-WP05-07 |
|   | **Time (sec) Action**   | > Valid Formats (All | i    | discusses |
|   |                         | > Transponders)      | nter |           |
|   | 0.0 Start timer with    | >                    | roga |           |
|   | UF=4.                   | > \(1\) run test for | tion |           |
|   |                         | > each IIS related   | (DI  |           |
|   | 0.02 Verify lockout to  | > TL timer, using    | = 1  |           |
|   | timer's II or SI.       | > DI=1               | and  |           |
|   |                         |                      | 7    |           |
|   | 4.5 Restart timer with  |   --------------     | with |           |
|   | UF=5.                   | ------ ------------- | LOS  |           |
|   |                         |   [Time]{            | = 1  |           |
|   | 21.4 Verify lockout for | .underline}   Action | and  |           |
|   | timer's II or SI.       |   (                  | DI = |           |
|   |                         | sec)                 | 3    |           |
|   | 23.6 Verify non-lockout |                      | LSS  |           |
|   | for timer's II or SI.   |                      | =    |           |
|   |                         |                      | 1).  |           |
|   | Interlace all timers in |                      | Fur  |           |
|   | approximately           |   0.00               | ther |           |
|   | 0.3-second intervals.   |          Start timer | more |           |
|   |                         |                      | for  |           |
|   | For Level 2             |        with UF=4, DI | the  |           |
|   | transponders and above, |                      | se   |           |
|   | alternate using UF=4    |         = 1, LOS = 1 | cond |           |
|   | and UF=20               |                      | type |           |
|   | interrogations to start |   0.02               | of   |           |
|   | the timers, and         |               Verify | i    |           |
|   | alternate using UF=5    |                      | nter |           |
|   | and UF=21               |           lockout to | roga |           |
|   | interrogations to       |                      | tion |           |
|   | restart timers.         |          timer\'s II | UF5  |           |
|   |                         |                      | foll |           |
|   | If the test at 21.4     |        with UF = 11. | owed |           |
|   | seconds fails, the      |                      | by   |           |
|   | timer has not been      |   4.5                | UF4  |           |
|   | restarted.              |        Restart timer | is   |           |
|   |                         |                      | prop |           |
|   |                         |        with UF=5, DI | osed |           |
|   |                         |                      | in   |           |
|   |                         |        = 1, LOS = 1. | ED   |           |
|   |                         |                      | whe  |           |
|   |                         |   21.4               | reas |           |
|   |                         |               Verify | DO   |           |
|   |                         |                      | is   |           |
|   |                         |          lockout for | al   |           |
|   |                         |                      | ways |           |
|   |                         |          timer\'s II | u    |           |
|   |                         |                      | sing |           |
|   |                         |        with UF = 11. | UF4  |           |
|   |                         |                      | foll |           |
|   |                         |   23.6               | owed |           |
|   |                         |               Verify | by   |           |
|   |                         |                      | UF5. |           |
|   |                         |          non-lockout |      |           |
|   |                         |                      | Same |           |
|   |                         |         for timer\'s | com  |           |
|   |                         |                      | ment |           |
|   |                         |         II with UF = | for  |           |
|   |                         |                      | Test |           |
|   |                         |                  11. | #3   |           |
|   |                         |   --------------     | with |           |
|   |                         | ------ ------------- | UF20 |           |
|   |                         |                      | /21. |           |
|   |                         | > Interlace all      |      |           |
|   |                         | > timers in          |      |           |
|   |                         | > approximately 0.3  |      |           |
|   |                         | > second intervals.  |      |           |
|   |                         | >                    |      |           |
|   |                         | > If the test at     |      |           |
|   |                         | > 21.4 seconds       |      |           |
|   |                         | > fails, the timer   |      |           |
|   |                         | > has not been       |      |           |
|   |                         | > restarted.         |      |           |
|   |                         | >                    |      |           |
|   |                         | > \(2\) run test for |      |           |
|   |                         | > each IIS related   |      |           |
|   |                         | > TL timer, using    |      |           |
|   |                         | > DI=7               |      |           |
|   |                         |                      |      |           |
|   |                         |   --------------     |      |           |
|   |                         | ------ ------------- |      |           |
|   |                         |   [Time]{            |      |           |
|   |                         | .underline}   Action |      |           |
|   |                         |   (                  |      |           |
|   |                         | sec)                 |      |           |
|   |                         |                      |      |           |
|   |                         |                      |      |           |
|   |                         |                      |      |           |
|   |                         |                      |      |           |
|   |                         |   0.00               |      |           |
|   |                         |          Start timer |      |           |
|   |                         |                      |      |           |
|   |                         |           with UF=5, |      |           |
|   |                         |                      |      |           |
|   |                         |         DI=7, LOS=1. |      |           |
|   |                         |                      |      |           |
|   |                         |   0.02               |      |           |
|   |                         |               Verify |      |           |
|   |                         |                      |      |           |
|   |                         |           lockout to |      |           |
|   |                         |                      |      |           |
|   |                         |          timer\'s II |      |           |
|   |                         |                      |      |           |
|   |                         |        with UF = 11. |      |           |
|   |                         |                      |      |           |
|   |                         |   4.5                |      |           |
|   |                         |        Restart timer |      |           |
|   |                         |                      |      |           |
|   |                         |           with UF=4, |      |           |
|   |                         |                      |      |           |
|   |                         |         DI=7, LOS=1. |      |           |
|   |                         |                      |      |           |
|   |                         |   21.4               |      |           |
|   |                         |               Verify |      |           |
|   |                         |                      |      |           |
|   |                         |          lockout for |      |           |
|   |                         |                      |      |           |
|   |                         |          timer\'s II |      |           |
|   |                         |                      |      |           |
|   |                         |        with UF = 11. |      |           |
|   |                         |                      |      |           |
|   |                         |   23.6               |      |           |
|   |                         |               Verify |      |           |
|   |                         |                      |      |           |
|   |                         |          non-lockout |      |           |
|   |                         |                      |      |           |
|   |                         |         for timer\'s |      |           |
|   |                         |                      |      |           |
|   |                         |         II with UF = |      |           |
|   |                         |                      |      |           |
|   |                         |                  11. |      |           |
|   |                         |   --------------     |      |           |
|   |                         | ------ ------------- |      |           |
|   |                         |                      |      |           |
|   |                         | > Interlace all      |      |           |
|   |                         | > timers in          |      |           |
|   |                         | > approximately 0.3  |      |           |
|   |                         | > second intervals.  |      |           |
|   |                         | >                    |      |           |
|   |                         | > If the test at     |      |           |
|   |                         | > 21.4 seconds       |      |           |
|   |                         | > fails, the timer   |      |           |
|   |                         | > has not been       |      |           |
|   |                         | > restarted          |      |           |
|   |                         | >                    |      |           |
|   |                         | > \(3\) run test for |      |           |
|   |                         | > each SIS related   |      |           |
|   |                         | > TL timer, using    |      |           |
|   |                         | > DI=3               |      |           |
|   |                         |                      |      |           |
|   |                         |   --------------     |      |           |
|   |                         | ------ ------------- |      |           |
|   |                         |   [Time]{            |      |           |
|   |                         | .underline}   Action |      |           |
|   |                         |   (                  |      |           |
|   |                         | sec)                 |      |           |
|   |                         |                      |      |           |
|   |                         |                      |      |           |
|   |                         |                      |      |           |
|   |                         |                      |      |           |
|   |                         |   0.00               |      |           |
|   |                         |          Start timer |      |           |
|   |                         |                      |      |           |
|   |                         |           with UF=4, |      |           |
|   |                         |                      |      |           |
|   |                         |         DI=3, LSS=1. |      |           |
|   |                         |                      |      |           |
|   |                         |   0.02               |      |           |
|   |                         |               Verify |      |           |
|   |                         |                      |      |           |
|   |                         |           lockout to |      |           |
|   |                         |                      |      |           |
|   |                         |          timer\'s SI |      |           |
|   |                         |                      |      |           |
|   |                         |        with UF = 11. |      |           |
|   |                         |                      |      |           |
|   |                         |   4.5                |      |           |
|   |                         |        Restart timer |      |           |
|   |                         |                      |      |           |
|   |                         |           with UF=5, |      |           |
|   |                         |                      |      |           |
|   |                         |         DI=3, LSS=1. |      |           |
|   |                         |                      |      |           |
|   |                         |   21.4               |      |           |
|   |                         |               Verify |      |           |
|   |                         |                      |      |           |
|   |                         |          lockout for |      |           |
|   |                         |                      |      |           |
|   |                         |          timer\'s SI |      |           |
|   |                         |                      |      |           |
|   |                         |        with UF = 11. |      |           |
|   |                         |                      |      |           |
|   |                         |   23.6               |      |           |
|   |                         |               Verify |      |           |
|   |                         |                      |      |           |
|   |                         |          non-lockout |      |           |
|   |                         |                      |      |           |
|   |                         |         for timer\'s |      |           |
|   |                         |                      |      |           |
|   |                         |         SI with UF = |      |           |
|   |                         |                      |      |           |
|   |                         |                  11. |      |           |
|   |                         |   --------------     |      |           |
|   |                         | ------ ------------- |      |           |
|   |                         |                      |      |           |
|   |                         | > Interlace all      |      |           |
|   |                         | > timers in          |      |           |
|   |                         | > approximately 0.3  |      |           |
|   |                         | > second intervals.  |      |           |
|   |                         | >                    |      |           |
|   |                         | > If the test at     |      |           |
|   |                         | > 21.4 seconds       |      |           |
|   |                         | > fails, the timer   |      |           |
|   |                         | > has not been       |      |           |
|   |                         | > restarted.         |      |           |
+---+-------------------------+----------------------+------+-----------+
| 4 |                         | 5.5.8.5 p 202/203    | No   | SC- 209   |
| 8 |                         |                      | eq   | to        |
| . |                         | **Procedure #5       | uiva | consider  |
|   |                         | Selective Lockout    | lent | to add    |
|   |                         | Tests (Paragraph     | test | this      |
|   |                         | 3.20.2.5)**          | s    | test.     |
|   |                         |                      | teps |           |
|   |                         | ...                  | in   |           |
|   |                         |                      | DO   |           |
|   |                         | ##                   |      |           |
|   |                         | ### 5.5.8.5.3 Princi |      |           |
|   |                         | ple of Test Sequence |      |           |
|   |                         |                      |      |           |
|   |                         | ...                  |      |           |
|   |                         |                      |      |           |
|   |                         | > d\. Test #4 -      |      |           |
|   |                         | > Broadcast          |      |           |
|   |                         | > Discrimination     |      |           |
|   |                         | > related to IIS     |      |           |
|   |                         | >                    |      |           |
|   |                         | > ...                |      |           |
|   |                         |                      |      |           |
|   |                         | e.  Test #5 -        |      |           |
|   |                         |     Broadcast        |      |           |
|   |                         |     Discrimination   |      |           |
|   |                         |     related to SIS   |      |           |
|   |                         |                      |      |           |
|   |                         | > ...                |      |           |
+---+-------------------------+----------------------+------+-----------+

##  Squitter

+---+-------------------------+----------------------+------+-----------+
| \ | Do-181                  | ED-73                | Com  | Proposal  |
| # |                         |                      | ment |           |
+===+=========================+======================+======+===========+
| 4 | 2.5.4.6.1 p 193/194     | \-                   | Squi | Eurocae   |
| 9 |                         |                      | tter | WG49 to   |
| . | **Acquisition Squitter  |                      | to   | add this  |
|   | Verification**          |                      | be   | test in   |
|   |                         |                      | revi | ED 73     |
|   | The following test      |                      | ewed | (5.5.8.6) |
|   | **shall** verify proper |                      | in   | and to    |
|   | transmission of         |                      | ED.  | update    |
|   | Acquisition squitters   |                      | The  | the       |
|   | when the transponder is |                      | t    | req       |
|   | not transmitting        |                      | ests | uirements |
|   | Extended Squitters. The |                      | c    | (         |
|   | following tests         |                      | orre | 3.20.2.6) |
|   | **shall** be conducted  |                      | spon |           |
|   | with no external data   |                      | ding | =\> see   |
|   | input to the Extended   |                      | to   | following |
|   | Squitter GICB           |                      | the  | item      |
|   | registers.              |                      | requ | (S-50)    |
|   |                         |                      | irem |           |
|   | Step 1: Setup the       |                      | ents | Do we     |
|   | transponder to airborne |                      | def  | just need |
|   | status. The Acquisition |                      | ined | to change |
|   | squitter transmission   |                      | in   | the para  |
|   | **shall** be verified   |                      | 3.20 | reference |
|   | to be uniformly         |                      | .2.6 | to        |
|   | distributed between 0.8 |                      | and  | 5.4.3.2.2 |
|   | and 1.2 seconds with a  |                      | 3.21 | step 7 &  |
|   | time quantization less  |                      | .2.6 | 5.4.3.2.3 |
|   | than or equal to 15     |                      | s    |           |
|   | milliseconds. The test  |                      | hall |           |
|   | setup will require      |                      | be   |           |
|   | measuring the time      |                      | defi |           |
|   | difference between      |                      | ned. |           |
|   | successive Acquisition  |                      |      |           |
|   | squitters. The time     |                      |      |           |
|   | interval measured       |                      |      |           |
|   | between successive      |                      |      |           |
|   | Acquisition squitters   |                      |      |           |
|   | **shall** be counted in |                      |      |           |
|   | individual 15           |                      |      |           |
|   | millisecond bins        |                      |      |           |
|   | between 0.8 and 1.2     |                      |      |           |
|   | seconds. Validation of  |                      |      |           |
|   | the proper quantization |                      |      |           |
|   | is achieved upon        |                      |      |           |
|   | receipt of at least one |                      |      |           |
|   | Acquisition squitter in |                      |      |           |
|   | each 15 millisecond     |                      |      |           |
|   | time bin between 0.8    |                      |      |           |
|   | and 1.2 seconds.        |                      |      |           |
|   | Improper times are      |                      |      |           |
|   | those occurring outside |                      |      |           |
|   | of the time bins        |                      |      |           |
|   | between 0.8 and 1.2     |                      |      |           |
|   | seconds. Verify that    |                      |      |           |
|   | the Acquisition         |                      |      |           |
|   | squitters are uniformly |                      |      |           |
|   | distributed over the    |                      |      |           |
|   | interval between 0.8    |                      |      |           |
|   | and 1.2 seconds.        |                      |      |           |
|   |                         |                      |      |           |
|   | Step 2: Verify the      |                      |      |           |
|   | content of the CA, AA   |                      |      |           |
|   | and PI fields. For      |                      |      |           |
|   | diversity transponders, |                      |      |           |
|   | verify that the         |                      |      |           |
|   | squitters occur         |                      |      |           |
|   | alternately from both   |                      |      |           |
|   | channels. For           |                      |      |           |
|   | transponders that are   |                      |      |           |
|   | designed for aircraft   |                      |      |           |
|   | installations with      |                      |      |           |
|   | automatic means of      |                      |      |           |
|   | determining             |                      |      |           |
|   | on-the-ground           |                      |      |           |
|   | condition, when the     |                      |      |           |
|   | transponder is in       |                      |      |           |
|   | on-the-ground status,   |                      |      |           |
|   | verify that Acquisition |                      |      |           |
|   | squitters occur on the  |                      |      |           |
|   | top antenna only at the |                      |      |           |
|   | prescribed rate.        |                      |      |           |
+---+-------------------------+----------------------+------+-----------+
| 5 | 2.54.6.2 p 194          | 5.5.8.6 p 205        | Exte | WG-49 :   |
| 0 |                         |                      | nded | To reuse  |
| . | **Extended Squitter     | #### PROCEDURE       | squi | the       |
|   | Verification**          |  #6 Squitter Verific | tter | procedure |
|   |                         | ation (Paragraphs 3. | to   |           |
|   | Extended squitters      | 20.2.6 and 3.21.2.6) | be   | from      |
|   | occur randomly at rates |                      | d    | DO181     |
|   | determined by internal  | The squitter         | iscu | 2.5.4.6   |
|   | states of the           | transmissions        | ssed | (         |
|   | transponder. Each       | function of          | in   | 2.5.4.6.1 |
|   | Extended Squitter type  | transponders cannot  | EUR  | and       |
|   | must be separately      | be externally        | OCAE | 2         |
|   | verified for content,   | disabled. Squitters  |      | .5.4.6.2) |
|   | rate and antenna        | will occur randomly  |      | and add   |
|   | selection which are     | at approximately     |      | random    |
|   | dependent upon          | one-second intervals |      | tra       |
|   | transponder air/ground  | during all test      |      | nsmission |
|   | state and Extended      | procedures.          |      | test in   |
|   | Squitter ground station |                      |      | extended  |
|   | interrogations. The     | As a result,         |      | squitter  |
|   | selection of airborne   | squitter             |      | p         |
|   | or surface position     | transmissions will   |      | rocedure. |
|   | formats are dependent   | be noted by the      |      |           |
|   | upon determination of   | reply receiver and   |      | Do we     |
|   | on-the-ground status    | the test controller  |      | just need |
|   | and ground station      | as unsolicited       |      | to change |
|   | control via             | replies. Software or |      | the para  |
|   | interrogation content.  | hardware provisions  |      | reference |
|   | The following tests     | shall be made in the |      | to        |
|   | **shall** be performed  | test setup so that   |      | 5.4.3.2.2 |
|   | to verify proper        | squitter             |      | step 7 &  |
|   | operation of the        | transmissions are    |      | 5.4.3.2.3 |
|   | transponder Extended    | recognized as such,  |      |           |
|   | Squitter functions. The | and it should be     |      | SC209 to  |
|   | external data sources   | noted that they      |      | consider  |
|   | for Extended Squitter   | occur in the         |      | the add   |
|   | loading **shall** be    | specified random     |      | of random |
|   | connected via the       | manner.              |      | tra       |
|   | appropriate interfaces. |                      |      | nsmission |
|   |                         | The following is     |      | test in   |
|   | ...                     | recommended: If an   |      | extended  |
|   |                         | unsolicited reply is |      | squitter  |
|   |                         | detected, the        |      | test      |
|   |                         | processor shall      |      | procedure |
|   |                         | delay the next       |      | (2        |
|   |                         | scheduled            |      | .5.4.6.2) |
|   |                         | interrogation so     |      |           |
|   |                         | that it doesn\'t     |      | -         |
|   |                         | overlap the squitter |      |  Suppress |
|   |                         | transmissions and    |      |           |
|   |                         | remain undetected by |      | >         |
|   |                         | the transponder.     |      |  Extended |
|   |                         |                      |      | > and     |
|   |                         | When squitter        |      | > ac      |
|   |                         | transmissions are    |      | quisition |
|   |                         | detected, their      |      | >         |
|   |                         | content shall be     |      |  squitter |
|   |                         | verified observing   |      | > tests   |
|   |                         | the CA, AA and PI    |      | > from    |
|   |                         | fields of the        |      | > 5.4     |
|   |                         | transmissions.       |      | >         |
|   |                         |                      |      |  chapter. |
|   |                         | For diversity        |      | >         |
|   |                         | transponders, it     |      | > And Add |
|   |                         | shall be verified    |      | > what    |
|   |                         | that squitters are   |      | > has     |
|   |                         | transmitted          |      | > been    |
|   |                         | alternately from     |      | > done in |
|   |                         | both channels.       |      | > DO181   |
|   |                         |                      |      | > in      |
|   |                         | For tests of the     |      | > chapter |
|   |                         | squitter function,   |      | > 5.5     |
|   |                         | refer to paragraph   |      |           |
|   |                         | 5.4.11.2.            |      |           |
+---+-------------------------+----------------------+------+-----------+
| 5 | 2.5.4.9 p 205           | 5.5.8.9 p 207        | To   | WG-49 ED  |
| 1 |                         |                      | c    | : take    |
| . | **Procedure #9 Address  | **Procedure #9       | heck | the DO    |
|   | Tests**                 | Address Tests**      | why  | text. And |
|   |                         |                      | this | add that  |
|   | This test procedure     | ##### 5.5.8.9        | p    | this test |
|   | verifies that the       | .1 Pattern Selection | atte | should be |
|   | address set into the    |                      | rn + | done with |
|   | address interface of    | Because more than 16 | if   | the two   |
|   | the transponder is only | million addresses    | in   | following |
|   | accepted during         | are possible,        | puts | address   |
|   | power-up or unit reset, | exhaustive testing   | bit  | patterns  |
|   | that the accepted       | is not practical.    | to   | AAAAAA    |
|   | address set is actually | Address test         | c    | and       |
|   | the address to which    | patterns must be     | onfi | 555555.   |
|   | the transponder         | chosen so that the   | gure |           |
|   | responds, and that the  | most likely failure  |      | ~~SC209 : |
|   | accepted address is the | modes (incorrect     |      | To        |
|   | only address which the  | wiring of the        |      | consider  |
|   | transponder reports in  | interface connector, |      | the same  |
|   | DF=11. It is also       | register             |      | amendment |
|   | verified that this      | malfunction, etc.)   |      | (AAAAAA   |
|   | accepted address        | can be found.        |      | and       |
|   | pattern is used in      |                      |      | 5         |
|   | generating the AP field | As a minimum the 276 |      | 55555).~~ |
|   | of replies and that the | address patterns     |      |           |
|   | transponder does reply  | consisting of two    |      | SC209     |
|   | only to this address.   | ONEs and 22 ZEROs    |      | already   |
|   |                         | (Pattern group A)    |      | step      |
|   |                         | and the 276 patterns |      | through   |
|   |                         | having two ZEROs and |      | the       |
|   |                         | 22 ONEs (Pattern     |      | com       |
|   |                         | group B) shall be    |      | binations |
|   |                         | used for             |      | in        |
|   |                         | verification.        |      | 2         |
|   |                         |                      |      | .3.2.11.1 |
|   |                         |                      |      | step 5 &  |
|   |                         |                      |      | 2         |
|   |                         |                      |      | .4.2.12.1 |
|   |                         |                      |      | so do not |
|   |                         |                      |      | need to   |
|   |                         |                      |      | add the   |
|   |                         |                      |      | extra     |
|   |                         |                      |      | tests,    |
|   |                         |                      |      | WG49 to   |
|   |                         |                      |      | check for |
|   |                         |                      |      | the same  |
|   |                         |                      |      | and then  |
|   |                         |                      |      | adopt the |
|   |                         |                      |      | DO181     |
|   |                         |                      |      | text (ED  |
|   |                         |                      |      | 5         |
|   |                         |                      |      | .4.12.1.2 |
|   |                         |                      |      | refers)   |
+---+-------------------------+----------------------+------+-----------+