***RCS WRC --07 Agenda Item Scope and High-Level Work Plan***[^1]

**Agenda Item 1.21:** to consider the results of studies, regarding the
compatibility between the radio astronomy service and the active space
services in accordance with Resolution **740 (WRC--03)**, in order to
review and update, if appropriate, the tables of threshold levels used
for consultation that appear in the Annex to Resolution
**739 (WRC--03).**

**Short Description:** Resolution **740 (WRC--03)** calls for studies of
compatibility between the radio astronomy service and unwanted emissions
from particular active space services in thirteen specified pairs of
active and passive service frequency bands. It also calls for the review
and update, if appropriate, of the Resolution **739 (WRC--03)**
threshold levels for consultation, considering the results of the
studies.

**Background:** Under part of Agenda Item 1.8.2, WRC--03 considered
compatibility between unwanted emissions and the radio astronomy service
in pairs of active and passive service bands. Proposals ranged from hard
limits on the space service unwanted emissions to no action. Other
administrations favored consultation between administrations as a middle
approach.

The Conference approved Resolution **739**, which calls for consultation
between affected administrations when space system unwanted emissions in
certain radio astronomy bands do not meet threshold values at radio
telescope sites. The Conference also approved Resolution **740** along
with inclusion of the radio astronomy protection issue in the agenda for
WRC--07.

CPM06--1 designated a task group of Study Group 1 as the responsible
group for Agenda Item 1.21. At its November 2003 meeting, Study Group 1
established Task Group 1/9 to conduct studies and draft CPM text for
this agenda item. The first CPM also designated Working Parties 4A, 6S,
7D and 8D as the contributing groups.

**Scope of Agenda Item:** Whereas WRC--03 Agenda Item 1.8.2 was not
specific on the bands to be studied, Resolution **740 (WRC--03)** for
WRC--07 applies to nine radio astronomy bands and thirteen adjacent or
nearby active service bands. At WRC--07, solutions for radio astronomy
protection will be limited to setting consultation thresholds in the
specified additional bands.

**Key technical/regulatory issues to be resolved:**

-   Appropriate basis for setting thresholds for consultation between
    administrations

-   Quantity of systems for which consultation would be required

-   Benefits of consultation in protecting radio astronomy

-   Impact of consultation on the administration, and on active service
    users, providers and equipment manufacturers

**Key policy issues to be resolved:**

-   Effect of planned U.S. implementation on the choice of threshold
    levels

**Work Plan:**

1.  Engage the FCC in discussions to consider appropriate threshold
    levels

2.  Determine what studies are of use in setting threshold levels for
    consultation

3.  Determine the appropriate method of documenting the necessary
    studies

4.  Contribute to and participate in Task Group 1/9 studies for setting
    threshold levels for consultation

5.  Develop a proposal for appropriate threshold levels for pairs of
    frequency bands listed in Resolution **740**

6.  Obtain support of CITEL and other administrations on the U.S.
    proposal

7.  Review and document experiences with consultation under
    Resolution **739**

**Reference Material:**

-   Resolutions **739** and **740 (WRC--03)**

-   Recommendations ITU--R SM.1633 and RA.769

attachment

RESOLUTION 739 \[COM4/15\] (WRC‑03)

Compatibility between the radio astronomy service and the active\
space services in certain adjacent and nearby frequency bands

The World Radiocommunication Conference (Geneva, 2003),

considering

*a)* that adjacent or nearby primary service allocations have been made
to the radio astronomy service, and to various space services, such as
the fixed‑satellite service (FSS), radionavigation satellite service
(RNSS), mobile‑satellite service (MSS) and broadcasting‑satellite
service (BSS), hereafter referred to as "active space services";

*b)* that, in many cases, the frequencies used by the radio astronomy
service (RAS) are chosen to study natural phenomena producing radio
emissions at frequencies fixed by the laws of nature, so shifting
frequency to avoid or mitigate interference problems may not be
possible;

*c)* that Recommendation ITU‑R SM.1633 provides a methodology for
conducting, and a framework for documenting the results of,
compatibility studies between active space service and passive service
band-pairs;

*d)* that Recommendation ITU‑R SM.1633 also provides the results of
compatibility studies between a passive service and an active space
service in certain adjacent and nearby bands;

*e)* that appropriate consultation between administrations has the
potential to lead to the development of innovative solutions and to the
rapid deployment of systems;

*f)* that, for technical or operational reasons, more stringent spurious
emission limits than the general limits in Appendix **3** may be
required to protect the RAS from active services in specific bands,

noting

*a)* that the additional burden of undertaking any technical examination
should not be placed on the Radiocommunication Bureau;

*b)* that a consultation procedure, as contained in this Resolution,
would not place an additional burden on the Radiocommunication Bureau;

*c)* that Recommendation ITU‑R M.1583 provides a methodology based on
the equivalent power flux-density (epfd) concept for calculation of
interference resulting from unwanted emissions from non-geostationary
(non-GSO) satellite systems of the MSS or RNSS into radio astronomy
stations;

*d)* that Recommendation ITU‑R S.1586 provides a methodology based on
the epfd concept for calculation of interference resulting from unwanted
emissions from non-GSO systems of the FSS into radio astronomy stations;

*e)* that Recommendation ITU‑R RA.1631 provides antenna patterns to be
used for compatibility analyses between non‑GSO systems and RAS
stations, based on the epfd concept;

*f)* that Recommendation ITU‑R RA.1513 provides acceptable levels of
data loss to radio astronomy observations, stating in particular that
the percentage of data loss caused by any system should be lower than
2%;

*g)* that some of the results documented in Recommendation ITU‑R SM.1633
may be used as threshold levels to initiate the consultation procedure;

*h)* that the results of successful consultation between concerned
administrations would ensure that the interests of both the active and
passive services are considered;

*i)* that measures taken by active space services to protect radio
astronomy stations from interference may result in increased costs
and/or reduced capabilities for those services;

*j)* that conversely, not taking such measures may result in additional
operating costs and reduced operational effectiveness for the radio
astronomy stations concerned;

*k)* that the implementation of additional interference mitigation
measures at the radio astronomy station may increase operating costs and
reduce observational effectiveness;

*l)* that conversely, not implementing such measures may impose upon the
active space services an additional cost burden and reduction in service
capability;

*m)* that studies for some of the band-pairs listed in Recommendation
ITU‑R SM.1633 are still in progress,

recognizing

*a)* that unwanted emissions produced by stations of the active space
services may cause unacceptable interference to stations of the RAS;

*b)* that, although some unwanted emissions from transmitters on space
stations can be controlled through careful design methods and
appropriate testing procedures, other unwanted emissions, such as
narrowband spurious emissions, generated by uncontrollable and/or
unpredictable physical mechanisms, may only be detected after the
spacecraft is launched;

*c)* that there is an uncertainty in the pre-launch assessment of the
levels of unwanted emissions;

*d)* that it is necessary to ensure an equitable sharing of burden for
achieving compatibility between the active space services and the RAS;

*e)* that for those cases where difficulties are encountered in meeting
the values in the Annex, a consultation procedure could be used to
resolve the difficulties,

resolves

1 that an administration takes all reasonable steps to ensure that space
stations being designed and constructed to operate in the bands in the
Annex meet the values given therein at any radio astronomy station
operating in the corresponding bands identified in the Annex;

2 that in the event that during construction and prior to launch it is
determined that, after having considered all reasonable means, the
unwanted emissions from the space station cannot meet the values given
in the Annex, the administration that notified the space station
contacts, as soon as possible, the administration operating the radio
astronomy station:

*a)* to confirm that *resolves* 1 has been fulfilled; and

*b)* the concerned administrations enter into a consultation process in
order to identify all practicable steps with a view to achieving a
mutually acceptable solution;

3 that in the event, following the space station launch, an
administration operating a radio astronomy station determines that, due
to unexpected circumstances, a space station does not meet the values
for unwanted emissions given in the Annex to this Resolution at that
radio astronomy station, it contacts the administration that notified
the space station, so that:

*a)* the administration that notified the space station confirms that
*resolves* 1 has been fulfilled; and

*b)* the concerned administrations enter into a consultation process in
order to identify further steps with a view to achieving a mutually
acceptable solution;

4 that the radio astronomy stations to be taken into account in applying
*resolves* 1, 2 and 3 are those which are operating in the frequency
band(s) identified in the Annex to this Resolution and which are
notified before the date of reception of the advance publication
information of the space station to which this Resolution applies;

5 that the space stations to be considered in the application of the
above *resolves* are those designed to operate in the space service
frequency bands listed in the Annex for which advance publication
information is received by the Radiocommunication Bureau following the
entry into force of the Final Acts of this conference;

6 that the objective of the consultation process in *resolves *1, 2
and 3 is to achieve a mutually acceptable solution, using as guidance
Recommendation ITU‑R SM.1633 and any other ITU‑R Recommendations deemed
relevant by the concerned administrations;

7 that the Radiocommunication Bureau shall make no examination or
finding with respect to this Resolution under either Article **9**
or **11**,

invites administrations

1 to take all appropriate and practicable steps, from the design phase
onward, to ensure that unwanted emissions are minimized from space
stations that are planned to operate in one or more space service
allocations, in order to avoid exceeding the threshold levels of
unwanted emissions identified in the Annex to this Resolution at any
radio astronomy station;

2 to take all practicable steps, from the design phase onward, to
minimize the sensitivity of radio astronomy stations to interference and
to take into account the need to implement interference mitigation
measures.

ANNEX TO RESOLUTION 739 \[COM4/15\] (WRC-03)

Unwanted emission threshold levels

The unwanted emission threshold levels applicable to geostationary space
stations are given in Table 1‑1 in terms of power flux-density (pfd) in
a reference bandwidth produced at a radio astronomy station.

In Table 1‑1 the unwanted emission threshold levels given in the fourth,
sixth and eighth columns (associated with the reference bandwidth
contained in the adjacent columns) should be met by space stations
operating in the bands indicated in the second column at the radio
astronomy station operating in the band mentioned in the third column.

The unwanted emission threshold levels applicable to space stations of
non-geostationary systems are given in Table 1‑2 in terms of the
equivalent power flux-density (epfd), produced at a radio astronomy
station in a reference bandwidth, not to be exceeded during a given
percentage of time, over the whole sky.

In Table 1‑2 the epfd value given in the fourth, sixth and eighth
columns (associated with the reference bandwidths contained in the
adjacent column) should be met by space stations operating in the bands
indicated in the second column at the radio astronomy station operating
in the band mentioned in the third column. The epfd value at a given
radio astronomy station shall be evaluated by using the antenna pattern
and the RAS maximum antenna gain given in Recommendation ITU‑R RA.1631.
Guidance on the calculation of epfd can be found in Recommendations
ITU‑R S.1586 and ITU‑R M.1583. The elevation angles of the radio
astronomy stations to be taken into account in the epfd calculation are
those higher than the minimum elevation angle θ*~min~* of the radio
telescope. In the absence of such information a value of 5° shall be
taken. The percentage of time during which the epfd level shall not be
exceeded is mentioned in Note ^(1)^ of Table 1‑2.

Table 1-1

pfd thresholds for unwanted emissions from geostationary space stations\
at a radio astronomy station

+----------+---------+-----------+-----+------+------+------+-------+
| **Space  | Space   | Radio     | Sin |      | Si   |      | VLBI  |
| s        | s       | a         | gle |      | ngle |      | ^(1)^ |
| ervice** | ervice\ | stronomy\ | di  |      | d    |      |       |
|          | band    | band      | sh, |      | ish, |      |       |
|          |         |           | con |      | spec |      |       |
|          |         |           | tin |      | tral |      |       |
|          |         |           | uum |      | line |      |       |
|          |         |           | obs |      | obse |      |       |
|          |         |           | erv |      | rvat |      |       |
|          |         |           | ati |      | ions |      |       |
|          |         |           | ons |      |      |      |       |
+----------+---------+-----------+-----+------+------+------+-------+
|          |         |           | pf  | R    | pfd^ | R    | pfd   |
|          |         |           | d^( | efer | (2)^ | efer | ^(2)^ |
|          |         |           | 2)^ | ence |      | ence |       |
|          |         |           |     | b    |      | b    |       |
|          |         |           |     | andw |      | andw |       |
|          |         |           |     | idth |      | idth |       |
+----------+---------+-----------+-----+------+------+------+-------+
|          | MHz     | MHz       | d   | MHz  | dB   | kHz  | dB(W/ |
|          |         |           | B(W |      | (W/m |      | m^2^) |
|          |         |           | /m^ |      | ^2^) |      |       |
|          |         |           | 2^) |      |      |      |       |
+----------+---------+-----------+-----+------+------+------+-------+
| BSS      | 1 452-1 | 1 400-1   | --  | 27   | -    | 20   | --166 |
| (        | 492\    | 427       | 180 |      | -196 |      |       |
| s-to-E)\ | 1 525-1 |           |     |      |      |      |       |
| MSS      | 559     |           |     |      |      |      |       |
| (s-to-E) |         |           |     |      |      |      |       |
+----------+---------+-----------+-----+------+------+------+-------+
| MSS      | 1 525-1 | 1 610.6-1 | NA  | NA   | -    | 20   | --166 |
| (        | 559\    | 613.8     |     |      | -194 |      |       |
| s-to-E)\ | 1       |           |     |      |      |      |       |
| MSS      | 613.8-1 |           |     |      |      |      |       |
| (s-to-E) | 626.5   |           |     |      |      |      |       |
+----------+---------+-----------+-----+------+------+------+-------+
| BSS      | 2 655-2 | 2 690-2   | --  | 10   | NR   | 25   | --161 |
| (        | 670     | 700       | 177 |      |      |      |       |
| s-to-E)\ |         |           |     |      |      |      |       |
| FSS      |         |           |     |      |      |      |       |
| (s-to-E) |         |           |     |      |      |      |       |
+----------+---------+-----------+-----+------+------+------+-------+
| FSS      | 2 670-2 | 2 690-2   | --  | 10   | NR   | 20   | --161 |
| (s-to-E) | 690     | 700\      | 177 |      |      |      |       |
|          |         | (in       |     |      |      |      |       |
|          |         | Regions 1 |     |      |      |      |       |
|          |         | and 3)    |     |      |      |      |       |
+----------+---------+-----------+-----+------+------+------+-------+
|          | GHz     | GHz       | --  | --   | --   | --   | --    |
+----------+---------+-----------+-----+------+------+------+-------+
| BSS      | 21      | 2         | NR  | NR   | NR   | 250  | --128 |
| (s-to-E) | .4-22.0 | 2.21-22.5 |     |      |      |      |       |
+----------+---------+-----------+-----+------+------+------+-------+
| NA: Not  |         |           |     |      |      |      |       |
| app      |         |           |     |      |      |      |       |
| licable, |         |           |     |      |      |      |       |
| meas     |         |           |     |      |      |      |       |
| urements |         |           |     |      |      |      |       |
| of this  |         |           |     |      |      |      |       |
| type are |         |           |     |      |      |      |       |
| not made |         |           |     |      |      |      |       |
| in this  |         |           |     |      |      |      |       |
| band.    |         |           |     |      |      |      |       |
|          |         |           |     |      |      |      |       |
| NR: No   |         |           |     |      |      |      |       |
| result   |         |           |     |      |      |      |       |
| av       |         |           |     |      |      |      |       |
| ailable. |         |           |     |      |      |      |       |
|          |         |           |     |      |      |      |       |
| ^(1)^    |         |           |     |      |      |      |       |
| The      |         |           |     |      |      |      |       |
| r        |         |           |     |      |      |      |       |
| eference |         |           |     |      |      |      |       |
| b        |         |           |     |      |      |      |       |
| andwidth |         |           |     |      |      |      |       |
| used for |         |           |     |      |      |      |       |
| spectral |         |           |     |      |      |      |       |
| line     |         |           |     |      |      |      |       |
| obse     |         |           |     |      |      |      |       |
| rvations |         |           |     |      |      |      |       |
| has also |         |           |     |      |      |      |       |
| been     |         |           |     |      |      |      |       |
| used as  |         |           |     |      |      |      |       |
| r        |         |           |     |      |      |      |       |
| eference |         |           |     |      |      |      |       |
| b        |         |           |     |      |      |      |       |
| andwidth |         |           |     |      |      |      |       |
| for very |         |           |     |      |      |      |       |
| long     |         |           |     |      |      |      |       |
| baseline |         |           |     |      |      |      |       |
| interf   |         |           |     |      |      |      |       |
| erometry |         |           |     |      |      |      |       |
| (VLBI)   |         |           |     |      |      |      |       |
| obser    |         |           |     |      |      |      |       |
| vations. |         |           |     |      |      |      |       |
| In VLBI  |         |           |     |      |      |      |       |
| bands,   |         |           |     |      |      |      |       |
| where no |         |           |     |      |      |      |       |
| spectral |         |           |     |      |      |      |       |
| line     |         |           |     |      |      |      |       |
| obse     |         |           |     |      |      |      |       |
| rvations |         |           |     |      |      |      |       |
| are      |         |           |     |      |      |      |       |
| co       |         |           |     |      |      |      |       |
| nducted, |         |           |     |      |      |      |       |
| the      |         |           |     |      |      |      |       |
| r        |         |           |     |      |      |      |       |
| eference |         |           |     |      |      |      |       |
| b        |         |           |     |      |      |      |       |
| andwidth |         |           |     |      |      |      |       |
| for VLBI |         |           |     |      |      |      |       |
| obse     |         |           |     |      |      |      |       |
| rvations |         |           |     |      |      |      |       |
| has been |         |           |     |      |      |      |       |
| de       |         |           |     |      |      |      |       |
| termined |         |           |     |      |      |      |       |
| using    |         |           |     |      |      |      |       |
| the      |         |           |     |      |      |      |       |
| as       |         |           |     |      |      |      |       |
| sumption |         |           |     |      |      |      |       |
| of       |         |           |     |      |      |      |       |
| Recomm   |         |           |     |      |      |      |       |
| endation |         |           |     |      |      |      |       |
| ITU‑R    |         |           |     |      |      |      |       |
| RA.769   |         |           |     |      |      |      |       |
| for a    |         |           |     |      |      |      |       |
| typical  |         |           |     |      |      |      |       |
| spec     |         |           |     |      |      |      |       |
| trometer |         |           |     |      |      |      |       |
| channel  |         |           |     |      |      |      |       |
| (        |         |           |     |      |      |      |       |
| 3 km/s). |         |           |     |      |      |      |       |
|          |         |           |     |      |      |      |       |
| ^(2)^    |         |           |     |      |      |      |       |
| In       |         |           |     |      |      |      |       |
| tegrated |         |           |     |      |      |      |       |
| over the |         |           |     |      |      |      |       |
| r        |         |           |     |      |      |      |       |
| eference |         |           |     |      |      |      |       |
| b        |         |           |     |      |      |      |       |
| andwidth |         |           |     |      |      |      |       |
| with an  |         |           |     |      |      |      |       |
| int      |         |           |     |      |      |      |       |
| egration |         |           |     |      |      |      |       |
| time of  |         |           |     |      |      |      |       |
| 2 000 s. |         |           |     |      |      |      |       |
+----------+---------+-----------+-----+------+------+------+-------+

Table 1-2

epfd thresholds^(1)^ for unwanted emissions from non-GSO satellite
systems\
at a radio astronomy station

+---------+---------+-----------+-------+-------+------+------+-----+
| **Space | Space   | Radio     | S     |       | Si   |      | VLB |
| se      | s       | a         | ingle |       | ngle |      | I^( |
| rvice** | ervice\ | stronomy\ | dish, |       | d    |      | 2)^ |
|         | band    | band      | cont  |       | ish, |      |     |
|         |         |           | inuum |       | spec |      |     |
|         |         |           | ob    |       | tral |      |     |
|         |         |           | serva |       | line |      |     |
|         |         |           | tions |       | obse |      |     |
|         |         |           |       |       | rvat |      |     |
|         |         |           |       |       | ions |      |     |
+---------+---------+-----------+-------+-------+------+------+-----+
|         |         |           | epfd  | Refe  | e    | R    | epf |
|         |         |           | ^(3)^ | rence | pfd^ | efer | d^( |
|         |         |           |       | band  | (3)^ | ence | 3)^ |
|         |         |           |       | width |      | b    |     |
|         |         |           |       |       |      | andw |     |
|         |         |           |       |       |      | idth |     |
+---------+---------+-----------+-------+-------+------+------+-----+
|         | MHz     | MHz       | dB(W/ | MHz   | dB   | kHz  | d   |
|         |         |           | m^2^) |       | (W/m |      | B(W |
|         |         |           |       |       | ^2^) |      | /m^ |
|         |         |           |       |       |      |      | 2^) |
+---------+---------+-----------+-------+-------+------+------+-----+
| MSS     | 1       | 1 610.6-1 | NA    | NA    | -    | 20   | --  |
| (       | 613.8-1 | 613.8     |       |       | -258 |      | 230 |
| s-to-E) | 626.5   |           |       |       |      |      |     |
+---------+---------+-----------+-------+-------+------+------+-----+
| NA: Not |         |           |       |       |      |      |     |
| appl    |         |           |       |       |      |      |     |
| icable, |         |           |       |       |      |      |     |
| measu   |         |           |       |       |      |      |     |
| rements |         |           |       |       |      |      |     |
| of this |         |           |       |       |      |      |     |
| type    |         |           |       |       |      |      |     |
| are not |         |           |       |       |      |      |     |
| made in |         |           |       |       |      |      |     |
| this    |         |           |       |       |      |      |     |
| band.   |         |           |       |       |      |      |     |
|         |         |           |       |       |      |      |     |
| ^(1)^   |         |           |       |       |      |      |     |
| These   |         |           |       |       |      |      |     |
| epfd    |         |           |       |       |      |      |     |
| thr     |         |           |       |       |      |      |     |
| esholds |         |           |       |       |      |      |     |
| should  |         |           |       |       |      |      |     |
| not be  |         |           |       |       |      |      |     |
| e       |         |           |       |       |      |      |     |
| xceeded |         |           |       |       |      |      |     |
| for     |         |           |       |       |      |      |     |
| more    |         |           |       |       |      |      |     |
| than 2% |         |           |       |       |      |      |     |
| of      |         |           |       |       |      |      |     |
| time.   |         |           |       |       |      |      |     |
|         |         |           |       |       |      |      |     |
| ^(2)^   |         |           |       |       |      |      |     |
| The     |         |           |       |       |      |      |     |
| re      |         |           |       |       |      |      |     |
| ference |         |           |       |       |      |      |     |
| ba      |         |           |       |       |      |      |     |
| ndwidth |         |           |       |       |      |      |     |
| used    |         |           |       |       |      |      |     |
| for     |         |           |       |       |      |      |     |
| s       |         |           |       |       |      |      |     |
| pectral |         |           |       |       |      |      |     |
| line    |         |           |       |       |      |      |     |
| obser   |         |           |       |       |      |      |     |
| vations |         |           |       |       |      |      |     |
| has     |         |           |       |       |      |      |     |
| also    |         |           |       |       |      |      |     |
| been    |         |           |       |       |      |      |     |
| used as |         |           |       |       |      |      |     |
| re      |         |           |       |       |      |      |     |
| ference |         |           |       |       |      |      |     |
| ba      |         |           |       |       |      |      |     |
| ndwidth |         |           |       |       |      |      |     |
| for     |         |           |       |       |      |      |     |
| VLBI    |         |           |       |       |      |      |     |
| observ  |         |           |       |       |      |      |     |
| ations. |         |           |       |       |      |      |     |
| In VLBI |         |           |       |       |      |      |     |
| bands,  |         |           |       |       |      |      |     |
| where   |         |           |       |       |      |      |     |
| no      |         |           |       |       |      |      |     |
| s       |         |           |       |       |      |      |     |
| pectral |         |           |       |       |      |      |     |
| line    |         |           |       |       |      |      |     |
| obser   |         |           |       |       |      |      |     |
| vations |         |           |       |       |      |      |     |
| are     |         |           |       |       |      |      |     |
| con     |         |           |       |       |      |      |     |
| ducted, |         |           |       |       |      |      |     |
| the     |         |           |       |       |      |      |     |
| re      |         |           |       |       |      |      |     |
| ference |         |           |       |       |      |      |     |
| ba      |         |           |       |       |      |      |     |
| ndwidth |         |           |       |       |      |      |     |
| for     |         |           |       |       |      |      |     |
| VLBI    |         |           |       |       |      |      |     |
| obser   |         |           |       |       |      |      |     |
| vations |         |           |       |       |      |      |     |
| has     |         |           |       |       |      |      |     |
| been    |         |           |       |       |      |      |     |
| det     |         |           |       |       |      |      |     |
| ermined |         |           |       |       |      |      |     |
| using   |         |           |       |       |      |      |     |
| the     |         |           |       |       |      |      |     |
| ass     |         |           |       |       |      |      |     |
| umption |         |           |       |       |      |      |     |
| of      |         |           |       |       |      |      |     |
| Recomme |         |           |       |       |      |      |     |
| ndation |         |           |       |       |      |      |     |
| ITU-R   |         |           |       |       |      |      |     |
| RA.769  |         |           |       |       |      |      |     |
| for a   |         |           |       |       |      |      |     |
| typical |         |           |       |       |      |      |     |
| spect   |         |           |       |       |      |      |     |
| rometer |         |           |       |       |      |      |     |
| channel |         |           |       |       |      |      |     |
| (3      |         |           |       |       |      |      |     |
| km/s).  |         |           |       |       |      |      |     |
|         |         |           |       |       |      |      |     |
| ^(3)^   |         |           |       |       |      |      |     |
| Int     |         |           |       |       |      |      |     |
| egrated |         |           |       |       |      |      |     |
| over    |         |           |       |       |      |      |     |
| the     |         |           |       |       |      |      |     |
| re      |         |           |       |       |      |      |     |
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| ba      |         |           |       |       |      |      |     |
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| with an |         |           |       |       |      |      |     |
| inte    |         |           |       |       |      |      |     |
| gration |         |           |       |       |      |      |     |
| time of |         |           |       |       |      |      |     |
| 2 000   |         |           |       |       |      |      |     |
| s.      |         |           |       |       |      |      |     |
+---------+---------+-----------+-------+-------+------+------+-----+

RESOLUTION 740 \[COM4/17\] (WRC-03)

Future compatibility analyses between the radio astronomy service\
and active space services in certain adjacent and nearby frequency bands

The World Radiocommunication Conference (Geneva, 2003),

considering

*a)* that adjacent or nearby primary service allocations have been made
to the radio astronomy service (RAS), and to various space services,
such as the fixed-satellite service (FSS), mobile-satellite service
(MSS), broadcasting-satellite service (BSS) and radionavigation
satellite service (RNSS), hereafter referred to as "active space
services";

*b*) that unwanted emissions from active space services may cause
unacceptable interference to the RAS;

*c)* that, for technical or operational reasons, the general limits in
Appendix **3** may be insufficient in protecting the RAS in specific
bands;

*d)* that, in many cases, the frequencies used by the RAS are chosen to
study natural phenomena producing radio emissions at frequencies fixed
by the laws of nature, and therefore shifting frequency to avoid or
mitigate interference problems may not be possible;

*e)* that Recommendation ITU‑R SM.1633 provides a list of band-pairs and
a methodology for conducting, and a framework for documenting the
results of, the compatibility studies between certain active and passive
services operating in specific adjacent and nearby band-pairs;

*f)* that it is necessary to ensure an equitable burden sharing for
achieving compatibility between active and passive services,

recognizing

*a)* that Recommendation ITU‑R SM.1633 addresses the compatibility
between the RAS and the active space services in specific band-pairs;

*b)* that the relevant annexes in Recommendation ITU‑R SM.1633 need
further refinement;

*c)* that measures beyond the general unwanted emission limits in
Appendix **3** may be required to protect the RAS from unwanted
emissions of active space services for the band-pairs listed in the
Table,

TABLE

Band-pairs to be considered for further studies

  ----------------- ------------------- -----------------------------------
  Space service     Space service       Radio astronomy service band
  band                                  

  MHz                                   MHz

  137-138           MSS                 150.05-153.0 (No. **5.208A**)
                    (space-to-Earth)    

  387-390           MSS                 322-328.6 (No. **5.208A**)
                    (space-to-Earth)    

  400.15-401        MSS                 406.1-410 (No. **5.208A**)
                    (space-to-Earth)    

  620-790\          BSS                 608-614
  (No. **5.311**)   (space-to-Earth)    
  see Resolution                        
  **\[COM4/5\]                          
  (WRC‑03)**                            

  1 452-1 492       BSS                 1 400-1 427
                    (space-to-Earth)\   
                    (non-GSO systems    
                    only)               

  1 525-1 559       MSS                 1 400-1 427
                    (space-to-Earth)\   
                    (non-GSO systems    
                    only)               

  1 525-1 559       MSS                 1 610.6-1 613.8
                    (space-to-Earth)\   
                    (non-GSO systems    
                    only)               

  1 559-1 610       RNSS                1 610.6-1 613.8
                    (space-to-Earth)    

  2 655-2 670       BSS                 2 690-2 700
                    (space-to-Earth)    

  2 655-2 670       FSS                 2 690-2 700
                    (space-to-Earth)\   
                    (Region 2)          

  2 670-2 690       FSS                 2 690-2 700
                    (space-to-Earth)\   
                    (Region 2)          

  GHz                                   GHz

  10.7-10.95        FSS                 10.6-10.7
                    (space-to-Earth)    

  21.4-22.0         BSS                 22.21-22.5
                    (space-to-Earth)    
  ----------------- ------------------- -----------------------------------

resolves

1 to invite ITU‑R to study the compatibility between the RAS and the
corresponding active space services as listed in the Table only, with a
view to updating or developing ITU‑R Recommendations, if appropriate;

2 that WRC‑07 should consider the results of the studies as identified
in *resolves* 1, in order to review and update, if appropriate, the
tables of threshold levels for consultation in the Annex to
Resolution **739 \[COM4/15\]** **(WRC‑03)**,

invites administrations

to actively participate in the ITU‑R studies identified in *resolves* 1
and to provide, where practicable, the relevant characteristics of
active and passive service systems operating in the bands identified in
the Table to this Resolution, as well as to indicate the impact on all
concerned services of implementing or not implementing the compatibility
solutions.

[^1]: **Author**: Rob Haines **Document Date**: November 26, 2003