------------------------------------------------ ----------------------------------------------------
  **World Radiocommunication Conference (WRC-07)\  ![](media/image1.png){width="1.9270833333333333in"
  Geneva, 22 October - 16 November 2007**          height="0.8125in"}

                                                   

                                                   

  **PLENARY MEETING**                              **Addendum 7 to Document 41-E**

                                                   **22 August 2007**

                                                   **Original: English**

  Asia-Pacific Telecommunity Administrations       

  COMMON proposals for the work of the conference  

  Agenda item 1.7                                  

                                                   
  ------------------------------------------------ ----------------------------------------------------

1.7 to consider the results of ITU-R studies regarding sharing between
the mobile-satellite service and the SRS (passive) in the band
1 668-1 668.4 MHz, and between the mobile-satellite service and the
mobile service in the band 1 668.4-1 675 MHz in accordance with
Resolution **744 (WRC‑03)**

### Introduction {#introduction .heading_b1}

Agenda item 1.7 addresses two issues related to the mobile-satellite
service (MSS) use of the band 1 668-1 675 MHz. Issue A relates to
sharing between mobile earth stations (MES) and systems in the space
research service (passive) (SRS (passive)) in the band 1 668-1 668.4
MHz. Issue B relates to sharing between the mobile service (MS) and the
MSS in the band 1 668.4-1 675 MHz.

APT Members are of the view that sharing study results between MSS and
SRS (passive) in the band 1 668-1 668.4 MHz and between MSS and MS in
the band 1 668.4-1 675 MHz conducted by ITU-R should be taken into
account in order to protect the services to which the bands are
currently allocated without any undue constrains on the MSS.

# 1 Issue A

### Introduction  {#introduction-1 .heading_b1}

Resolution **744 (WRC-03)**

invites ITU‑R

"1 to complete, as a matter of urgency and in time for WRC‑07, studies
relating to provisions to protect space research (passive) space
stations from harmful interference from mobile earth stations in the
band 1 668-1 668.4 MHz, taking care to avoid undue constraints on either
service;"

The band 1 668-1 668.4 MHz is allocated to the space research (passive)
service (SRS (passive)) and the mobile‑satellite service (MSS)
(Earth-to-space). The space research allocation may be used by
space-based radio astronomy applications, as part of space very large
baseline interferometry systems (S‑VLBI). A successful system ("HALCA")
operated in this band, but it is no longer operational. One other S-VLBI
system has been proposed for operation in this band ("Radioastron"). The
band 1 668-1 668.4 MHz is a part of the band, 1 660.5-1 668.4 MHz,
allocated to SRS (passive).

This band 1 668-1 668.4 MHz was allocated to the MSS at WRC-03. There
are no systems yet operating in the band, but about ten administrations
have made filings to the BR for MSS systems.

There is a potential for interference from the MES to the proposed
S-VLBI satellite and this has been studied in accordance with Resolution
744 (WRC-03).

APT would propose to adopt Method A1a of the CPM Report, whereby the
existing coordination trigger (based on frequency overlap) would be
complemented by a coordination threshold based on the e.i.r.p. of an MES
of 2.2 dB(W/4 kHz). This approach would consequently cap the protection
that would be provided to new SRS (passive) systems.

APPENDIX 5 (Rev.WRC‑03)

Identification of administrations with which coordination is to be
effected or\
agreement sought under the provisions of Article 9

TABLE 5-1     (Rev.WRC‑03)

Technical conditions for coordination\
(see Article 9)

**MOD** ASP/41A7/64

TABLE 5-1 (*continued*)     (Rev.WRC‑07)

+-----+-----------+-----------+-----------------+--------+-----------+
| R   | Case      | Frequency | Thre            | Calcul | Remarks   |
| efe |           | bands\    | shold/condition | ation\ |           |
| ren |           | (and      |                 | method |           |
| ce\ |           | Region)   |                 |        |           |
| of\ |           | of the    |                 |        |           |
| A   |           | service\  |                 |        |           |
| rti |           | for which |                 |        |           |
| cle |           | coor      |                 |        |           |
| 9   |           | dination\ |                 |        |           |
|     |           | is sought |                 |        |           |
+-----+-----------+-----------+-----------------+--------+-----------+
| No. | A station | Frequency | Bandwidths      | Check  |           |
| **9 | in a GSO  | bands for | overlap         | by     |           |
| .13 | satellite | which a   |                 | using  |           |
| **\ | network   | footnote  | For the band    | the    |           |
| GS  | in the    | refers to | 1               | as     |           |
| O/n | frequency | No.*      | 668-1 668.4 MHz | signed |           |
| on‑ | bands for | * 9.11A** | with respect to | frequ  |           |
| GSO | which a   | or No.    | MSS network     | encies |           |
|     | footnote  | **9.13**  | coordination    | and    |           |
|     | refers to |           | with SRS        | band   |           |
|     | No.       |           | (passive)       | widths |           |
|     | **9.11A** |           | networks, in    |        |           |
|     | or        |           | addition to     |        |           |
|     | No.       |           | bandwidth       |        |           |
|     | **9.13**, |           | overlap the     |        |           |
|     | in        |           | e.i.r.p. of an  |        |           |
|     | respect   |           | MES in an MSS   |        |           |
|     | of any    |           | network exceeds |        |           |
|     | other     |           | 2.2 dBW in a    |        |           |
|     | non-GSO   |           | reference       |        |           |
|     | satellite |           | bandwidth of    |        |           |
|     | network,  |           | 4 kHz           |        |           |
|     | with the  |           |                 |        |           |
|     | exception |           |                 |        |           |
|     | of        |           |                 |        |           |
|     | coo       |           |                 |        |           |
|     | rdination |           |                 |        |           |
|     | between   |           |                 |        |           |
|     | earth     |           |                 |        |           |
|     | stations  |           |                 |        |           |
|     | operating |           |                 |        |           |
|     | in the    |           |                 |        |           |
|     | opposite  |           |                 |        |           |
|     | direction |           |                 |        |           |
|     | of        |           |                 |        |           |
|     | tra       |           |                 |        |           |
|     | nsmission |           |                 |        |           |
+-----+-----------+-----------+-----------------+--------+-----------+
| . . |           |           |                 |        |           |
| .   |           |           |                 |        |           |
+-----+-----------+-----------+-----------------+--------+-----------+

**Reasons:** This procedure would provide adequate protection to the
planned SRS (passive) system without undue constraint to the MES. No
other SRS (passive) systems have been proposed or are foreseen.

# 2 Issue B

### Introduction  {#introduction-2 .heading_b1}

Resolution **744 (WRC-03)**

invites ITU‑R

"2 to study, as a matter of urgency and in time for WRC‑07, the use of
the band 1 668.4-1 675 MHz by the mobile service, and to complete any
relevant sharing studies between the mobile service and the MSS in this
band, taking care to avoid undue constraints on either service;"

The band 1 668.4-1 675 MHz is allocated to the MSS in the Earth-to-space
direction and the MS on a primary basis. There are two potential
interference scenarios:

1\) interference from transmitting stations in the MS to receiving space
stations in the MSS; and

2\) interference from transmitting MES to receiving mobile stations.

Regulatory provisions relating to Scenario 2 were dealt with at WRC-03
by the inclusion of a coordination mechanism and appropriate parameters
in RR Appendix 7. However, there are currently no regulatory provisions
which address potential interference from systems in the MS to MSS
systems in the band 1 668.4-1 675 MHz and hence the ITU sharing studies
have been focused on Scenario 1.

APT would support Method B2 whereby the use of the MS allocation would
be limited to transportable radio-relay systems (with the exception of
the territory of the administration included in the *resolves* of
Resolution 744 (WRC‑03)). Administrations would be encouraged to limit
the e.i.r.p. spectral density in the direction of the geostationary arc
to −27 dB(W/4 kHz) and this would encourage the transition of
transportable radio-relay systems to alternative frequency bands.

RR No. 5.380 could be suppressed, or it could be revised as shown below.

ARTICLE 5

Frequency allocations

Section IV -- Table of Frequency Allocations\
(See No. 2.1)

**MOD** ASP/41A7/65

**5.380** The band 1 800-1 805 MHz is intended for use, on a worldwide
basis, by administrations wishing to implement aeronautical public
correspondence. The use of the band 1 800-1 805 MHz is limited to
transmissions from aircraft stations.

**Reasons:** This modification would limit the use of the MS allocation
in the band 1 670-1 675 MHz to transportable-relay systems. There are no
known aeronautical public correspondence systems in the bands 1 670-1
675 MHz and 1 800‑1 805 MHz, and hence there are no apparent
consequences on existing services if RR No. 5.380 is modified.

**MOD** ASP/41A7/66

RESOLUTION 744 (Rev.WRC-07)

Sharing between the mobile-satellite service (Earth-to-space) and the
space\
research (passive) service in the band 1 668-1 668.4 MHz and between\
the mobile-satellite service (Earth-to-space) and the fixed and\
mobile services in the band 1 668.4-1 675 MHz

The World Radiocommunication Conference (Geneva, 2007),

\...

resolves

1 that the use of the band 1 668.4-1 675 MHz by systems in the mobile
service is limited to transportable radio-relay systems;

2 that administrations operating such systems should limit the e.i.r.p.
spectral density radiated in the direction of the geostationary arc to
--27 dB(W/4 kHz) in this band;

3 that, in the band 1 670-1 675 MHz, stations in the MSS shall not claim
protection from fixed and mobile stations operating in Canada and the
United States of America;

4 that *resolves* 1 and 2 do not apply to fixed and mobile stations
operating in Canada and the United States of America. **Reasons:** In
the band 1 668.4-1 675 MHz the revised Resolution would provide adequate
protection to the MSS systems without undue constraint to the MS
systems. It has been suggested in the CPM Report that Canada's name
could be added to the *resolves* of Resolution 744 (WRC‑03). On the
basis that the studies related to the two issues are complete, the
*invites ITU-R*, *invites administrations and interested parties* and
*recommends* in Resolution 744 (WRC-03) would no longer be required.

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_