# United States of America

## DRAFT PROPOSAL FOR THE WORK OF THE CONFERENCE

**Agenda Item 1.9:** to review the technical, operational and regulatory
provisions applicable to the use of the band 2 500-2 690 MHz by space
services in order to facilitate sharing with current and future
terrestrial services without placing undue constraint on the services to
which the band is allocated;

**Background Information:**

**Issue A: Necessary Power Flux Density Limits**

There are three space services allocated in portions of the 2 500-2 690
MHz band. In addition to MSS there are allocations to BSS and FSS. At
WRC-03 the issue of sharing between terrestrial services and BSS (Sound)
was resolved as reflected in RR Nos. **5.417A** and/or **5.418**. The
sharing between BSS and terrestrial services not included in these two
provisions was not addressed at WRC-03 and need to be considered. WRC-03
recognized the need review the technical, operational and regulatory
provisions applicable to the use of the band 2 500-2 690 MHz by space
services in order to facilitate sharing with current and future
terrestrial services (see Res. **802 (WRC-03**), Agenda Item 1.9). To
that end, CPM06-1 established the Joint Task Group 6-8-9 (JTG 6-8-9)
with the purpose to conduct studies on this issue. The JTG 6-8-9 has
developed a methodology for estimating the satellite pfd values required
to protect terrestrial services. Based on this methodology, the USA has
determined that pfd values at the surface of the Earth produced by the
emissions of MSS, BSS and FSS satellites of -136 dBW/m^2^/MHz for angles
of arrival below 5 and -122 dBW/m^2^/MHz for angles of arrival greater
than 25 would yield tolerable levels of interference to the Fixed and
non IMT-2000 mobile services.

There are definite advantages to having a uniform regulatory regime for
all space services in the 2 500-2 690 MHz band, based on the
specification of a power flux density limits in RR **Article 21**. First
it would ensure long term safeguard of terrestrial systems in the band
2 500-2 690 MHz from satellite interference and could also be beneficial
to the long-term development of space services as a defined set of pfd
limits would be established and finalized. Additionally, a hard limit
regulatory regime would alleviate coordination burden and provide
regulatory certainty to all services in the band.

In short, the proposed regulatory approach would ensure that existing
and planned satellite networks are not overly constrained while existing
and future terrestrial services are adequately protected.

**Issue B: Mobile Satellite Service (MSS)**

The band 2 500-2 520 MHz is allocated to MSS (space-to-Earth) paired
with MSS (Earth-to-space) allocation in the band 2 670-2 690 MHz.[^1]
The terrestrial services in these bands include the Mobile and the Fixed
Services (including IMT-2000). Both the terrestrial Mobile and Fixed
Services have been rapidly evolving to encompass high-speed mobile
Internet services requiring sensitive receiving equipment, which may be
highly susceptible to interference.

In general, co-frequency sharing between MSS and terrestrial services
has been found to be difficult by the ITU-R studies. The SG-8, for
example, studied the feasibility of sharing between MSS and MS for
IMT-2000 and concluded that co-frequency/co-coverage sharing is not
feasible. A new regulatory provision is proposed that would limit MSS
downlinks in the 2 500-2 520 MHz band to national and regional systems
only. Under the proposed regulatory provision, administrations seeking
to implement MSS will be allowed to do so while other administrations
will be able to implement terrestrial services, all without the undue
regulatory constraints. In case of a national system, the service area
of the MSS system would be limited to the territory under the
jurisdiction of the notifying administration. In case of a regional
system, the following Radio Regulations Board's decisions would
apply[^2]:

(1) No. **5.2.1** applies to the interpretation of the word "regional"
    without a capital "R".

(2) When an administration submits a coordination request for a service
    area that covers its national territory and extends beyond it, the
    responsible administration, before it notifies the relevant
    assignments under Article **11**, will have to obtain agreements
    from those administrations whose territories are included in the
    service area. When the responsible administration notifies these
    assignments under Article **11**, it shall submit the list of
    administrations that agreed to form the regional system and shall
    adjust the service area accordingly. If no agreement is obtained,
    the service area shall be limited to its national territory.

It is also important to note that this rule of procedure clearly
stipulates that the service area of a national or regional satellite
system does not extend beyond the territory of administration(s) that
agreed to be included in that service area.

**Proposals associated with Issue A:**

USA/ /1 MOD

ARTICLE 21

TABLE 21-4     (WRC-03)

**Reasons:** Studies have shown that a satellite pfd value of -136
dBW/m^2^/MHz at angles below 5, and -122 dBW/m^2^/MHz at angles greater
than 25 yielded acceptable levels of interference to terrestrial
services in the 2500-2690 MHz band. The proposed power flux density
limits would facilitate FSS, BSS and MSS sharing with current and future
terrestrial services in the band 2500-2690 MHz and provide necessary
safeguard for the terrestrial (FS and MS) systems in the band. The
proposed modification would also provide regulatory certainty to
satellite services as a defined set of pfd limits would be known and
extensive coordination with uncertain outcome would not be required.

USA/ /2 MOD

**APPENDIX 5 (Rev. WRC-03)**

**ANNEX 1**

TABLE 5-2     (WRC-03)

+----------+----------+------------+-----+------------+-----+--------+
| F        | Ter      | Co         |     |            |     |        |
| requency | restrial | ordination |     |            |     |        |
| band\    | service\ | threshold  |     |            |     |        |
| (MHz)    | to be    | values     |     |            |     |        |
|          | p        |            |     |            |     |        |
|          | rotected |            |     |            |     |        |
+==========+==========+============+=====+============+=====+========+
|          |          | GSO space  |     | Non-GSO    |     |        |
|          |          | stations   |     | space      |     |        |
|          |          |            |     | stations   |     |        |
+----------+----------+------------+-----+------------+-----+--------+
|          |          | pfd\       |     | pfd\       |     | \%     |
|          |          | (per space |     | (per space |     | FDP\   |
|          |          | station)\  |     | station)\  |     | (in 1  |
|          |          | c          |     | c          |     | MHz)\  |
|          |          | alculation |     | alculation |     | (NOTE  |
|          |          | factors\   |     | factors\   |     | 1)     |
|          |          | (NOTE 2)   |     | (NOTE 2)   |     |        |
+----------+----------+------------+-----+------------+-----+--------+
|          |          | *P*        | *r  | *P*        | *r  |        |
|          |          |            | * d |            | * d |        |
|          |          |            | B/\ |            | B/\ |        |
|          |          |            | d   |            | d   |        |
|          |          |            | egr |            | egr |        |
|          |          |            | ees |            | ees |        |
+----------+----------+------------+-----+------------+-----+--------+
| ~~2 500  | ~~A      | ~~-- 146   | ~   | ~~-- 146   | ~   |        |
| -2 520~~ | nalogue\ | dB(W/m2)\  | ~0. | dB(W/m2)\  | ~0. |        |
|          | FS       | in 4 kHz   | 5~~ | in 4 kHz   | 5~~ |        |
|          | tel      | and\       |     | and\       |     |        |
|          | ephony~~ | -- 128     |     | -- 128     |     |        |
|          |          | dB(W/m2)\  |     | dB(W/m2)\  |     |        |
|          | ~~(NOTE  | in 1 MHz~~ |     | in 1 MHz~~ |     |        |
|          | 5)~~     |            |     |            |     |        |
+----------+----------+------------+-----+------------+-----+--------+
|          | ~~All    | ~~-- 128   | ~   | ~          | ~   | ~~25~~ |
|          | other    | dB(W/m2)\  | ~0. | ~-- 128 dB | ~0. |        |
|          | cases~~  | in 1 MHz~~ | 5~~ | (W/m2)\    | 5~~ |        |
|          |          |            |     | in 1 MHz~~ |     |        |
+----------+----------+------------+-----+------------+-----+--------+
| ~~2 520  | ~~A      | ~~-- 154   | ~~7 | ~~-- 146   | ~   |        |
| -2 535~~ | nalogue\ | dB(W/m2)\  | 5~~ | dB(W/m2)\  | ~0. |        |
|          | FS       | in 4 kHz   |     | in 4 kHz   | 5~~ |        |
|          | tel      | and\       |     | and\       |     |        |
|          | ephony~~ | -- 136     |     | -- 128     |     |        |
|          |          |  dB(W/m2)\ |     | dB(W/m2)\  |     |        |
|          | ~~(NOTE  | in 1 MHz~~ |     | in 1 MHz~~ |     |        |
|          | 5)~~     |            |     |            |     |        |
+----------+----------+------------+-----+------------+-----+--------+
|          | ~~All    | ~~-- 136   | ~~  | ~~-- 128   | ~   | ~~25~~ |
|          | other    | dB(W/m2)\  | 0.7 | dB(W/m2)\  | ~0. |        |
|          | cases~~  | in 1 MHz~~ | 5~~ | in 1 MHz~~ | 5~~ |        |
+----------+----------+------------+-----+------------+-----+--------+

**Reasons:** Consequential to adding pfd limit for MSS to Article
**21**, Table 21-4 per USA/ /1. Limits in Article **21** eliminate the
requirement for coordination with terrestrial systems in the band
2 500-2 535 MHz.

**Proposals associated with Issue B:**

USA/ /3 MOD

ARTICLE 5

Frequency allocations

Section IV -- Table of Frequency Allocations

2 500-2 520 MHz

+----------------------+----------------------+-----------------------+
| Allocation to        |                      |                       |
| services             |                      |                       |
+----------------------+----------------------+-----------------------+
| **2 500-2 520**      | **2 500-2 520**      | **2 500-2 520**       |
|                      |                      |                       |
| FIXED 5.409 5.410    | FIXED 5.409 5.411    | FIXED 5.409 5.411     |
| 5.411                |                      |                       |
|                      | FIXED-SATELLITE      | FIXED-SATELLITE       |
| MOBILE except        | (space-to-Earth)     | (space-to-Earth)      |
| aeronautical mobile  | 5.415                | 5.415                 |
| 5.384A               |                      |                       |
|                      | MOBILE except        | MOBILE except         |
| MOBILE-SATELLITE\    | aeronautical mobile  | aeronautical mobile   |
| (space-to-Earth)     | 5.384A               | 5.384A                |
| 5.351A 5.403         |                      |                       |
|                      | MOBILE-SATELLITE     | MOBILE-SATELLITE      |
|                      | (space-to-Earth)     | (space-to-Earth)      |
|                      | 5.351A 5.403 [ADD    | 5.351A 5.403          |
|                      | 5.AAA]{.underline}   |                       |
+----------------------+----------------------+-----------------------+
| 5.405 5.407 5.412    | 5.404 5.407 5.414    | 5.404 5.407 5.414     |
| 5.414                | 5.415A               | 5.415A                |
+----------------------+----------------------+-----------------------+

USA/ /4 ADD

**5.AAA** The use of the band 2 500-2 520 MHz by the mobile-satellite
service is limited to national and regional systems, subject to
agreement obtained under No. **9.21**.     

**Reasons:** Restricting MSS to national and regional systems would
further facilitate sharing between MSS and terrestrial services. This
restriction would not constrain MSS, as there are no global coverage
systems planned for this band, but would ensure that MSS systems service
areas are limited to territories of the administrations seeking to
implement MSS. This restriction, however, would not fully address the
issue of MSS interference to terrestrial systems and must be implemented
in conjunction with the appropriate PFD limits for MSS (see proposed
modifications to Article **21**).

[^1]: In accordance with RR **5.403**, the band 2 520-2 535 MHz may also
    be used for MSS (space-to-Earth) for operation limited to within
    national boundaries.

[^2]: See comments under the Rules of Procedure concerning No. **5.415**
    and **5.416**