# United States of America

## DRAFT PROPOSAL FOR THE WORK OF THE CONFERENCE

**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);**

**Background information:** In preparation for WRC--03, Task Group 1/7
conducted studies that led to the adoption of Recommendation ITU--R
SM.1633, which contains nine Annexes that, using the methodology
contained in the Recommendation, assess the compatibility of various
band pairs between the radio astronomy service and space services. Not
all studies in the Annexes were completed prior to WRC--03. On the basis
of Recommendation SM.1633 and associated studies, WRC-03 adopted
Resolutions **739** and **740**.

Resolution **739** contains guidance to administrations operating space
and radio astronomy stations in the band pairs contained in Tables 1-1
and 1-2, in order to come to acceptable solutions regarding space
station unwanted emissions at a radio astronomy station. The Resolution
includes a consultation process adopted at WRC-03 to assist
administrations in reaching mutually acceptable solutions when unwanted
emissions from space services exceed specified levels in certain radio
astronomy bands. The consultation process is included in Resolution
**739** and it will not be considered at WRC-07.

Resolution **740** calls for the completion of studies for the band
pairs indicated in its associated band-pair Table. Comprehensive studies
were needed to determine whether any of the band pairs from the Table of
Resolution **740** should be added to the tables in Resolution **739**,
taking into consideration the impact on all the concerned active and
passive services, and to determine the appropriate threshold levels for
consultation. In accordance with the *resolves 1* of the Resolution
**740**, only the band pairs listed in the Table of Resolution **740**
will be considered by WRC-07.

Studies have been conducted in TG 1/9 on a number of the band pairs
listed in Resolution **740,** and it is proposed at WRC-07 to add these
band pairs and values to Tables 1--1 and 1--2 of the Annex to Resolution
**739**. In a number of instances, unwanted emissions from existing NGSO
systems have been shown to not exceed the threshold levels. Systems with
unwanted emissions that exceed the thresholds, but that are already
operating, or that have been advanced published prior to the entry in
force of the Final Acts of, either WRC-03 or WRC-07, depending on the
band (see *resolves* 5 of the proposed draft revision of Resolution
**739**), are clearly grandfathered under the terms of Resolution
**739**, and are not subject to the consultation process.

Studies carried out in TG 1/9 have been documented in the appropriate
Annexes of ITU-R Recommendation SM.1633, and, for some satellite
systems, indicate levels of unwanted emissions in radio astronomy bands
that will not be exceeded.

Proposal:

**USA/ /1 (MOD)**

RESOLUTION 739 (REV. WRC‑07) Compatibility between the radio astronomy
service and the active\
space services in certain adjacent and nearby frequency bands The World
Radiocommunication Conference (Geneva, 2007),

**Reasons:** Editorial changes.

**USA/ /2 MOD**

*resolves*

5 that the space stations to be considered in the application of the
above *resolves* are:

a)  those designed to operate in the space service frequency bands
    listed in Table 1-1 of Annex 1 or in the band 1613.8-1626.5 MHz
    listed in Table 1-2 of Annex 1, and for which advance publication
    information was received by the Bureau following the entry into
    force of the Final Acts of WRC-03; and

b)  those designed to operate in all other space service frequency bands
    included in Table 1-2 of Annex 1, and for which advance publication
    information is received by the Bureau following the entry into force
    of the Final Acts of this conference;

**Reasons:** Following the pattern of the existing text, *resolves* 5 is
modified to indicate that space systems advance published before the
entry into force of the Final Acts of WRC--07 in the bands that are
being added to Res. **739** are not to be considered in the application
of *resolves* 1 to 3.

USA/ /3 (MOD)

ANNEX 1 TO RESOLUTION 739 (REV. WRC-07)

Unwanted emission threshold levels

**Reasons:** Editorial changes.

**USA/ /4 MOD**

TABLE 1-1

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

TABLE 1-2

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

**Reasons:** Studies in TG 1/9 have been completed on the band pairs and
values added to Tables 1--1 and 1--2, and they have been incorporated
into Recommendation ITU-R SM.1633. Since the 2690--2700 MHz radio
astronomy allocation is not used for spectral line observations, the
"NR" (no results available) notations in the appropriate rows of
Table 1--1 are changed to "NA" (not applicable) and the explanation for
"NR" is removed. The notes added to the Tables reflect compliance with
*resolves* 1 for some systems.

**USA/ /5 (MOD)**

RESOLUTION **740** (REV. WRC-07)

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

The World Radiocommunication Conference (Geneva, 2007),

**Reasons**: Editorial changes.

USA/ /6 MOD

considering

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

**Reasons**: Consequential to the removal of entries in the Table for
these services.

**USA/ /7 MOD**

recognizing

*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

                                        

                                        

                                        

                                        

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

                                        

                                        

                                        

  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)    

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

**Reasons:** Band pairs for which values were added to Tables 1--1
and 1--2 of Resolution **739** are eliminated from Resolution **740**.

**USA/ /8 MOD**

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;

**Reasons:** The Conference has completed consideration of these
studies.