### United States of America

### DRAFT PROPOSAL FOR THE WORK OF THE CONFERENCE

**Agenda Item 1.4**: to consider the results of studies related to
**Resolution 114 (WRC-95)**, dealing with the use of the band
5 091-5 150 MHz by the fixed-satellite service (Earth-to-space) (limited
to non-GSO MSS feeder links), and review the allocations to the
aeronautical radionavigation service and the fixed-satellite service in
the band 5 091-5 150 MHz;

**Background Information**: The frequency band 5 000-5 250 MHz is
allocated on an international basis to the aeronautical radionavigation
service (ARNS). Currently only the 5 030-5 150 MHz portion has a defined
ARNS function; namely the microwave landing system (MLS), with only the
5 030-5 091 MHz portion containing defined MLS channels. However, the
International Civil Aviation Organization (ICAO) has identified the band
5 091-5 150 MHz for expansion for MLS. In addition, the aviation
community is exploring other applications in the 5 091 ‑ 5 150 MHz band.
The fixed satellite service (FSS) (Earth-to-space), limited to
non-geostationary (non-GSO) mobile-satellite service (MSS) feeder links,
is also allocated to the band 5 091-5 150 MHz in accordance with
**5.444A**. Also, FSS is allocated on a primary (Earth-to-space) in the
band 5 150-5 250 MHz for the use of feeder uplinks for non-GSO MSS
systems (**5.447A**). The 5 091-5 150 MHz band was allocated on a
co-primary basis to the FSS for NGSO MSS feeder uplinks under **5.444A**
with the conditions that:

-   prior to 1 January 2010, the use of the band 5 091-5 150 MHz by
    feeder links of non-geostationary-satellite systems in the
    mobile‑satellite service shall be made in accordance with
    Resolution **114 (WRC-95)**;

-   prior to 1 January 2010, the requirements of existing and planned
    international standard systems for the aeronautical radionavigation
    service which cannot be met in the 5 000-5 091 MHz band, shall take
    precedence over other uses of this band;

-   after 1 January 2008, no new assignments shall be made to stations
    providing feeder links of non-geostationary mobile-satellite
    systems;

-   after 1 January 2010, the fixed-satellite service will become
    secondary to the aeronautical radionavigation service.

Two MSS systems have implemented spacecraft tracking and control
operations and one system has begun commercial service using the 5 091
-- 5 150 MHz band for transmitting communications traffic, as well as,
command signals, from gateway earth stations to the non-GSO spacecraft.
These systems are successfully coexisting with the ARNS. Furthermore,
civil aviation has not expanded its use to the band 5 091 ‑ 5 150 MHz
for MLS. ICAO is looking at alternatives to the instrument landing
system (such as greater MLS implementation) before an all-weather Global
Navigation Satellite System capability is available. There has been
successful coordination between the FSS and ARNS based on Recommendation
ITU-R **S.1342**, \"Method for determining coordination distances, in
the 5 GHz band, between the international standard microwave landing
system in the aeronautical radionavigation service and non-geostationary
mobile satellite service stations providing feeder uplink services.\"
These studies showed that compatibility between MLS receivers and MSS
feeder links (Earth-to-space) could exist if sufficient geographical
separation exists between the two stations. As a result, Recommendation
ITU-R **S.1342** was adopted to trigger coordination between the two
operators to determine the acceptability of an MSS site, possibly with
or without restrictions.

**Proposal**:

**USA/ /1**

#### NOC

##### 5.444

**Reasons**: The allocations and conditions specified in the footnote
are sufficient to accommodate both the ARNS and FSS for the foreseeable
future.

**USA/ /2**

**[NOC]{.underline}**

**5.444A**

**Reasons:** The allocations and conditions specified in the footnote
are sufficient to accommodate both the ARNS and FSS for the foreseeable
future.

**USA/ /3**

**MOD**

**RESOLUTION 114 (WRC-03)**

Use of the band 5 091-5 150 MHz by the fixed-satellite service
(Earth-to-space) (limited to feeder links of the non-geostationary
mobile-satellite service)

**Reasons**: Editorial

resolves

1 that the provisions of this Resolution and of Nos. **5.444** and
**5.444A** shall enter into force on 18 November 1995;

2 that administrations authorizing stations providing feeder links for
non-GSO mobile-satellite systems in the frequency band 5 091-5 150 MHz
shall ensure that they do not cause harmful interference to stations of
the aeronautical radionavigation service;

**USA/ /4**

**MOD**

3 that the allocation to the aeronautical radionavigation service and
the fixed-satellite service in the frequency band 5 091-5 150 MHz should
be reviewed at a future competent WRC,

**Reasons**: The dates in the resolution are obsolete. By changing the
date to a future competent WRC leaves the option to consider the sharing
of the band between MSS feeder links and ARNS at an appropriate time.

urges administrations

1 when authorizing stations of the aeronautical radionavigation service,
to assign frequencies giving priority to the band below 5 091 MHz;

2 when assigning frequencies in the band 5 091-5 150 MHz before
1 January 2010 to stations of the aeronautical radionavigation service
or to stations of the fixed-satellite service providing feeder links of
the non-GSO mobile-satellite service (Earth-to-space), to take all
practicable steps to avoid mutual interference between them,

instructs ITU-R

1 to study the technical and operational issues relating to sharing of
this band between the aeronautical radionavigation service and the
fixed-satellite service providing feeder links of the non-GSO
mobile-satellite service (Earth-to-space);

**USA/ /5**

**MOD**

2 to bring the results of these studies to the attention of a future
competent WRC,

**Reasons**: The dates in the resolution are obsolete. By changing the
date to a future competent WRC leaves the option for instructing the
ITU-R to study the sharing of the band between MSS feeder links and ARNS
at an appropriate time.