# United States of America

### PROPOSAL FOR THE WORK OF THE CONFERENCE

**Agenda Item 1.7**: to consider the results of ITU-R studies regarding
sharing between the mobile-satellite service and the space research
service (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)**;

**Background Information**: **(Issue A)** 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 Long Baseline Interferometry systems (S-VLBI). The
band 1 668-1 668.4 MHz is a part of the band, 1 660.5-1 668.4 MHz,
allocated to the SRS (passive). However S-VLBI spaceborne receivers
typically receive over a wider frequency band because a wider band is
desirable for increasing the sensitivity of systems and also to observe
highly red-shifted objects.

The potential for interference from mobile earth stations (MES)
operating in the MSS to the S-VLBI systems has been studied by the
ITU-R, in accordance with Resolution **744**. The studies concluded that
to ensure protection of future SRS (passive) systems operating in highly
elliptical orbits, with an apogee of 150 000 km and higher, the power
density of MESs operating in the GSO MSS networks should not exceed to
-- 12.5 dBW/4 kHz in any part of the frequency band 1 668-1 668.4 MHz.

**(Issue B)** The band 1 668.4-1 675 MHz is allocated to the fixed and
mobile services on a primary basis. The WRC-03 allocated to MSS the
bands 1518-1525 MHz (space-to-Earth) and 1 668.4-1 675 MHz
(Earth-to-space). In allocating the band 1668.4-1675 MHz to the MSS, the
WRC-03 recognized that this allocation cannot be used in the United
States. Specifically, the WRC-03 recognized that constraints on the MSS
in the corresponding downlink band 1518-1525 MHz (see RR 21.16 and
5.348B) preclude the feasibility of using the 1668-1675 MHz for MSS
uplinks in the United States. The WRC-03 further recognized that the
United States intends to implement systems in the existing fixed and
mobile allocation in the 1668-1675 MHz and that these systems must not
be constrained by the new MSS allocation. To that end, the WRC-03
adopted Resolution 744 (WRC-03). In accordance with the *recommends* of
Resolution 744 (WRC-03), the studies conducted under this resolution did
not consider sharing between MSS and mobile services in the United
States.

The United States therefore, proposes to maintain the *resolves* of
Resolution 744 as adopted at WRC-03.

**Proposal**:

USA/ /1 ADD

**5.379\[F\]** In order to protect the space research service (passive)
in the band 1 668-1 668.4 MHz the maximum emission power density of any
mobile earth station in a mobile-satellite service network in the
geostationary satellite orbit network operating in this band, shall not
exceed -12.5 dBW/4 kHz in any part of the frequency band 1 668-1 668.4
MHz.

**Reasons**: To ensure the protection of and future S-VLBI systems
operating in the SRS (passive).

**USA/ /2 MOD**

**5.379D** For sharing of the band 1 668-1 675 MHz between the
mobile-satellite service and the fixed, and mobile services,
Resolution **744 (WRC‑03)** shall apply.     (WRC-03)

**Reasons**: Studies under Res. **744** have concluded with regard to
the SRS (passive).

USA/ /3 MOD

RESOLUTION 744 (WRC-~~03~~[07]{.underline})

Sharing 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),

Considering

a\) that WRC-03 has made a global allocation to the mobile-satellite
service (MSS) (Earth-to-space) in the band 1 668-1 675 MHz and a global
allocation to the MSS (space-to-Earth) in the band 1 518-1 525 MHz;

b\) that due to sharing conditions between MSS (space-to-Earth) and the
aeronautical mobile service for telemetry in the band 1 518-1 525 MHz
(see No. **5.348B**), MSS operation in the United States is unlikely to
be feasible;

c\) that the above constraints on the MSS in the band 1 518-1 525 MHz
therefore limit the possible use of the band 1 668-1 675 MHz by the MSS
in the United States;

d\) that the band 1 660.5-1 668.4 MHz is allocated to the space research
(passive) service;

e\) that the band 1 670-1 675 MHz is use in the United States for the
fixed and mobile services,

considering further

a\) that the band 1 668.4-1 675 MHz is allocated to the fixed and mobile
services;

resolves

that, in the band 1 670-1 675 MHz, stations in the MSS shall not claim
protection from fixed and mobile stations operating within the United
States,

**Reasons**: The studies called for in Resolution 744 (WRC-03) have been
completed. No further action is required.

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