+--------------------------------------------+-------------------------+
| **Radiocommunication Study Groups**        | ![](                    |
|                                            | media/image1.png){width |
|                                            | ="1.9270833333333333in" |
|                                            | height="0.8125in"}      |
+--------------------------------------------+-------------------------+
|                                            |                         |
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|                                            |                         |
+--------------------------------------------+-------------------------+
| Source: Document 5-6/TEMP/27               | **Annex 8 to\           |
|                                            | Document 5-6/53-E**     |
| Subject: WRC-11 Agenda item 1.17,          |                         |
| Resolution 749 (WRC-07), Circular Letter   |                         |
| CA/171                                     |                         |
+--------------------------------------------+-------------------------+
|                                            | **19 November 2008**    |
+--------------------------------------------+-------------------------+
|                                            | **English only**        |
+--------------------------------------------+-------------------------+
| Annex 8 to Joint Task Group 5-6 Chairman's |                         |
| Report                                     |                         |
+--------------------------------------------+-------------------------+
| Note from Chairman JTG 5-6 to chairman of  |                         |
| Working Party 3K                           |                         |
+--------------------------------------------+-------------------------+
| Propagation models needed for use in       |                         |
| sharing studies\                           |                         |
| at UHF frequencies                         |                         |
+--------------------------------------------+-------------------------+

At its second meeting held in Geneva 4-10 November 2008, JTG 5-6
discussed various aspects related to the sharing of mobile services with
other services allocated on a primary basis in the band 790-862 MHz.

Joint Task Group 5-6 has developed preliminary draft methodologies
(including interference objectives) for sharing studies between the
mobile service, on the one hand, and the terrestrial broadcasting, fixed
and aeronautical radionavigation services, on the other hand, in the
band 790‑862 MHz.

Input contributions to JTG 5-6 suggested a propagation model based on
elements of the ITU-R Recommendation P.1546-3 and the Okumura-Hata model
(Report ITU-R SM.2028) to address sharing studies between the
broadcasting and the mobile services (see Appendix A of Annex 1 of
Document 5-6/53, Annex 7).

Joint Task Group 5-6 kindly requests the advice of WP 3K on the
appropriate propagation models to be used in sharing and compatibility
studies between systems in the mobile service and systems of other
services in the band 790-862 MHz.

JTG 5-6 also kindly requests that WP 3K provides details on the most
appropriate building penetration loss figures applicable to the band
790-862 MHz to allow the best unified approach to these sharing studies
(see Tables 4.1 -- 4.3 and 4.6 -- 4.7 of Annex 1 of Document 5-6/53,
Annex 7).

Joint Task Group 5-6 would appreciate any comments WP 3K (or the WP 3K
Chairman) can provide on these issues as soon as possible noting that
JTG 5-6 must commence its sharing and compatibility studies in the near
future so that preliminary results can be available at its next meeting
to be held in Geneva, Switzerland, 11-15 May 2009.

Joint Task Group 5-6 thanks WP 3K for its consideration of these
matters.

**Status**: For action

**Contact**: Roland Beutler (JTG 5-6 SWG2 Chairman)

**Attachment:** Document 5-6/53, Annex 7
(<http://www.itu.int/md/R07-JTG5.6-C-0053/en>)