#### Document IWG-3/009

**April 13, 2001**

**Informal Working Group 3 (IWG-3)**

**Preparation for WRC-03**

**DRAFT PRELIMINARY VIEW**

# **Agenda Item 1.34**: to review the results of studies in response to Resolution 539 (WRC-2000) concerning threshold values for non-GSO BSS (sound) in the band 2630-2655 MHz and to take action as required.

### 

### Issue

Should the provisional PFD thresholds in Resolution 539 be made
permanent or modified?

# **Background**

#  This agenda item is prompted by the provisions of a footnote, S5.418 adopted at WARC-92 and modified at WRC-2000, and actions taken at WRC-2000 that identified the band 2500-2690 MHz as an additional band for IMT-2000 systems. The referenced footnote provides for BSS (sound) systems in the band 2630-2655 MHz in the countries listed in the footnote, and exempts such type of systems from the PFD limits indicated in Table S21-4 of the Radio Regulations for BSS and FSS networks.

#  The lead group for development of CPM text is WP 6S (BSS). A very interested contributing group is WP 8F (IMT-2000). WP 6S has established SRG 6S/11 to prepare a report on the technical sharing issues.

There are a number of administrations which either have or are proposing
BSS and BSS (sound) systems for this band. These include India
(GSO/BSS), Malaysia (GSO/BSS (sound), Japan (NGSO/BSS/GSO (sound),
Indonesia (GSO/BSS), Canada (GSO/BSS), Vietnam (GSO/BSS), Saudi Arabia
(GSO/BSS), Tonga (GSO/BSS) and Brunei Darussalam (GSO/BSS). Indian and
Indonesian systems are already operational.

There have been a number of technical contributions to the SRG. It
appears that representatives of European countries support the use of
this band for IMT-2000 and are using very conservative assumptions to
advocate PFD threshold values which are significantly more restrictive
than those in S21-4. There is also the suggestion that these threshold
values should even be applied as hard limits. In WP-8F meetings there
has been particular disagreement between satellite and IMT-2000
advocates over what I/N value should be used as a protection criteria,
e.g., IMT-2000 proponents advocate an I/N of --10 dB and satellite
interests advocate an I/N of --6.0 dB or greater. The resultant PFD
threshold levels could effectively push BSS systems out of this band, a
situation which is to be avoided. It should be noted that the text of
footnote S5.384A reads "this identification (for IMT-2000) does not
preclude the use of these bands by any application of the services in
which they are allocated and does not establish priority in the Radio
Regulations." This concept is one that the US has strongly supported as
being essential in any bands identified for IMT-2000.

In many countries, including the US, studies are being performed to
determine the appropriate bands for the implementation of IMT-2000.
There are a number of incumbent services in this band that need to have
continued access to the spectrum. . For example, in the USA today there
exists extensive ITFS, MMDS, and two-way internet access fixed systems
using the band. Based on past experience, these services are adequately
protected by the existing PFD levels in Table S21-4.

## Preliminary View

1\. The use of the band 2630 - 2655 MHz by IMT-2000 systems should not
preclude the use of this band by any application of the services to
which they are allocated and no radio service should have priority over
other services also allocated on a primary basis in this band.

2\. The PFD threshold values for non-GSO BSS (sound) systems in the band
2630-2655 MHz should be maintained at the levels indicated in Resolution
539 unless ITU-R Recommendations demonstrate a need to change them
consistent with View #1 above.

3\. Existing satellite networks (i.e., those for which Coordination or
Notification information has been provided to the ITU) should not be
subject to more restrictive PFD threshold values or limits than those
currently in Resolution 539 and S21-4, and any changes in these limits
must not be applied retroactively to these existing satellite networks.

4\. Any attempt to extend more restrictive PFD threshold values or
limits to other parts of the band should be resisted.

(04.13.01)

IWG-3-009 4-13-01