Ninth Meeting Of The Broadband Fixed Wireless Access Technical Sub Group Held At 1 Victoria Street On 9th February 2001

Barry Lewis Chairman RA

Jim Nixon RA

Peter Jessup RA

Nichola Watts Secretary

List of all those present at Annex A

1. Apologies

Graham MacDonald (Nortel Networks), Helen Hicks (Oftel), Mike Crowther (Kingston Communications), Arthur Christian (Hughes Network Systems Limited), David Palmer (Ensemble Communications), Barry Goodyear (RA)

2. Minutes of the Eighth Meeting (BFWAtg(00)52)

The minutes of the previous meeting were agreed, without amendment.

2.1 Matters Arising

The group needs to remain informed of CEPT/ITU-R developments regarding the 40GHz band. FM34 have started work on high density fixed service bands (which includes the 40GHz band) and are due to meet 8-9 March 2001. Action: Ongoing-RA

The Inter-operator co-ordination guidelines action was covered under Agenda item 5, which was originally item 4.

At the last Technical Group meeting, the issue of adjacent area/ adjacent frequency block interference was raised. Mr Lewis had circulated document BFWAtg(00)53 which considered receiver NFD and PFD at the service area boundary. Calculations show that any interference would be below the noise floor. Action closed.

3. 42.5-43.5 GHz – BFWA/Radio-Astronomy (BFWAtg(01)01, 02 and 03)

A BFWAtg Member (Transfinite Systems Ltd) presented the following work to the group; "Re-examination of the protection requirements for the Radio Astronomy Service (RAS) in light of the BFWA Multimedia Wireless Systems proposed for the 42.5 - 43.5 GHz frequency band".

Mr Lewis explained that RA (under the auspices of the Technical Forum) had commissioned Transfinite to carry out this work and the following presentation supports their final report to the RA. The full report can be found on the Agency’s website in the BFWAtg area.

A BFWAtg Member said that to limit the work to reasonable proportion and in consultation with RA the work focused on 17 models. He explained their modelling assumptions which included the following:

Analysis of BFWA sharing with RAs based on ITU-R Recommendations.

Based on P.452 propagation model.

Realistic antenna heights for both BFWA and RAs

Based upon aggregate interference from all potential interfering transmitters.

The calculation of aggregate interference need not include transmitters at a distance of more than 110 km from the RAs site.

Accurate modelling of interference from BFWA into RAs should also include the impact of terrain on propagation loss.

He continued to explain their methodology and the results of their initial runs.

A BFWAtg Member highlighted the following "top level" conclusions;

The ERC report 36 recommended exclusion zone of 50 km, was insufficient to protect the RAs

New methodology to calculate aggregate interference requires ratification.

Exclusion zones could usefully be defined as multiple zones which improve potential BFWA coverage without requiring mitigation everywhere.

Multiple zone boundaries based on Rec.452 loss figures based on 10% of time criteria.

The characteristics of RAs operating in this band will determine the extent for which BFWA can be deployed.

Areas for further study were confirmation of the types of observation the RAs would make in 40 GHz band and the average gain pattern of RAs antennas towards the horizon.

A BFWAtg Member expressed an opinion that the report’s conclusions depended strongly on Transfinites’ assumptions about both RAs and BFWA parameter values and that he would like to make a number of comments. Mr Lewis said that bearing in mind the plan to widen the audience for this work, he would welcome any issues that were raised and he pointed out that in the first instance RA’s Fixed Service task group would be made aware of the propagation issues.

The intention was to feed this work into SE19 as the first step to gaining wider acceptance of the methodologies proposed and in preparation for agenda item 1.32 of the next WRC.

A BFWAtg Member, representing the RAs, mentioned activities drafting new ITU-R Recommendations that addressed the protection criteria for RAs Again, Mr Lewis welcomed consideration by the RAs in preparation for wider consideration of the work and invited the BFWA member and others to comment in the next few weeks. Action: Members

4. P-P Systems at 28 GHz; Interface Requirements (BFWAtg(01)03)

Consistent with the policy of not excluding the use of point-to-point links in the 28 GHz BFWA band for either BFWA service backhaul or access, a new Interface Requirement (IR) was drawn up.

Mr Jessup/Mr Nixon presented the IR for Point-to-Point licensing. The wording of sections 1 and 2 was essentially the same as that in the Point-to-Multipoint IR. Tables 1 and 2, however, relate to standards for point-to-point equipment. The more stringent (class 2) antenna was selected for operation in the BFWA band for reasons stated in the antenna specification (ETS 300 833).

Only one comment was received from Mr Lewis who suggested that note 3 in table 2.1 should be relating to EIRP for issues on coexistence, rather than power. It was agreed this could be altered. The revised document would be circulated for comments and will be presented to the EU in two weeks. Action: Mr Jessup to revise document and Members to provide comments within two weeks.

5. Inter-Operator Co-ordination Guidelines (BFWAtg(00)47 Rev 3)

There were no comments from the Technical Group on revision 2 of the document. Mr Lewis made some amendments to revision 2 and presented them as follows:

"and should be enhanced as operational experience is gathered." was added in section 1.

"where appropriate to monitor" was removed from section 4. "addressing both national and…" was also added with regard to policy issues.

Very minor editorial modification was made to section 4.2.2.

In section 6, square brackets were removed from the highlighted text.

Section 7 was a new section, which had been added to convey the importance of EIRP for BFWA co-ordination. Recommended maximum EIRP levels have also been given in this section. A BFWAtg Member recommended "with ATPC activated" had no relevance and should be removed. This action was agreed. A BFWAtg Member questioned the need to define maximum EIRP when the PFD was already specified at the service boundary edge. However, it was decided it was important that it was specified for the benefit of other operators co-existing inside the service area boundary.

Minor changes were made to section 8 to improve the clarity. A BFWAtg Member suggested "with" was replaced with "between" in the first paragraph of section 8.1 to improve clarity. Mr Lewis had also added a clause to clarify the boundary PFD requirements along a coastline.

Considerations for PP systems have been included.

An additional note was added to section 8.2.1 to stress the need for further investigation of the coexistence of systems that use different architectures.

Again, A BFWAtg Member suggested the change of wording from "with" to "between" in Annex A.

Annex B had minor changes. The PFD needed to be verified at the service area boundary using the planning tool used by the RA. Action – Mr Nixon/Mr Jessup.

Further investigation into the effect of 25 dB ATPC at the service boundary is also required for Annex C. Action – Mr Nixon.

The technical group was happy to see this document published as a version 1.0 RA publication on the basis of this discussion.

6. Frequency Allocation Plan for 40 GHz (BFWAtg(00)14 Rev 4)

It was anticipated that this document would conclude its development at the next SE19 meeting. Therefore, this was the final opportunity for group members to comment. A BFWAtg Member commented on Annex 1 as follows:

The tone of the annex seems biased towards assignment plans for symmetric FDD systems. He disagreed with certain points regarding the viability of the plans for TDD systems. He agreed to draft some wording to try and redress the balance that could be used as a basis for an input to SE19. Action BFWAtg Member

Mr Nixon pointed out that the proposed assignment plans could have implications on spectrum packaging, and therefore this must be highlighted to the Consultation Group.

The group looked at annexes 2, 3 and 4. Any issues relating to these needed to be presented to Mr Lewis before the next SE19 meeting. Action: Members

A BFWAtg Member presented this document to the group. Other than the "Block Edge Mask" issue (being dealt with also in SE19-see BFWAtg(00)14 rev4), this document was relatively stable.

A BFWAtg Member questioned the –80dBW/MHz out of block limits in relation to protection of the spectrum used by the Radio Astronomy Service (RAs). A BFWAtg Member replied that it was a limit taken from other ETSI specifications, but did not know if there were any implications to the RAs band.

8. Way ahead for 40 GHz (Tech Group perspective) (BFWAtg(01)05)

Mr Lewis asked the group for their opinion of suitable progress in which to inform the Consultation Group. It was decided a carefully worded document could be put to the Consultation Group, outlining technical progress and the need for a clear plan for the licensing of the 40 GHz band.

This document is to be approved by the Technical Group by correspondence before presentation to the Consultative Group. Action – Mr Lewis

9. DONM

The tenth meeting will be held at 10.30am on Tuesday 8th May 2001 at DTI 1 Victoria Street.

As many members of the BFWAtg are aware I shall be resigning from the Agency on 23^rd February 2001 and as a result will be relinquishing the chairmanship of this group. I would like therefore, to take this opportunity to thank the members of the BFWAtg for their support and input to the activities of this group supporting its role of advising the BFWA consultation group. I would like to wish the group continued success under new chairmanship.

Regards

Barry Lewis

Annex A