Fourth Meeting Of The Broadband Fixed Wireless Access Technical Sub Group Held At Wyndham House On 23 May 2000

Those present:

Barry Lewis Chairman RA
Nichola Watts Secretary RA
Jim Nixon RA
List of all those present at Annex A

Apologies were received from John Haine (TTP Comms), Simon Wilson (FEI), Graham McDonald (Nortel), David Palmer (Fujitsu), James Pago (Nokia), Arthur Christian (Hughes Network System), Roy Titchmarsh (Firstmark), Paul Grant (BT), David Mckone (Norweb Telecom), Spencer Pryor (AOL), Steve Czudej (Eircom), David Crawford, John Levett (Crown Castle), John McPherson (Ericsson), Peter Scrope (Tele2).

I. Agenda

Mr Lewis made a few minor changes to the order of the agenda. Documents referred to are tabled below.

II Minutes of the last meeting - BFWAtg(00)29

1. Minutes of the last meeting were agreed.

2. Matters arising

2.2. 3G Approach to Guard Bands for mobile operators
Mr Lewis said that the 3G Auction Team were having difficulty in locating the document, but he would follow it up with them.

2.3 Guard Band Issues BFWAtg(00)23

Mr Lewis developed inputs to the BFWA Consultative group on this issue and the action is now closed. However, members still need to look at the process for operator co-ordination and list an appropriate set of characteristics, parameters for co-ordination for the next meeting. He said that the BFWA Team examining the issue of adding something appropriate to the licensing process to identify the need for operators to co-ordinate with each other.

2.4 CEPT PT SE19 Update 26/28 GHz Interim Meeting BFWAtg(00)25
Mr Lewis thanked the two members who provided contributions to the interim SE19 meeting and said that their inputs had helped generate good discussion at the meeting resulting in document BFWAtg(00)33.

2.5 40GHz Issues BFWAtg(00)14 rev1
Mr Lewis has not received any input from members on the size of frequency slots. Therefore the action was still ongoing.

2.6 Adjacent Region Co-channel Co-ordination Tool Compliance Statement BFWAtg(00)26
Members were to look at Mr Nixon's document and provide feedback. Suggestions made at the last meeting have been incorporated, and the information has been progressed in RA. This action point is now closed.

III
3. Adjacent Region Co-ordination BFWAtg(00)32

3.1 Mr Lewis introduced the paper explaining that the objective was to examine the possibility of a co-ordination trigger value for adjacent area co-ordination based upon a Power Flux Density (PFD) level and an associated co-ordination distance dependant on transmitter EIRP. Having accepted this method the paper then proposes a co-ordination process flow diagram. This would help the development as of a co-ordination tool to address this issue. The group looked at and discussed a number of issues arising from the above paper. Mr Lewis explained that some numbers are in square brackets as we are awaiting the outcome of further work identified at a previous BFWAtg meeting. There were a number of issues raised:

	A percentage of time required against the acceptable level of interference. A closer examination of Rec452 is required. Action members and RA.
	Could the interference level be measured? - It was clarified that the process was not expected to involve any measurement being a calculation process.
	Being a single entry calculation, measurement would be difficult in a multiple interferer situation.
	Boundaries in valleys would be difficult - suggested re-wording accepted to specify the PFD "at or beyond the boundary".
	Attention was drawn to the conclusion from the study that suggests that operation within 5km of the boundary should be avoided for high density deployments.

Mr Lewis reminded the meeting that the figures proposed represented triggers for co-ordination to establish a need for co-ordination in certain deployment situations.

3.2 The flow charts on the co-ordination process show 2 possibilities if the trigger level is exceeded: The first is to take action to reduce the EIRP in direction of boundary, and the second is to enter into negotiation with neighbouring operator(s), with the possibility of moving the evaluation boundary for PFD threshold. Some members suggested operators should try to negotiate with each other first as the preferred initial route, saving lengthy calculations on co-ordination. The flow chart will be updated to reflect this. Some members, recognising the need for good inter operator co-operation, felt that some motivation was needed to get operators to co-ordinate with each other and it writing it into the Use It Or Lose It clause was suggested.

Action: Mr Lewis welcomed members' views on the proposed document. RA to update flow chart to reflect discussion.

3.3 Albera Report BFWAtg(00)36, 35
A BFWAtg Member submitted 2 useful examples of draft inter-operator agreements. He said that the idea was for operators to allow some interference in their neighbour's region, and to negotiate a relaxation of the PFD boundaries.

IV
4. Coexistence Issues
4.1 Coexistence Simulations for P-MP and MP-MP Networks BFWAtg(00)30, 31
A BFWAtg Member gave a presentation on the above which will be available on the website. He explained Mesh systems and the main conclusions of the coexistence study was that Mesh and PMP can easily co-exist, Guard bands can be reduced or even zero. CO-channel systems can be very close together, and rain fading has negligible impact on the results. The worst case involves interference to victim hub (central) stations.

4.2 A BFWAtg Member then demonstrated the simulation tool that was used to derive the results illustrated in document 31.
Action: Mr Lewis asked members for further input, especially any effect that the PFD boundary proposals have on these simulation results

V
5. CEPT SE19 Update
5.1 26/28GHZ Interim Meeting BFWAtg(00)33
The group looked at the executive summary extract from the preliminary report, considering inputs regarding methodology for determining if coexistence was feasible. The interim SE19 meeting had discussed the degree of coexistence between FWA and the ISOP counter proposal known as the "Interfered Area" (IA) approach. A BFWAtg Member added that common conclusions could be drawn from both advances. The difference in the methods is that the ISOP approach is based on the probability that an operator could place in an area suffering excessive interference whereas the Interfered Area approach identifies where the interference is in the cell. A BFWAtg Member said that another BFWAtg Member is undertaking some work on the figures and table, and to note that the figures are not yet agreed.

5.2 PP links in Band BFWAtg(00)34
Mr Nixon presented his document to the group on Point to Point links in band looking at the worst case geometry in order to understand whether PP links could operate within the overall co-ordination guidelines. A BFWAtg Member disagreed with the suggestion that the short link lengths suggested would not be useful. A BFWAtg Member asked if there were any calculations for equipment using ATPC. Mr Nixon said there wasn't.
Action: Mr Lewis and Mr Nixon to look at further issues of infrastructure, including the impact of ATPC, and further examination of useful link lengths v. availability

VI
6. Any Other Business
Mr Lewis reminded the group of the UK ETSI TM4 preparatory meeting on 5 June and asked them to think about their submissions to the TM4 meeting commencing on 19th June.

Date of Next Meeting
The date of the next meeting is 16 June 2000

Annex A

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