IEEE 802 Study Group on BWA:
Coexistence Task Group
Documents Submitted for Meetings of March 9-11

(1) From: Leland Langston, Coexistence Task Group Chair, 3 Mar 1999

Summary of Task Group Comments prior to Meeting

(2) From: Scott Marin, 2 Mar 1999

Recommended LMDS Band Plan for Systems in the United States

(3) From: Scott Marin, 6 Mar 1999

Interference Considerations at LMDS/LMCS License Boundaries

(4) From: Scott Marin, 6 Mar 1999

Preliminary Draft Revision of ITU-R Recommendation F. 1191, "Bandwidth and Unwanted Emissions of Digital Radio-Relay Systems"

(5) From: Keith Doucet, 2 Mar 1999

Proposed Spectrum Plan for Multimedia Wireless Systems (MWS) for the European Market

(6) From: Asif Rahman, 2 Mar 1999

LMDS Band Plan Proposal

(7) From: Keith Bromberg, 18 Feb 1999

Fellow members of the Coexistence Task Group,

I thought it might be useful to share some thoughts ahead of meeting as to what spectrum etiquette elements should be covered in the proposed standard. As background, we have the "Band Plan and Spectrum Etiquette" write-up which Terry Smith prepared following the August 98 meeting (find it on the N-WEST web site under August 1998 meeting).

Terry's notes indicate that the August group felt that certain spectrum use elements should be specified, and other elements should not be specified. A summary is below with item numbers to assist discussion. My own comments are indicated with (*).

To be specified:

1. RF Channel Plan - raster based on increments of 3.5 MHz (ETSI) or 5 MHz (FCC).

(*) The raster could be based on a finer division, say 2.5 MHz, if that is useful.

(*) The proposal to use 5 MHz (or 2.5) will allow fuller use of the spectrum.

2. RF Spectrum Mask - mask according to rules already established by ETSI or according to FCC.

(*) The FCC and ETSI masks appear to be very similar. Can someone capture the essential difference?

3. Automatic Transmitter Power Control (mechanism to raise transmit power in response to fading or interference).

(*) A minimum range requirement would be useful, however too large a range will impose unwanted cost on transmitter design.

(*) Would the range will be simply determined by the ratio (in dB) between farthest and closed CPE transmitter. For example, 15,0000 feet : 500 feet = 30 dB.

Not to be specified:

4. Coodination Procedures (operators must follow FCC guidelines within 20km of BTA border)

5. Service types (any band segment should be able to deploy any service type)

6. Equipment Operating Modes.

(*) I would think modulation type, complexity, RF duplex technique (TDD vs FDD) will be addressed by the PHY group.

7. Antenna Polarization (must be verticle or horizontal per FCC and ETSI)

(*) The RF channel plan could remain silent on this issue, allowing equipment suppliers to offer spectrally competitive products.

8. Antenna Patterns (*)

Issues noted but left open for future meetings:

9. Minimizing receiver front-end overload

(*) I think automatic transmitter power control addresses that issue for PP links. In PMP links, CPEs which are close to their hub may require a large AGC range, but I think that is more an issue for the PHY group.

10. Balancing antenna polarities.

(*) I'm not clear why this is different from Item 7 above.

11. Minimizing transmit power levels.

(*) I'm not clear why this is different from Item 3 above.

12. Sharing common tower or rooftop hub sites.

(*) Sharing between PP and PMP, or sharing between A-Block and B-Block should be addressed by Items 1 to 8 above, are other sharing modes envisioned?

13. Process for dispute arbitration.

(*) The FCC has a process for BTA boundary issues in Part 101, is that sufficient?

14. Possibility of channel plan which accomodates MMDS 6 MHz channels.

(*) The 6 MHz constraint conflicts with both the 5 and 3.5 MHz rasters. I dont see why a common raster with MMDS spectrum would advance LMDS operations.

In addition,

I still wonder about the advisability of submitting a PAR just for the Coexistence work, versus trying to make Coexistence a Task Group under the "Standard for BWA" PAR, and finding a way to release this part of the standard ahead of other parts. It does not seem to me that "coexistence" warrants a separate PAR, or working group status.

However, I did draft preliminary scope and purpose statements, to think about this ahead of meeting:

Scope of Proposed Project:

This standard specifies certain usage parameters for the frequency bands which are allocated to LMDS services by the United States Federal Communications Commission. RF channel plans, emission masks, and transmitter power control are defined which allow terrestrial based point-to-multipoint and point-to-point radio systems to share the assigned spectrum.

Purpose of Proposed Project:

To enable deployment of terrestrial based radio links which allow delivery of broadband services that are competitive with wireline and space-satellite alternatives. To specify spectrum use rules which promote cost effective multi-vendor and multi-operator use of the radio frequencies.


Keith Bromberg
Wavespan Corporation

Roger Marks (