November 2006
doc.: IEEE 802.19-06/0045r0
IEEE P802.19
Wireless Coexistence
November 2006 Minutes
Date: 2006-11-15
Author(s):
Name
Stephen R Whitesell
Company
VTech
Communications
Address
2 Shannon Ct
Howell, NJ 07731
Phone
732 751 1079
Email
swhitesell@vtech.ca
Abstract
This document provides a record of the minutes for the November 2006 meeting of the IEEE 802.19
Coexistence Technical Advisory Group.
Notice: This document has been prepared to assist IEEE 802.19. It is offered as a basis for discussion and is not binding on the
contributing individual(s) or organization(s). The material in this document is subject to change in form and content after
further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.
Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution,
and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE
Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit
others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and
accepts that this contribution may be made public by IEEE 802.19.
Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures <http://
ieee802.org/guides/bylaws/sb-bylaws.pdf>, including the statement "IEEE standards may include the known use of patent(s),
including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents
essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the TAG of patent
information that might be relevant to the standard is essential to reduce the possibility for delays in the development process
and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair
<Shellhammer@ieee.org> as early as possible, in written or electronic form, if patented technology (or technology under patent
application) might be incorporated into a draft standard being developed within the IEEE 802.19 TAG. If you have questions,
contact the IEEE Patent Committee Administrator at <patcom@ieee.org>.
Submission
page 1
Steve Whitesell, VTech
November 2006
doc.: IEEE 802.19-06/0045r0
The IEEE 802.19 Coexistence Technical Advisory Group (TAG) met in conjunction with the IEEE 802
Plenary Session in Dallas, TX during the week of November 13-17, 2006. Minutes for each of the
meetings held during the week are provided below.
Tuesday PM1
Chair Steve Shellhammer called the meeting to order at 1:40 pm. He reviewed the objectives and the
meeting times for the week in 06/0038r3. He then reviewed the agenda. There was no objection to
accepting the agenda as presented. He then went over the IPR statement and the subjects not to discuss
during the meeting as found in 06/0017r0.
Secretary Steve Whitesell reviewed the minutes from the July meeting since they had not been available
for approval in September. He noted there was an error in referring to the 802.11n CA document
presented by Eldad Perahia as 11-06/0338r4. It was actually the r3 version with some proposed changes.
The minutes will be revised to reflect this. With that change, there was no objection to accepting the July
minutes as modified in 06/0032r1.
Since Steve W was not able to attend the September meeting in Melbourne, Joseph Levy served as
interim secretary and recorded the minutes in 06/0037r0. Steve W reviewed the document, noting that
only one two-hour session was held. There was no objection to accepting the document as presented
Eldad P presented the updated 11-06/0338r4 CA document for 802.11n that had been approved at the
September meeting. He also introduced 11-06/1482r0, which summarizes the main issues that were to be
addressed in the 11n CA document. One important change is treating Bluetooth® (BT) as an interferer by
using a proper PSD mask and frequency hopping rather than treating it as broadband noise. When this
was done, the 11n receiver was found to be more sensitive to Bluetooth than to a broadband noise signal.
This happens because Bluetooth wipes out 2 or 3 of the tones and results in a degraded signal-tointerference (SIR) ratio. He had to redo link budgets as a consequence. He then repeated this new
analysis for the 40 MHz 11n scenario with similar results.
Another update to the CA document was to look at partial packet failures in the 802.11n due to BT
interference. With A-MSDU aggregation the results are the same because the entire aggregate is
protected by a single FCS. With A-MPDU aggregation each MPDU has its own FCS and performance is
substantially improved when there is high Bluetooth occupancy. For average occupancy cases, the
improvement is more modest. He also added probability of collision plots for both the 20 MHz and 40
MHz cases.
Eldad also looked at 802.15.4 pertinent parameters and showed interference results for the cases where
there is channel overlap. However, he noted that because of the very low duty cycle of 802.15.4, there is
a very low probability of collision. Thus, he did not do a temporal analysis; instead he just showed the
results for the few times when interference does occur.
Eldad then quickly reviewed where the changes summarized in 11-06/1482r0 were actually incorporated
into 11-06/0338r4. He noted that the document may have to be revised to fix a typo in the header. The
former text that had been used to model the interferer as wideband noise has been moved from Bluetooth
section to 802.16 section of the CA document. He has also redone FHSS WDCT cordless telephone
analysis using same procedure as for Bluetooth.
Mark Austin then presented document 06/0041r0 introducing the European Radiocommunications Office
(ERO) Monte Carlo radio modeling tool SEAMCAT (Spectrum Engineering Advanced Monte Carlo
Analaysis Tool). It is a freely available software program that we may want to consider including in the
Recommended Practice document being developed by the TAG. It can be used for a variety of purposes
including:
Submission
page 2
Steve Whitesell, VTech
November 2006
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doc.: IEEE 802.19-06/0045r0
Quantification of interference levels
Consideration of spatial and temporal distributions of received signals
Sharing and compatibility studies
Evaluation of transmitter and receiver masks
Evaluation of limits for certain radio parameters
The current software release is SEAMCAT-3. It includes support for the open Java platform,
implementation of plugin modularity, and algorithms for direcdt simulation of CDMA systems. The goal
for next release is to include OFDM modulation and to make it open source code. Mark opened a copy of
the program and gave an overview of how parameters are entered and results are presented.
The TAG expressed interested in learning more about SEAMCAT at the London meeting in January.
Steve S indicated he would be willing to allocate a complete two-hour time slot for this purpose. There
was discussion about asking the SEAMCAT presenters if they can run a couple of the scenarios we have
already analyzed for comparison purposes. It was suggested that BT interference with 802.11n would be
a good example. We will also want to question them about the amount of work that would be required to
create plug-ins or models applicable to 802 radios.
The meeting was recessed at 3:22 pm.
Tuesday PM2
Chair Steve S called the meeting back to order at 4:05 pm. He indicated he had three contributions for the
Recommended Practice document. The first is 06/0043r0, which provides an outline for the document.
There was much discussion about how we should identify and distinguish the various coexistence
scenarios. A proposal was made to separate metrics from evaluation methods and not tie them to specific
scenarios. The changes made to the outline are captured in 06/0043r1.
Steve S then presented a very simple coexistence scenario in document 06/0042r0. It describes a pair of
unlicensed networks operating in a common physical area and in the same frequency band. The TAG
decided it is not important to distinguish licensed from unlicensed use. Pafter further discussion, it was
agreed the parameters to be specified in such a scenario include the number of networks involved (we will
stick with 2 for now), the number of stations or nodes in the network, the proximity of operating
frequencies, whether the networks are frequency static or hopping, and any adaptation to spectral activity.
The meeting was recessed for the day at 5:55 pm.
Wednesday PM 1
Chair Steve S reconvened the meeting at 1:41 pm. He briefly reviewed the TAG’s work in revising the
outline for the document given in 06/0043r1 during the Tuesday PM2 for those who had not been in
attendance. He the presented document 06/0036r2 describing a scenario for Dynamic Frequency
Selection (DFS). It has three sub-cases: single collocated transmitter and receiver (radar system), single
transmitter with multiple receivers (reuse of TV bands), and multiple collocated transmitters and receivers
(802.11 and DFS enabled ZigBee).
Steve S suggested we work on revising wording of the document to remove regulatory terminology and
make it as general as possible. Steve W pointed out that some of the terminology we were discussing
yesterday differs from that in the document (e.g., proximity of operating frequencies vs. channels) and
that, if we adopt that terminology, it may affecting wording of this scenario. However, the TAG went
ahead with work toward revising the wording with knowledge that further changes might have to be
made.
The meeting took an early recess at 3:06 pm.
Submission
page 3
Steve Whitesell, VTech
November 2006
doc.: IEEE 802.19-06/0045r0
Wednesday PM 2
Chair Steve S reconvened the meeting at 3:45 pm. The group resumed discussion and editing of
06/0036r2. We decided to create two scenarios, one for the case where a DFS system starts up in a
frequency band where another non-DFS system is operating, and one for the case where a DFS system
must continue to monitor the spectrum for the appearance of a new non-DFS system. The TAG also
decided to do separate scenarios for each of the three sub-cases that had been discussed and to add a
fourth for the sub-case of remote microphones communicating to a central receiver operating in the TV
bands.
Joe Levy suggested creating a matrix and try to group similar scenarios. The TAG spent a little time
working on this, but was not able to complete the task. Joe L and David C will create tables of possible
scenarios (Joe for the DFS scenarios and David for the simple networks as discussed yesterday) off line.
The group did not feel further work on writing words for the scenarios in 06/0036r2 would be fruitful
until this was done, but the results of edits made so far are captured in 06/0036r3.
Steve S then introduced 06/0040r0 describing some proposed metrics and evaluation methods for the DFS
scenarios. It includes definitions for concepts such as “keep-out region”. The evaluation method includes
a 10-step process for calculating average probability of misdetection at the edge of the keep-out region
and should apply to a number of different scenarios and interfering source types. A different evaluation
method may be needed for the network on network scenario.
The meeting was adjourned for the week at 5:17 pm.
Attendance
Name
Mark Austin
David Cypher
Joseph Levy
Sheung Li
Dominic Paulrat
Eldad Perahia
Steve Shellhammer
Steve Whitesell
Submission
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Steve Whitesell, VTech
November 2006
doc.: IEEE 802.19-06/0045r0
References:
11-06/0338r4 – p802.11n Coexistence Assurance Document, Perahia & Li
11-06/1482r0 – CA Document Update, Perahia
19-06/0017r0 – IEEE IPR Policy, Shellhammer
19-06/0032r1 – July 2006 Minutes, Whitesell
19-06/0036r3 – Coexistence Scenario for Dynamic Frequency Selection (DFS), Shellhammer
19-06/0037r0 – September 2006 Minutes, Levy
19-06/0038r3 – November 2006 Agenda, Shellhammer
19-06/0040r0 – Metrics and Evaluation Methods for DFS Scenarios, Shellhammer
19-06/0041r0 – SEAMCAT Introduction, Austin
19-06/0042r0 – Coexistence Scenario for a Pair of Unlicensed Wireless Networks, Shellhammer
19-06/0043r1 – Outline of the Recommended Practice, Shellhammer
Submission
page 5
Steve Whitesell, VTech