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Resend From: Andrew Myles (amyles) Sent: Friday, 30 March 2007 10:15 AM To: Kenneth Stanwood; Shellhammer, Steve; stds-802-19@ieee.org; bji@sta.samsung.com; bkraemer@ieee.org; david.grandblaise@MOTOROLA.COM; dickroy@alum.mit.edu; Douglas Chan (dougchan); eldad.perahia@INTEL.COM; fm@octoscope.com; john.sydor@crc.ca; marianna.goldhammer@ALVARION.COM; Paul Piggin; wuxuyong@HUAWEI.COM Subject: RE: Conference Call - Coexistence in the 3650 MHz band G'day Ken
If the 802.16 gear does not exist then it could be a little
difficult to do a test. ;(
However, one could do a baseline test to validate your
simulation using regular 802.16 and regular 802.11 equipment. Do you have any
results for such tests? I have heard second hand that 802.16 does very
poorly when operating in the same channel as 802.11. Is this true or partially
true? What is the mechanism?
As I noted, I am not sure whether the exact form of the
simulation of 802.11 actually matters for your purposes. However, you should be
using EDCA and not DCF, and in DCF one does not need to wait DIFS for the first
packet of a stream when the medium has been free for a
while.
Andrew From: Kenneth Stanwood [mailto:KStanwood@cygnuscom.com] Sent: Friday, 30 March 2007 10:03 AM To: Andrew Myles (amyles); Shellhammer, Steve; stds-802-19@IEEE.ORG; bji@sta.samsung.com; bkraemer@IEEE.ORG; david.grandblaise@MOTOROLA.COM; dickroy@alum.mit.edu; Douglas Chan (dougchan); eldad.perahia@INTEL.COM; fm@octoscope.com; john.sydor@crc.ca; marianna.goldhammer@ALVARION.COM; Paul Piggin; wuxuyong@HUAWEI.COM Subject: RE: Conference Call - Coexistence in the 3650 MHz band Hi Andrew, Given that the tools for coexistence being
developed within 802.16 are just that – being developed, running tests of those
tools with real hardware is not only difficult but currently impossible.
Hence the simulations provide an alternative approach to help direct the
development of those tools for coexistence. Additionally, it would be helpful if you
could provide us with the correct use of DIFS. Such information is a
valuable outcome of the joint conference calls and greatly
appreciated. Thanks, Ken From: Andrew
Myles (amyles) [mailto:amyles@cisco.com] G'day
all I looked at this
presentation and noticed that the MAC model for 802.11 is simplistic (eg,
it uses DCF instead of EDCA) and wrong (eg, the use of DIFS is incorrect in
the flow diagram). These problems may or may not matter, depending on what we
are trying to achieve here. However, it started me thinking about why we are
doing this and how we are doing it. My view of simulation
is that it is "doomed to be successful", ie you usually get the conclusion you
want. What that conclusion is usually depends on the biases of the people doing
the simulation. This suggests one should avoid simulation if at all possible,
certainly as the basis of important decisions. So what are the
alternatives? Given the fact that 802.11 and 802.16 equipment exists, it should
not be too difficult to run some actual tests with real hardware. Although tests
like this also have some issues of design and interpretation, the results
would be far more interesting and realistic than any
simulations. Comments? Andrew
Myles From:
stds-802-19@IEEE.ORG [mailto:stds-802-19@IEEE.ORG] On Behalf Of Shellhammer, Steve All,
Here is the updated presentation from Paul.
Ian please post on the web site in the misc area. Steve From: Paul
Piggin [mailto:ppiggin@nextwave.com] Hi
Steve, This is my revised
presentation for later today. I have also uploaded to the LE TG area
at: http://dot16.org/CSUpload//upload/LE_db/S80216h%2d07_038r1.pdf Thanks, Paul. From:
Shellhammer, Steve [mailto:sshellha@qualcomm.com] This is a reminder that we have a
conference call on Coexistence in the 3650 MHz band, on Thursday at 11 AM
Eastern Time (8 AM Pacific Time). Paul Piggin will be
presenting. Here is a link to his original
presentation, http://ieee802.org/19/pub/2007/misc/S80216h-07_038.pdf Paul is working on an update that
will be available prior to the call. Here is the bridge
information, TO ATTEND THE
AUDIO CONFERENCE: 1. Call +1
858-845-5000 2. After the greeting press 1 to
attend meeting. 3. Enter Meeting ID 80219 4. Enter Meeting Password 80219 followed by the #
sign. 5. Follow the remaining prompts for
recording the callers name and joining the meeting. For assistance, dial #0 at any
time. Steve |