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RE: stds-80220-requirements: Max Tolerable Delay Spread, 4.2.3




Neka

I agree with your rationale and max tolerable delay is an important
parameter quantifying our statement for support of the different
environments for an MBWA system.

I know the channel modeling experts group will come up with the channel
models complying with the requirement of support of the system in
different environments i.e. urban, suburban rural etc. Can anyone from
that group give insight as to what would be the max tolerable delay
spread for the scenarios in the requirements document? 

In our testing at Sprint, we have seen delay spreads in excess of 5
microseconds in some cases (although the percentage of those channels is
very small).

Thanks

Khurram P. Sheikh
Chief Technology Advisor
Sprint- Broadband Wireless
Tel (SM): 650-513-2056
Tel(KC): 913-762-1645
Mobile: 650-906-8989
khurram.p.sheikh@mail.sprint.com


-----Original Message-----
From: Neka Hicks [mailto:nhicks@Clearwire.com] 
Sent: Wednesday, July 30, 2003 9:11 AM
To: 'Joanne Wilson'
Cc: Stds-80220-Requirements (E-mail)
Subject: RE: stds-80220-requirements: Max Tolerable Delay Spread, 4.2.3


Joanne,

Several contributions from participants in the channel modeling group
have
included proposed channel models for different environments including
rural,
suburban, and urban/dense-urban.  Urban/dense-urban channel models
reflect
the highest delay spread, and 5 micro-seconds is typically accepted as a
suitable value for this type of environment.  If the system is going to
work
under these conditions, then it must be able to tolerate a delay spread
of
atleast 5 micro-seconds.

-----Original Message-----
From: Joanne Wilson [mailto:joanne@arraycomm.com]
Sent: Tuesday, July 29, 2003 5:24 PM
To: Neka Hicks; Stds-80220-Requirements (E-mail)
Subject: RE: stds-80220-requirements: Max Tolerable Delay Spread, 4.2.3


Neka,

You have provided a rationale for your proposal,

         "The maximum tolerable delay spread should be specified so that
it
can be
          determined whether various vendor proposals can meet this
criteria."

which I don't believe to be a valid reason for establishing such a
requirement.
Can you provide any other reasoning for this proposal?  I would expect
the
rationale to explain why such a requirement would be essential for the
802.20 MBWA
to achieve it performance objectives.

Best regards,

Joanne Wilson
ArrayComm, Inc.
joanne@arraycomm.com



-----Original Message-----
From: owner-stds-80220-requirements@majordomo.ieee.org
[mailto:owner-stds-80220-requirements@majordomo.ieee.org]On Behalf Of
Neka Hicks
Sent: Tuesday, July 29, 2003 3:19 PM
To: Stds-80220-Requirements (E-mail)
Subject: stds-80220-requirements: Max Tolerable Delay Spread, 4.2.3


All,

Here's a contribution regarding max tolerable delay spread:

 <<clearwire contribution 072803 - max tolerable delay spread.doc>>

Neka C. Hicks
Director of Network Engineering
Clearwire Technologies

469-737-7555 (office)
817-706-2548 (cell)