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Re: [802SEC] +++10 Day EC Email Ballot (Closes no later than 29 April 2007)+++ Motion to approve the formation of the 802.11 Video Transport Stream (VTS) Study Group




-----Original Message-----
From: ***** IEEE 802 Executive Committee List *****
[] On Behalf Of Stuart J. Kerry
Sent: Wednesday, April 18, 2007 13:10
Subject: [802SEC] +++10 Day EC Email Ballot (Closes no later than 29
April 2007)+++ Motion to approve the formation of the 802.11 Video
Transport Stream (VTS) Study Group


Dear EC Members, 


The 802 EC Chair has delegated me to conduct this EC ballot on his

This is a 10 day email ballot to make a determination on the withdrawn
motion which was deferred to an 802 EC email ballot, that was submitted
to the Closing Orlando March 2007 802 EC meeting: 


Motion:  "To approve formation of an IEEE 802.11 Study Group to examine
issues related to delivery of Video Transport Streams (VTS) over IEEE
P802.11, with the intent to create a PAR and Five criteria to form a new
Task Group. The proposed PAR and 5C would be reviewed by the 802.1 Audio
Video Bridging Task Group (802.1AVB TG), and in addition both the
802.1AVB TG and 802.11 VTS SG (and eventually the 802.11 TG, if formed)
will meet jointly at IEEE 802 plenary meetings, unless mutually agreed
not to".

Moved: Stuart J. Kerry 

Seconded: Tony Jeffree

This ballot opens 11:59 PM ET Wednesday 18th, 2007 and closes when all
voting EC members have cast a ballot but no later than 11:59 PM ET
Sunday April 29th, 2007 if enough ballots have been cast for a decision
to be made (more than 9 approves or disapproves).  


Executive Summary:


The proposed 802.11 Video Transport Stream (VTS) Study Group will focus
on enhancements within the 802.11 MAC/PHY layers to improve video
streaming performance over 802.11 links. The problem space is
constrained to be limited to issues unique to 802.11 and nothing more.


The 802.11 VTS SG will collaborate with 802.1AVB TG to ascertain that
802.11 specifications include support for all mechanisms specified in
802.1AVB. If there are no mechanisms within 802.11 to support 802.1AVB,
the 802.11 VTS SG will work jointly with 802.1AVB TG to specify the
required mechanisms. This strategy is decided based on discussions with
Michael Johas Teener (802.1AVB TG Chair) and Ganesh Venkatesan (Proposed
Chair of the 802.11 VTS SG, if approved), as well as the two WG Chairs.


If the 802.11 VTS SG formation is approved by the EC, the tentative
schedule for 802.11 VTS SG in May interim meeting in Montreal includes a
presentation on 802.1AVB and 802.1AVB Transport Protocol followed by a
discussion how
802.11 fits into this specification. These meetings are open to all 802

Approved in 802.11 WG:

.         802.11 WNG SC - Results: 59-3-11

.         WG - Results: 76-1-25





802.11 VTS SG is focused on enhancements within the 802.11 MAC/PHY
layers to improve the performance of video streams sent over 802.11
links. This is the main focus of the 802.11 VTS SG and is expected that
the SG will spend 80% of its time in this activity. Some of the areas
for study are (not in any specific order, not a complete list). Some of
these topics are not fully explored yet:


1.     Enhancements to 802.11e mechanisms to render them effective for
transport streams (not all bits are equal

2.     QoS Management mechanisms  (permits QoS control from higher

3.     Optimizations to make medium access more deterministic

4.     Forward Error Correction techniques that are effective for 802.11
(specifically low reliability of the medium)

5.     Resiliency mechanisms to mitigate interference

6.     Heuristics for retransmission, packet drop, etc

7.     Channel dynamics estimation and adaptation techniques 

In addition (if there are currently no known mechanisms in 802.11) the
VTS SG, in order to guarantee that the wired and wireless sub-systems
can co-exist, will also work on the following items listed below. It is
anticipated that the items in this list will involve some level of joint
activity between 802.1AVB TG and 802.11 VTS SG. About 20% of the 802.11
VTS SG activity is expected here. Please note that the items listed
below will be in 802.11 (if needed) but will be performed jointly with
the experts from 802.1AVB TG.


.         Mechanisms to support those specified by 802.1 Qat (stream
reservation protocol - bandwidth, latency, Admission Control and Time
Synchronization) and 802.1Qav (forwarding and queuing of time-sensitive
streams). Note that support for 802.1AS is already included in 802.11v.

.         Mechanisms to support 802.1Qas (time synchronization).

.         Any additional mechanisms that are specified in 802.1AVB
additional support in 802.11. 

A liaison will be established between 802.1AVB TG and 802.11 VTS SG. The
liaison will ascertain 802.1 AVB mechanisms and optimizations in 802.11
for video streaming are compatible and they work together to improve
streaming performance. This will be a 2-way communication - advancements
in 802.1AVB will be made known to the 802.11 VTS SG members and
advancements made in the SG made known to 802.1AVB TG members.


.         The documents generated by the two groups may be reviewed by
other (on a case by case basis), 

.         There may be presentations from one group to the other to
rationale/motivation for an approach/solution and 

.         Members from each group will attend meetings of the other when



/ Stuart 


Stuart J. Kerry
Chair, IEEE 802.11 WLANs WG 

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