IEEE P802.11aa TG - MEETING UPDATE

Status of Project IEEE 802.11aa Task Group

Robust streaming of Audio Video Transport Streams

May 2009, Montreal, Quebec, Canada

Listened to the following proposals:

  1. Considerations for OBSS Sharing Using QLoad element (09/497r2)
  2. Considerations for Statistical Multiplexing Support for OBSS (09/496r2)
  3. OBSS Simulations/Results
    • OBSS Simulations (09/474r0),
    • Source for Video tests (09/524r0) and
    • OBSS 11g results (09/483r1)
  4. More Reliable Multicast/Broadcast results 09/528r1

Accomplishments

Vice-Chair -- Elected Alex Ashley as Vice-Chair for the Task Group

Listened to proposals/simulation results
Others
Internal review of Draft 0.01
Timeline review
Plan for the joint meeting with 802.1AVB (in the July plenary)

Plans

Teleconferences

July ‘09 meeting (San Francisco, California, USA)

Closing Report is in document 09/0613r0.

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March 2009, Vancouver, Canada

Listened to the following proposals (* at the joint meeting with 802.1AVB):

  1. Distributed Channel Assignment 09/285r0 Andrew Myles

  2. OBSS Analysis of Channel Requirements 08/1470r4 Graham Smith

  3. Overlapping BSS Proposal 09/230r0 Graham Smith

  4. OBSS OSQAP QoS Issues 09/347r0 Graham Smith

  5. Efficient Error Control Using Network Coding for Multicast Transmission 09/277r0 Kevin Rhee

  6. Feedback-jamming Multicast ARQ  09/.290r0 Jochen Miroll

  7. Quasi-reliable Multicast 09/247r0 Jochen Miroll

  8. More Reliable GroupCast Proposal Present 09/340r0 Hang Liu

  9. Drop Precedence in wireless, wired-wireless networks* 09/264r0 Alex Ashley

  10. AVB DMN and 802.11 09/0403r0* Philippe Klein

  11. Group addressed normative text 08/1244r2

Accomplishments

OBSS
Reliable Multicast
Joint Meeting with 802.1AVB

Plans

Teleconferences

May ‘09 meeting (Montreal, Quebec, Canada)

Closing Report is in document 09/0384r0.

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January 2009, Los Angeles, California

Listened to the following proposals:

  1. 08/0764-01 Using Packet Drop Precedence for Graceful Degradation  
  2. 09/0045-00 OBSS Simplification 
  3. 09/0022-00 Implementation for Intra AC differentiated Services
  4. 08/1244-00 Multicast Normative text discussion
  5. 09/0130-02 Efficient Error Control using BlockAck and Network Coding for Multicast
  6. 09/0124r0 EDCA and BlockAck extensions for Reliable Multicast/Broadcast Services

Agreed on a constrained definition of OBSS, for which TGaa will specify a solution. The definition is:

OBSS Definitions:

  1. OBSS edge: Any two APs operating in the same channel and can hear each other (either directly or via a STA associated to one of the APs)

  2. OBSS Graph: A graph where APs are nodes of the graph and the edges are OBSS edges and every AP within the OBSS graph can be connected via one or more OBSS APs to every other AP in the OBSS graph

  3. Length(OBSS graph): Longest shortest path between any two APs in the OBSS graph

  4. Size(OBSS graph): Number of nodes (APs) in the OBSS graph

 Scope of the 802.11aa OBSS Solution:

 if length(OBSS graph)  <= 2 and the size(OBSS graph) <=3 , enable the OBSS QAP solution otherwise (a) backoff  to legacy (non .11aa) mode or (b) use a different solution

Plans for the March 2009 meeting (Vancouver, BC, Canada)

  1. Adopt reliable multicast proposals into the draft
  2. Review and converge on OBSS definition/solution
  3. Based on input from 802.1AVB incorporate changes and adopt Intra-AC, Intra-Stream prioritization proposal(s) into TGaa draft 0.01
  4. Complete Draft 0.01

    Closing Report is in document 09/0172r0.

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November 2008, Dallas, Texas

Listened to updates on 4 technical proposals

Listened to a presentation from 802.21 SG "Handover to Broadcast Technologies"

Met jointly with 802.1AVB

input to 802.1Qat Designated MSRP Node specification describing interworking with 802.11

Goals for the January 2009 802.11 Interim Meeting in Los Angeles, CA:

Listen to technical proposals
Review/Approve Normative submissions corresponding to technical proposals
Start Draft 0.01 of TGaa amendment

September 2008, Waikoloa, Hawaii

Goals for the November 2008 802.11 Plenary Meeting in Dallas, TX is:

July 2008, Denver, Colorado

Goal for the September 2008 802.11 Interim Meeting at Waikoloa, Hawaii is:

May 2008, Jacksonville, Florida (first meeting as 802.11aa TG)

Goal for the July 2008 802.11 Plenary Meeting at Denver, Colorado is:

Status of Project IEEE 802.11 VTS Study Group (VTS SG is now 802.11aa TG)

Robust streaming of Audio Video Transport Streams

March 2008, Orlando, Florida

  1. Discussed 802.lQav/802.1Qat requirements in order to recommend appropriate 802.11 TSpec and TCLAS parameters

  1. Discussed “802.11 Network Bridge” problem and potential use of .11s 6-address frames as a solution

Goal for the May 2008 802.11 Interim meeting at Jacksonville, Florida is:

Jan 2008, Taipei, Taiwan

There are still some concerns on the VTS SG PAR/5C submission (includes two spelling errors). The issues will be discussed and addressed in the teleconferences.

Goal for the March 2008 802.11 Interim meeting is:

Nov 2007, Atlanta, Georgia

Tuesday Nov-13-2007 PM2:

    The intent of the second presentation was to add to the VTS SG scope the item "Link Adaptation Mechanisms".

Wednesday Nov-14-2007 PM2 (Joint meeting with 802.1):

Two straw polls were conducted following the above presentation to understand member interest in the techniques proposed in the above presentation --

  1. An approach to partition a packet into ‘sensitive’ and ‘not sensitive’ parts, ascertain that the ‘sensitive’ part arrived at the received intact and if it did, allow the ‘not sensitive’ part to be propagated to upper layers without verifying if it did arrive intact.

  2. An approach to add an additional encoding at the Transmitter and a corresponding decoding layer in the receiver in order to benefit from inter-packet FEC.

The straw polls and the corresponding results are :

Straw Poll-1

 

Allowing the 802.11 MAC layer to pass bit errors in the “unprotected” part of the packet:

 Should remain in the VTS SG PAR?

Yes: 19, No:  34

 

Straw Poll-2

 

Should the VTS SG PAR include a MAC-level FEC?

Yes: 26, No: 19

Based on the straw polls, it is clear that member interest in the technique is low.

A joint review of the VTS SG PAR submission (section 5.2 scope) and the scope statement was modified to read as follows:

            5.2 Scope of Proposed Standard: This amendment defines enhancements to the 802.11 MAC for robust video streaming.  The MAC enhancements specified in this amendment are:

−    Interworking with relevant 802.1 mechanisms including, but not limited to, 802.1Qat, 802.1Qav and 802.1AS

−    Link Adaptation Mechanisms

−    Increased robustness in overlapping BSS environments, based upon enhancing existing 802.11 mechanisms without the requirement for a centralised management entity.

−    Modified EDCA timing and parameter selection for video transport

−    Asynchronous multicast streaming independent of power save modes employed by associated stations.

Straw poll on support for the above scope statement:

Do you think the scope statement in Slide#21 is  appropriate for VTS SG?

Yes: 57, No: 4

Goal for the Jan 2008 802.11 Interim meeting is:

Sep 2007, Waikoloa, Hawaii

Monday Sep-17-2007 PM2:

Wednesday Sep-19-2007 PM2:

At the closing plenary the WG Motion to approve document 07-1972r6 and (a) forward it to ExCom for approval and (b) forward it to 802.1avb for consideration was amended. The amended motion reads "move to forward the PAR and 5 Criteria document IEEE-802.11-07-1972r6 to 802.1avb for consideration".

A following straw poll was conducted to understand what the Working Group members prefer in terms of the contents of the VTS SG PAR. The choices were:

Option-A: the scope statement defines the  general problem space – video streaming over 802.11. The specifics of what is included and what is not is defined by the TG in a “principles” or “requirements” document  (3)

Option-B: the scope statement is detailed enough to describe the specific areas that will be the focus of VTS (13)

Option-C: the scope statement defines the general problem space but section 7.4 of the PAR document will include the specifics (8)

None of the above: (1)

The goal for the Nov 2007 802.11 Plenary meeting is:

July 2007, San Francisco, California

VTS Study Group Report
The VTS Study Group met at the following times -

Wednesday July-18-2007 PM1:

Wednesday July-18-2007 PM2 (jointly with 802.1AVB) :

The goal for the Sep 2007 802.11 Interim meeting is to continue to discussions related to the VTS SG PAR/5C document, complete it and forward the document for WG approval.

 

May 2007, Montreal, Quebec

VTS Study Group Report
The VTS Study Group met twice during the week - Tuesday May-15-2007 and Wednesday May-16-2007 at the Fairmont The Queen Elizabeth Hotel in Montreal, Quebec.
The goal for the July 2007 802 meeting is to continue to discussions related to the VTS SG PAR/5C document, complete it and forward the document for WG approval.

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