1. September 2008
doc.: IEEE /1003r0
March 2009
802.11aa – Robust Audio Video Transport Streaming Vancouver, British Columbia Closing Report
Date:
Authors:
Ganesh Venkatesan, Intel Corporation
Alex Ashley, NDS Ltd

2. September 2008
November 2007
doc.: IEEE /2752r1
doc.: IEEE /1003r0
March 2009
Abstract
This submission summarizes TGaa the activities of TGaa in the IEEE Vancouver Session (March 2009).
Slide 2
Ganesh Venkatesan, Intel Corporation
Page 2
Alex Ashley, NDS Ltd
Peter Ecclesine, Cisco Systems

3. Snapshot Since the Los Angeles session:
March 2009
Snapshot
Since the Los Angeles session:
2 Teleconferences focused on (a) OBSS and (b) Reliable Multicast.
Goals for the Vancouver Session:
OBSS
Adopt formal definition of OBSS for TGaa
Listen, review and adopt OBSS solution into the TGaa draft
Listen, review, down select and adopt Reliable Multicast mechanism(s) into TGaa draft
Jointly meet with 802.1AVB:
Discuss specific input to DMN specification
Discuss viability of the ‘drop precedence’ idea
Ganesh Venkatesan, Intel Corporation

4. What we did this week? OBSS Reliable Multicast
March 2009
What we did this week?
OBSS
Listened to four presentations on OBSS in the context of TGaa
Started discussions on a strategy and plan for OBSS
Reliable Multicast
Reviewed the harmonized set of Reliable Multicast mechanism(s)
Listened to 2 additional proposals on reliable multicast
Adopted harmonized Reliable Multicast mechanism(s) into TGaa draft
Joint Meeting with 802.1AVB
How to accommodate SRP in ?
Strategies for priority levels, precedence levels and drop precedence
Teleconference schedule
Ganesh Venkatesan, Intel Corporation

5. Plans for the Montreal (May 2009) Session
March 2009
Plans for the Montreal (May 2009) Session
In upcoming teleconferences
Layout a OBSS strategy and plan
MRG discussions
Additional mechanisms for Reliable Multicast
Address other topics from TGaa PAR
Plans for May ‘09 (Montreal) Meeting
Continue activities from teleconferences
Technical presentations on TGaa PAR topics
Review and improve TGaa draft
Slide 5
Ganesh Venkatesan, Intel Corporation

6. March 2009
Teleconferences
Bi-weekly on Mondays between Hrs ET, starting March 23rd 2009 till July 27th, 2009.
Schedule will be announced in the TGaa reflector soon.
Slide 6
Ganesh Venkatesan, Intel Corporation

7. March 2009
Background details
Ganesh Venkatesan, Intel Corporation

8. Technical Presentations
March 2009
Technical Presentations
Distributed Channel Assignment 09/285r0 Andrew Myles
OBSS Analysis of Channel Requirements 08/1470r4 Graham Smith
Overlapping BSS Proposal 09/230r0 Graham Smith
OBSS OSQAP QoS Issues 09/347r0 Graham Smith
Efficient Error Control Using Network Coding for Multicast Transmission 09/277r0 Kevin Rhee
Feedback-jamming Multicast ARQ 09/.290r0 Jochen Miroll
Quasi-reliable Multicast 09/247r0 Jochen Miroll
More Reliable GroupCast Proposal Present 09/340r0 Hang Liu
Drop Precedence in wireless, wired-wireless networks* 09/264r0 Alex Ashley
AVB DMN and /0403r0 Philippe Klein
Group addressed normative text 08/1244r2
* Discussed at the joint meeting with 802.1AVB
Slide 8
Ganesh Venkatesan, Intel Corporation

9. What is OBSS? OBSS Definitions:
September 2008
November 2007
doc.: IEEE /2752r1
doc.: IEEE /1003r0
What is OBSS?
March 2009
OBSS Definitions:
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)
OBSS Graph – is a graph where APs are nodes of the graph and the edges are OBSS edges and every AP with in the OBSS graph can be connected via one or more OBSS APs to every other AP in the OBSS graph
Length(OBSS graph) – longest shortest path between any two APs in the OBSS graph
Size(OBSS graph) – number of nodes (APs) in the OBSS graph
Scope of TGaa OBSS Solution (proposed in Los Angeles session) –
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
Slide 9
Ganesh Venkatesan, Intel Corporation
Page 9
Alex Ashley, NDS Ltd
Peter Ecclesine, Cisco Systems

10. Issues with the scope of OBSS solution?
September 2008
November 2007
doc.: IEEE /2752r1
doc.: IEEE /1003r0
March 2009
Issues with the scope of OBSS solution?
Length (OBSS graph) <= 2 is insufficient?
2.4GHz band has only 3 channels and suffers in OBSS environment. It is not in the scope of TGaa OBSS solution
If the number of channels is > 17, a length of greater than 2 is improbable
A length of 7 or 8 is common in dense deployments if the number of available channels is limited 9 or 11. This condition could be mitigated by having the QAPs fall back from 40MHz to 20MHz channels. Should TGaa specify a mechanism for this?
Is a mechanism/solution that only addresses the scope as defined acceptable (despite the fact that consistent performance will not be met) as an incremental step over legacy?
If a length of 7 or 8 is accepted to be the scope of the solution, it is not any simpler than the general OBSS problem (which is considered NP-Hard)
Slide 10
Ganesh Venkatesan, Intel Corporation
Page 10
Alex Ashley, NDS Ltd
Peter Ecclesine, Cisco Systems