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802.11aa – Robust Audio Video Transport Streaming Vancouver, British Columbia Closing Report. Date: 2009-03-12. Authors:. Abstract. This submission summarizes TGaa the activities of TGaa in the IEEE 802.11 Vancouver Session (March 2009). Slide 2. Recognition.
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802.11aa – Robust Audio Video Transport Streaming Vancouver, British Columbia Closing Report Date: 2009-03-12 Authors: Ganesh Venkatesan, Intel Corporation
Abstract This submission summarizes TGaa the activities of TGaa in the IEEE 802.11 Vancouver Session (March 2009). Slide 2 Ganesh Venkatesan, Intel Corporation
Recognition Alex Ashley – for volunteering to be TGaa secretary for the entire week. Ganesh Venkatesan, Intel Corporation
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 802.11 specific input to DMN specification • Discuss viability of the ‘drop precedence’ idea Ganesh Venkatesan, Intel Corporation
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 802.11? • Strategies for priority levels, precedence levels and drop precedence • Teleconference schedule • Minutes from the session are in document 09//371r0 Ganesh Venkatesan, Intel Corporation
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 6 Ganesh Venkatesan, Intel Corporation
Teleconferences Bi-weekly on Mondays between 1100-1230Hrs ET, starting March 23rd 2009 till July 27th, 2009. Schedule will be announced in the TGaa reflector soon. Slide 7 Ganesh Venkatesan, Intel Corporation
Background details Ganesh Venkatesan, Intel Corporation
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 802.11 09/0403r0 Philippe Klein Group addressed normative text 08/1244r2 * Discussed at the joint meeting with 802.1AVB Slide 9 Ganesh Venkatesan, Intel Corporation
What is OBSS? 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 10 Ganesh Venkatesan, Intel Corporation
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 11 Ganesh Venkatesan, Intel Corporation