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Mesh Media Access Coordination Ad Hoc Group Report Out

Mesh Media Access Coordination Ad Hoc Group Report Out. L. Lily Yang (Intel Corp.) lily.l.yang@intel.com. Ad Hoc Group Activities since Portland meeting. One face to face meeting at Portland, 07-25-04 Decided to first focus on a list of issues in MAC Set up a WiKi page for the group:

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Mesh Media Access Coordination Ad Hoc Group Report Out

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  1. Mesh Media Access Coordination Ad Hoc Group Report Out L. Lily Yang (Intel Corp.) lily.l.yang@intel.com Lily Yang

  2. Ad Hoc Group Activities since Portland meeting • One face to face meeting at Portland, 07-25-04 • Decided to first focus on a list of issues in MAC • Set up a WiKi page for the group: • http://ieee.comnets.rwth-aachen.de/cgi-bin/wiki.pl?MeshMediaAccessCoordinationGroup • One teleconference call, 08-19-2004 • Clarified the scope of the ad hoc group: Mesh Media Access Coordination Function • Changed the group name • Worked on the issue list • More discussion over emails on the issue list • Outcome of the group: #968r05 Lily Yang

  3. Mesh Point Reference Architecture Internetworking Configuration/ Management Interfaces IEEE802.11s Amendment .11s Mesh Network Measurement Layer 2 Mesh Routing and Forwarding .11s Mesh Security Mesh Media Access Coordination Function IEEE802.11 MAC IEEE802.11 a/b/g/j/n IEEE802.11PHY *[1] slide#3 Lily Yang

  4. Purpose of #968 (Issue List) • Informational: provide suggestions on what are the technical challenges the 11s proposal might want to address for Mesh Media Coordination Function • NOT a requirement document • FLAT list of issues: • No significance to the order • No prioritization done to the list yet • Up to TGs to decide • What is the minimum requirements • What is out of scope • What is optional Lily Yang

  5. Two Operational Phases • Mesh Discovery and Mesh Link Establishment (Section 3 in #968) • Mesh Discovery: mesh beacon? • Link Establishment: • Mesh authentication? • Mesh association? • Normal Operational Phase (Section 4 in #968) • Mesh Media Access Coordination Function is in action Lily Yang

  6. List of Issues in Mesh Media Access Coordination Function • 11 Issues documented in 968 • Most are needed due to the “mesh” nature • Missing or inadequate in current 11/11e MAC • Opportunities presented by mesh Lily Yang

  7. Issue #4.1 Hidden Terminal Problem hidden nodes: nodes in I(R) but not S(T) T R H S(T): Sensing range of T I(R): Interference range of R Lily Yang

  8. STA1 STA2 STA3 STA4 STA1 STA2 STA3 STA4 Issue #4.1 Performance Impact Case (c) Case (a) Case (b) Case (d) Case (b) Case (a) Case (c) Case (d) Lily Yang

  9. Issue #4.2 Exposed Terminal Problem E T R hidden nodes: nodes in S(T) but not in I(R) S(T): Sensing range of T I(R): Interference range of R Lily Yang

  10. Issue #3 Flow Control from source to destination • 11 DCF: packet-based fairness • 11e EDCA (TXOP): time-based fairness • Fixed slow client problem for BSS • Improve BSS network throughput • But may introduce problem for multi-hop path with multi-rate 11 mb/s 2 mb/s Lily Yang

  11. Issue #4.3 Another Flow Control Example Individual flow throughput (b/s) N4 N0 N1 N2 N3 Flow 1 Flow 2 Load (mb/s) Lily Yang

  12. Lack of Flow Control: Example (cont.) Actual Scheduling Result when load=700kb/s e2e throughput 674k 449k 355k 235k Congestednodes 238k 347k 697k 450k Rx: 238k 1020k 899k 1056k 235k Tx: 674k 687k 702k 685k 697k Wasted TX Ideal Scheduling, when the network is overloaded 430k 430k 430k 430k 430k 430k 430k 430k e2e throughput Rx: 430k 860k860k 860k 860k Tx: 430k 860k 860k 860k 430k Lily Yang

  13. Issue #4.4 Mesh Load Balance Lily Yang

  14. Issue #4.5 Multi-hop Scheduling Lily Yang

  15. Issue #4.6 Distributed Admission Control 11s Admission Control 11e Admission Control Mesh AP STA Lily Yang

  16. Issue #4.7 Distributed QoS Management Mesh AP STA Lily Yang

  17. Issue #4.8 Mixture of BSS Traffic and Forwarding Traffic Relaytraffic Mesh AP • When Mesh Point co-located with AP on one RF interface: • How to coordinate the relay traffic for mesh point and the BSS traffic for AP? STA N4 N0 N1 N2 N3 BSS traffic Lily Yang

  18. Issue #4.9 Scalability • Different usage models: • Small home • Medium size office • Large campus and community network • Variable: • Network size • Node density • Fixed EDCA parameters? Lily Yang

  19. Issue #10 Channelization A A->B: channel n C->D: channel m D C B Lily Yang

  20. Issue #11 Multiple Radios Mesh AP Mesh Point Forwarding Traffic from/to Other Mesh Points Using multi-radio to implement channelization BSS traffic To/from Stations Lily Yang

  21. Summary • A list of issues should be paid attention to when making proposals to 11s • Open Questions: • Is this useful to TGs? • Anything here that must be addressed by 11s as hard (minimum) requirements? • How do we intend to measure the Mesh Media Access Coordination Function performance of the proposals? • Should we derive some simulation scenarios from this list so that different aspect of the performance can be evaluated? Lily Yang

  22. References [1] 11-04-0749-00-000s-suggested-major-functional-components-802-11s.ppt [2] 11-04-0968-05-000s-issues-for-mesh-media-access-coordination-component-in-11s.doc Lily Yang

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