WinlabMadwifi → Pipeline MAC paper Discussion

Paper Title:

Cooperative Scheduling Via Pipelining in 802.11 Wireless Networks

Download ​pdf

Motivation

• Per packet Micro-scheduling need firmware/hardware(MAC) upgrade
• Macro-scheduling could be done in multiple packet basis peridodically, e.g 10ms.
• Cooperative scheduling extensions can be supported using a new layer on top of the existing MAC layer.

Features of Scheme

• each node conducts "global scheduling" based on "load infomation" of all other nodes.
  • the global scheduling determines a TDMA-like slot/bandwidth allocation
• 3 stages, 2 ½ pipelineing:
  • estimation — load exchange — scheduling
  • equivalent to predict — signaling — access
• Kernel code modification
  • packet_tx
  • packet_rx
  • stop_queue
  • wake_queue

Weakness

• a solution for IEEE 802.11 Wireless LAN, not a solution for multi-hop
• no solution for signalling loss, wrong scheduling automatically fades out in next cycle.
• rely on AP's beacon to sync all nodes.