Open AccessAdapting physical carrier sensing to maximize spatial reuse in 802.11 mesh networks
Author(s) -
Zhu Jing,
Guo Xingang,
Lily Yang L.,
Steven Conner W.,
Roy Sumit,
Hazra Mousumi M.
Publication year - 2004
Publication title -
wireless communications and mobile computing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.42
H-Index - 64
eISSN - 1530-8677
pISSN - 1530-8669
DOI - 10.1002/wcm.264
Subject(s) - computer science , throughput , reuse , mesh networking , computer network , interference (communication) , channel (broadcasting) , distributed computing , physical layer , topology (electrical circuits) , network topology , wireless , telecommunications , ecology , mathematics , combinatorics , biology
Spatial reuse in a mesh network can allow multiple communications to proceed simultaneously, hence proportionally improve the overall network throughput. To maximize spatial reuse, the MAC protocol must enable simultaneous transmitters to maintain the minimal separation distance that is sufficient to avoid interference. This paper demonstrates that physical carrier sensing enhanced with a tunable sensing threshold is effective at avoiding interference in 802.11 mesh networks without requiring the use of virtual carrier sensing. We present an analytical model for deriving the optimal sensing threshold given network topology, reception power and data rate. A distributed adaptive scheme is also presented to dynamically adjust the physical carrier sensing threshold based on periodic estimation of channel conditions in the network. Simulation results are shown for large‐scale 802.11b and 802.11a networks to validate both the analytical model and the adaptation scheme. It is demonstrated that the enhanced physical carrier sensing mechanism effectively improves network throughput by maximizing the potential of spatial reuse. With dynamically tuned physical carrier sensing, the end to end throughput approaches 90% of the predicted theoretical upper‐bound assuming a perfect MAC protocol, for a regular chain topology of 90 nodes. Copyright © 2004 John Wiley & Sons, Ltd.