CSMA/SR Decentral Spatial Reuse Channel Access Algorithm for Wireless LAN

The upcoming IEEE 802.11ax standard renews the discussion on spatial reuse by parallel transmitting links. The standard uses carrier sense threshold level and transmit power adjustments to potentially improve performance of the network. Related work shows that allocating dedicated transmit power and rate settings per link is key to fully utilize spatial re-use potential. This paper discusses how to best apply such spatial reuse concepts to a decentral channel access protocol. A state time model reflects fundamental performance drivers and limits of the approach. The proposed CSMA/SR algorithm shows up as a good compromise between needed protocol overhead and achieved throughput improvement. An IEEE 802.11ax based simulation demonstrates a CSMA/SR system performance improvement up to 46 % compared to standard CSMA/CA.