Occupancy Estimation in the IEEE 802.11 Distributed Coordination Function

Abstract

IEEE 802.11 employs Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) as primary Medium Access Control (MAC) scheme, namely the Distributed Coordination Function (DCF). Throughput performance of DCF is very sensitive to the number of competing stations. In this paper, a methodology to estimate this number from run-time measurments is proposed. The explicit knowledge of occupancy status of an 802.11 Wireless network has several practical implications, as it can dynamically drive switching algorithms from Basic to RTS/CTS access model, as well as cell selection algorithms employing load balancing.