Two-dimensional Markov model for throughput analysis of IEEE 802.11 Distributed Coordination Function in non ideal channel with capture effects

Wireless technologies are emerging as an important component of our daily life. Distributed Coordination Function (DCF) is the basis of IEEE 802.11 WLAN MAC protocol, which uses Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol and binary slotted exponential back-off scheme. DCF implementation specified by the IEEE 802.11 standard reset the contention window (CW) to minimum value upon a successful transmission. Although the newCW is minimal the congestion level goes gradually to minimum, causing the node to probably waste time and channel bandwidth going through several collisions and retransmissions before reaching a CW value corresponds to the congestion level. This paper modifies the implementation to reduce the window to half its size after a successful transmission. The paper uses analytical and simulation analysis to show throughput improvements under ideal and non-ideal channel with channel induced errors and capture effect. When compared to the standard implementation, throughput has improved for both ideal and non ideal channel.