Delay Analysis of IEEE 802.11 DCF with modified Binary Exponential Backoff

In the design of wireless networks the medium access control (MAC) protocols have a very high impact on the performance of the network. The IEEE 802.11 is widely accepted technology for the Wireless LANs has been used by wireless networks. Delay is one of the important parameter to measure the performance of the wireless networks. We give a delay analysis of the Distributed Coordination Function of IEEE 802.11 under modified Binary Exponential Backoff (BEB) Algorithm using Frequency Hoping Spread Spectrum (FHSS). In the modified BEB, initially the contention window size increases with the factor of √2 for first four collisions and after that for more collisions the size of contention window gets double. The size of contention window varies between CWmin and CWmax. Markov chain has been used for the analysis of IEEE 802.11 DCF for both modes basic and RTS/CTS. We have considered number of nodes and transmission probability to compute the delay for both the modes. The results show that the performance of RTS/CTS mode is better than the basic access mode. In this paper, we have numerically analyzed the IEEE 802.11 DCF by varying different parameters ( i.e. number of nodes, transmission probability etc.). KeywordsMedium Access Control, Distributed Coordination Function, Markov chain, Delay analysis