Half binary exponential increment double decrement back-off algorithm to enhance the saturated throughput of IEEE802.11 wireless LAN

Abstract

        In wireless local area network (WLAN), the back-off algorithm is used to reduce the collided packets in carrier sense multiple accesses with collision avoidance protocol (CSMA/CA).  Normally, the collided packets occur when two or more packets are sent in the same timeslot.  This research proposes a new back-off algorithm in retransmission process for improving the saturated throughput of IEEE802.11 WLAN.  A proposed scheme is called half binary exponential increment double decrement (HBEIDD) back-off algorithm. The throughput performance of a proposed algorithm is compared with four existing back-off techniques namely: double increment double decrement (DIDD), exponential increment exponential decrement (EIED), binary exponential increment half decrement (BEIHD), and random increment binary exponential decrement (RIBED) back-off algorithms.  The accuracy of all back-off algorithms is compared in a discrete time Markov chain model in fixed back-off states and contention window (CW) sizes.  Numerical results show that the saturation throughput of HBEIDD back-off algorithm is more stable than the existing back-off techniques under high traffic load condition.