Performance Enhancement of IEEE 802.11e using DIPO/MOHD Backoff Mechanism

An analytical formulation of the saturated throughput enhancement of IEEE 802.11e using double increment plus one/ minus one half decrement (DIPO/MOHD) backoff mechanism for multiclass traffic is presented The analytical framework is formulated for N classes. The state transition diagram for the ith priority class is modeled by a two-dimensional discrete-time Markov chain One dimension of the Markov chain is for the backoff stage, and the second dimension is for the value of the backoff counter. The backoff stage moves to its previous backoff stage after a successful packet transmission and not back to the backoff stage 0 as in IEEE 802. lie. The advantages of this backoff mechanism are that it is easy to be implemented and can enhance the saturated throughputs. Numerical results of the saturated throughput corresponding to typical parameter values are presented The results show that the total saturated throughput using DIPO/MOHD can be better than that of IEEE 802. lie by up to 19%.