Date Added: Nov 2012
Contention based bandwidth request mechanism is suggested for best effort services in WiMAX networks. The design of contention mechanism depends on the error model that reflects the transmission failure. In this paper, the authors have developed an error model by integrating the collisions due to contention, unavailability of bandwidth and channel error. The conventional Exponential Increase and Exponential Decrease (EIED) backoff witnessed low contention efficiency and high access delay with the proposed error model. Hence, they modify the EIED scheme by computing the backoff factors with average contention window and estimating the response time to reduce the waiting time of stations.