The Simulation Analysis Of Adaptive Backoff Exponent Algorithm For IEEE 802.15.4 Network On 2.4GHz Band

The IEEE 802.15.4 is a new personal wireless area network standard designed for low data rates applications. IEEE 802.15.4 specifies MAC layer for contention access medium based on CSMA-CA mechanism. It often leads to degradation of system performance at congestion scenarios, due to higher number of collisions. In this thesis, a study of the Adaptive Backoff Exponent management of slotted CSMA-CA to the current implementation based on a decision criterion is referred. It adjusts the backoff exponent of node devices corresponding to their contributions to the network traffic by beacon indications, which decreases the probability of devices choosing identical backoff slots to sense the channel.A star topology network with the implementation of ABE algorithm on 2.4GHz band is simulated with NS-2. By comparing with the results of IEEE 802.15.4 original slotted CSMA-CA simulations, its balance of contention access medium and fine tuning potential packet collisions and drops are presented, indicating an overall improvement in network performance, hence better throughput, delivery ratio, energy consumption and fairness.