Improved backoff mechanism for IEEE 802.15.4 MAC protocol

Abstract

Concerning the impact on network performance of the mobile nodes and the constantly changing data transmission rate,the authors proposed a new backoff scheme for IEEE802.15.4,which used Probability Judgment based on Network Load and Exponentially Weighted Moving Average(PJNL_EWMA) method.According to a real-time monitoring of current network status by probability judgment of network load,this method dynamically adjusted backoff exponent by EWMA when Carrier Sense Multiple Access with Collision Avoidance(CSMA/CA) began.Compared with the IEEE802.15.4 standard protocol and MBS(Memorized Backoff Scheme) + EWMA algorithm,the simulation experiments on NS2 platform show that the PJNL_EWMA algorithm not only improves the throughput of the network,but also reduces the packet loss rate and the collision ratio,significantly improving the network performance.