AS 802.15.4: A modified IEEE 802.15.4 standard for more reliable communication and utilization of inactive period using optimized sleep period

This paper proposes a redefined multiple access control (MAC) protocol of IEEE 802.15.4 standard, incorporating an adaptive synchronization algorithm with optimal sleep period. The modified standard, namely AS 802.15.4 provides better power consumption, reliability and synchronization among the sensors than the existing protocol. AS 802.15.4 MAC protocol is modelled using a four dimensional Markov chain using backoff stage, backoff counter, retransmission limits, and a new parameter namely number of sleep slots. Using the Markov chain we have calculated different performance metrics as reliability, data packet collision probability, data transmission failure probability, power consumption, throughput and average packet delay for comparison between the existing and redefined protocol. We have simulated our modified protocol in ns 2.35 to compare the simulation result with the calculated result of the performance metrics. The performance of modified protocol is compared with the existing protocol for different performance metrics. We observe that our modified MAC protocol gives significant better performance than the existing MAC protocol.