A comparative study of energy efficient mac protocols in wireless sensor networks

Abstract

This paper conducted a comparative study on energy-efficient routing protocols in wireless sensor networks. Several MAC protocols based on channelization and random access were considered in this study. They include modified Carrier Sense Multiple Access with Collision Avoidance, Medium Access Control (CSMA/CA MAC), Carrier Sense Multiple Access with Collision Avoidance, Medium Access Control (CSMA/CA MAC) and modified Aloha MAC protocols. Matlab/Simulink modeling and simulation environments together with state flowchart applications were used to analyze energy-efficient routing protocols. The application of state flow diagrams and state flowcharts was extensively used for the logical contents of the MAC protocols. This paper improved the backoff time of the CSMA MAC protocol immediately after an Ack is not received. In the modified CSMA/CA MAC protocol, the average backoff period is typically doubled on each successive transmission attempt due to a failed transmission for a particular packet. The results obtained in this study showed that for radio node 1, peak backoff time at 0.02 sec of modified CSMA/CA, CSMA/CA and modified Aloha are 995 sec, 300 sec and 190 sec respectively., for radio node 2,  peak backoff time at 0.02 sec of modified CSMA/CA, CSMA/CA and modified Aloha are 560 sec, 190 sec and 140 sec respectively  and for radio node 3, peak backoff time at 0.02 sec of modified CSMA/CA, CSMA/CA and modified Aloha are 190 sec, 50 sec and 30 sec respectively. The modified CSMA/CA MAC protocol was shown to be more efficient in terms of energy consumption, traffic delays, and throughput than the modified Aloha MAC and the CSMA/CA MAC protocols. The implications of a higher backoff time in modified CSMA/CA suggest improved channel utilization and reduced collision probability at the cost of increased transmission latency, ultimately resulting in more stable and efficient network performance.