Hybrid MAC protocol design to achieve energy efficiency and low latency for time critical applications

Abstract

The ubiquitous plug and play characteristics of commercially available open source hardware paved way for the development of smart wireless sensor network. Sensor nodes have limited amount of battery power, therefore energy efficient protocol design is very much essential for networked embedded systems. There are some challenges, design principles and technical approaches required to address time critical applications. The challenges are due to its wireless nature, limited resource, distributed architecture, traffic density variations, average end-to-end delay and dynamic network topology. In this thesis work, the performance of various conventional Medium Access Control (MAC) protocol design such as Sensor MAC newline(SMAC), Time out MAC (TMAC), Zebra MAC (ZMAC), Emergency Response MAC (ER - MAC), ContikiMAC, Contiki Cross MAC (CxMAC), NullMAC and Advertisement MAC (ADV - MAC) have been analysed. To meet the above-mentioned challenges a hybrid Emergency Threshold- Medium Access Control protocol (ET - MAC) is proposed, which targets on advanced home automation and basic healthcare informatics. The ET MAC deploy nodes, which adopts a TDMA approach for collision - free slots during high traffic density. Further, CSMA approach adopted during low traffic conditions to avoid collision, to have low latency and high channel utilization factor. ET - MAC emphasizes primary concern for critical parameters like emergency data and low end to -end delay. Parameters such as residual energy, energy efficiency and throughput are specified as secondary concern. newline newline