EQoSA: Energy and QoS aware MAC for wireless sensor networks

This paper presents a general framework for adaptive Energy and QoS Aware (EQoSA) MAC protocol for wireless sensor networks. It is a scheduling based MAC protocol assuming a steady state network behavior. Similar to previous works, the time is divided into rounds and each round starts with a setup phase followed by a number of sessions. Each session starts with a contention window followed by a number of slots reserved for those users who expressed their wishes to transmit packets and the cluster head approved their assignment. The proposed protocol has two unique features; the dynamic size of each session and the ability to accommodate bursty sensors by allocating more than one data slot in each session. EQoSA is so general to accommodate a wide range of wireless sensor networks applications. A discrete event driven simulation is extensively run to evaluate the proposed protocol. The proposed protocol is examined against Bit-Map MAC protocol (a modified LEACH) and it shows an outstanding improvement both in end-to-end packet delay as well as the total consumed energy. These important results make EQoSA a viable MAC protocol for real time applications such as video and imaging applications.