QoS Challenges and QoS-Aware MAC Protocols in Wireless Sensor Networks

Wireless Sensor Networks (WSN) comprises a group of tiny sensor nodes which sense the environment and transfer the processing information through wireless links. Environmental monitoring, Healthcare, Target detection and Tracking, Industrial Process Monitoring, Intelligent Buildings, and Disaster Relief Operations are some of the applications of WSN. An efficient deployment of WSN depends on successful implementation of Quality of Service (QoS). Providing QoS in WSN refers that a set of service requirements includes bandwidth, throughput, delay, energy consumption, etc. , to be satisfied when transmitting a packet from source to destination. QoS mechanism provides reliable and timely information in WSN. Providing QoS support is a challenging issue due to highly resource constrained nature of sensor nodes, unreliable wireless links, harsh operation environments, and the dynamic behavior of sensor nodes. QoS can be achieved in all the Open Standard Interconnection (OSI) layers. But, improving QoS in MAC layer is important because without the assumption of MAC layer QoS cant be achieved in Network or Transport layer. This paper explains QoS challenges and QoS aware MAC Protocols which achieves energy efficiency and service differentiation.