Reservation based medium access control protocol for wireless sensor networks

Most of the proposed MAC and routing protocols for wireless sensor networks (WSNs) consider energy efficiency as the main objective and assume data traffic with unconstrained delivery requirements. However, applications such as rescue and disaster recovery, and tracking moving objects demand end-toend performance guarantees as the timely delivery of data is as important as energy efficiency. This paper presents a reservation based medium access control (MAC) for applications with different QoS priorities in a clustered WSN environment. The protocol is based on a combination of CDMA, TDMA and contention based access mechanisms. The protocol employs a slot assignment algorithm to handle adaptive resource allocation in a clustered environment. Simulations that demonstrate the feasibility of the proposed MAC protocol and the resource allocation is discussed.