Reducing inter-cluster TDMA interference by adaptive MAC allocation in sensor networks

The paper presents a self-reorganizing slot allocation (SRSA) mechanism for TDMA based medium access control (MAC) in multi-cluster sensor networks. The aim is to provide a MAC layer protocol that can reduce inter-cluster TDMA interference without having to use spectrum expensive and complex wideband mechanisms such as CDMA or FDMA. The primary contribution of the paper is to demonstrate that, with adaptive slot allocation, it is possible to reduce inter-cluster interference under low loading conditions. The second contribution is to design a feedback based adaptive allocation reorganization protocol that can significantly reduce the inter-cluster interferences without relying on any global synchronization mechanisms. We present the design of SRSA and provide a simulation based characterization of the protocol in comparison with TDMA-over-CDMA, TDMA with random slot allocation and CSMA MAC protocols.