Adaptive Distributed Randomized TDMA Scheduling For Clustered Wireless Sensor Networks

This paper presents an adaptive distributed TDMA slot assignment algorithm, called A-DRAND, which is an improved version of DRAND in clustered wireless sensor networks where cluster heads need more slots and will be alternated afterwards by other cluster members for energy balance reason. It utilizes cluster info to allocate slots discriminately for different kind of sensor node and adapts its operation depending on the requirements of the application. The overhead is reduced significantly by reserving a special slot number range for slot reassignment. Simulation results show that running time and transmission cost of slot reassignment is only at most 1/m of that of all-participating assignment, where m is the proportion of cluster heads and other sensors with changing slots demanding in the network