Combined contention and TDMA-based communication in wireless sensor networks

Wireless sensor networks usually consist of a large number of very small, energy-constrained sensor nodes. The nodes capture information from their immediate environment to send it to a destination node (sink) in a timely manner. This work proposes a combined contention and TDMA-based approach for load balancing and a discrete-time Markov model that allows to study the trade-off between energy consumption and transfer delay in clustered wireless sensor networks. Our investigations show that the length of the TDMA frame needs to be configured close to the minimum that is capable of transferring the offered load for optimizing energy efficiency and minimizing the delay.