Comparison Between Centralized And Distributed Coordination For TDMA Operation In Wireless Sensor Networks

We compare centralized and distributed approaches for the coordination of transmission slots of wireless sensors for collision-free time division multiple access (TDMA) operation. For the centralized coordination, we focus on the guaranteed time slot (GTS) mechanism of the IEEE802.15.4 standard. For the distributed coordination, we present results with the DESYNC algorithm and its recent time-frequency extension. The results are derived via measurements with real TinyOS wireless sensor nodes using the CC2420 transceiver and reveal that both approaches obtain comparable throughput per node, with the GTS mechanism obtaining higher throughput only for the smaller permissible superframe duration. Moreover, distributed coordination is by nature more robust and scalable as it does not have a single point of failure and it can be scaled to multi-channel operation; however, it requires higher startup delay in order to converge to the steady state of operation.