Adaptive TDMA Slot Assignment Using Request Aggregation in Wireless Sensor Networks

TDMA-based MAC protocols are considered an energy efficient solution to prolong wireless sensor network lifetime. However, their drawbacks such as complexity of slot assignment and schedule maintenance and adaptivity to varying traffic conditions are yet to be handled in an efficient way. In this paper we present On-demand Convergecast Scheduling-based (OCS) MAC protocol. It is a centralized and adaptive multihop scheduling-based TDMA protocol which supports convergecast applications. OCS adopts a novel requests aggregation mechanism for adaptive slot assignment such that time slots are assigned on-demand to currently active sources as well as relays. The performance of OCS is compared to existing protocols based on simulations in ns-2. Results show that OCS outperforms protocols such as Z-MAC, S-MAC, and others in terms of delay, throughput and energy efficiency. (C) 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of [name organizer]