Agent based TDMA schedule for wireless sensor networks

In this article, we proposed a fast, adaptive, and single frequency based TDMA MAC protocol for wireless sensor networks. TDMA is a collision free and fair protocol by its definition. It has few deficiencies but that can be overcome by introducing some intelligent mechanisms. The proposed protocol has two variants: sensor-TDMA and sensor-TDMA with Virtual Cluster Election (VCE). It uses light-weight smart agent (LSA) as a middleware. It is a thin software sublayer of MAC layer sitting at each node. It has different behavior if sitting on the node versus the cluster. LSA also controls virtual cluster actuation, push-based data transfer, and reshuffling of slots based on load conditions. As a result protocol adapts with various circumstances. The push-based scheme monitors the changes in data within certain window and pushes the data when threshold is reached. LSA also manages the slot donation which is only valid for single frame. This protocol is best suited for dynamic topology of sensor networks i.e. if nodes die or new nodes join the network, it adapts with it. Our simulation study shows the effectiveness of the proposed solution and improvements over the traditional TDMA protocol in terms of energy consumption, TMT (Theoretical Maximum Throughput), average queuing delay, and average latency.