Cross-Layer Optimization of Data Transport for Wireless Sensor Networks
A Wireless Sensor Network (WSN) is composed of spatially distributed sensor nodes (possibly a large number of nodes scattered over a wide geographic area) which cooperatively monitor environmental conditions such as temperature, vibration, noise, and movement in order to accomplish a common purpose such as event detection, critical infrastructure monitoring, and surveillance, to name a few. WSN data may be simple scalar measurements or more recently multimedia (audio and image data in Wireless Multimedia Sensor Networks) in nature. The ability of the transport layer to transmit these data from the sensors to the sink nodes (or vice-versa) in a reliable and efficient manner is of utmost importance since WSN nodes have limited resources in terms of throughput, power, lifetime, communications and computing capabilities. A mechanism that can improve transmission efficiency in the data transport layer is intermediate caching which allows intermediate to cache packets and, if necessary, retransmit them towards the destination in order to reduce end-to-end retransmissions. The proposed research plan aims to explore the benefits and cross-layer interaction of intermediate caching in the transport layer for WSNs. The main goal of this PhD research is to study and develop efficient and effective data transport mechanisms for wireless sensor networks by employing intermediate caching through a cross-layer approach.