A Novel Systematic Resource Transfer Method for Wireless Sensor Networks

The use of wireless sensor networks for gathering environmental and safety-critical data in real time is increasing at a rapid rate. Some of the main criteria in designing sensor network architectures are energy-efficiency, self-management and self-healing. However, most protocols for data gathering and routing in sensor networks implicitly assume a regular rate of data gathering by individual nodes. While this is sufficient for sensing parameters that change slowly over time, individual nodes in a small part of a network may need to increase the rate of data gathering considerably for reporting important data in real-time. Though CSMA protocols can report increasing amount of data in theory, increased contention for the wireless medium in a small part of the network usually results in increased message collision and retransmission. In this paper, we present a novel TDMA protocol for transferring time slots from one part of the network to another part to support non-uniform and reactive sensing in different parts of a network. We discuss the design of this protocol and show that it performs much better compared to CSMA protocols both in terms of energy-efficiency and supporting nonuniform sensing.