SCL: A Cross-Layer Protocol for Wireless Sensor Networks

Abstract

Wireless Sensor Networks are a new class of distributed systems that are used to collect information from the physical area they inhabit. They usually consist of a large number of low-power wireless sensor nodes or motes with limited computation power and memory for sensing of the environment. Energy efficiency and real-time response are important features in the design of sensor networks. Many communication protocols at different layers have been proposed to reduce the energy consumption of wireless sensor networks. In this thesis, the main objective is to present a method to improve the performance of wireless sensor networks in terms of throughput and latency. We use a hybrid access protocol based on a clustering routing scheme, named SCL (Sigma Cross-Layer) protocol. The main idea is to use a hybrid access protocol to deal with the intra-cluster communications after partitioning the whole network into several clusters. The access scheme incorporates both contention-based (e.g., CSMA) and contention-free (e.g., TDMA) medium access schemes. TDMA is used when the networks are under high traffic load or congestion, and CSMA is used during the clusters’ setup phase as well as low contention scenarios. In summary, the results provided by NS-2 simulations showed the proposed scheme, compared to other scheme which uses TDMA stand-alone, improves the throughput and reduces the latency of sensor networks.