EDGE: A Routing Algorithm for Maximizing Throughput and Minimizing Delay in Wireless Sensor Networks

Wireless sensor networks are distributed event-based systems with severe energy constraints, variable quality links, low data-rate and many-to-one event-to-sink flows. Communication algorithms for sensor networks, such as directed diffusion, are designed to operate efficiently under these constraints. However, directed diffusion is not efficient in more challenging domains, such as video sensor networks, because of the high throughput and low delay requirements of multimedia data. Instead, we propose EDGE - a greedy algorithm based on directed diffusion that reinforces routes with high link quality and low latency, thus maximizing throughput and minimizing delay. ETX (Expected Transmission Count) is used as the metric for measuring link quality. This paper presents an improved method for computing aggregate ETX for a path that increases end-to-end throughput. Simulation results with CBR (constant bit rate) traffic show that our proposed distributed algorithm selects routes that give better throughput than those reinforced by standard directed diffusion, while maintaining low delay.