A low-latency and energy-efficient algorithm for convergecast in wireless sensor networks

In wireless sensor networks (WSN) the process of dissemination of data among various sensors (broadcast) and collection of data from all sensors (convergecast or data aggregation) are common communication operations. With increasing demands on efficient use of battery power, many efficient broadcast tree construction and channel allocation algorithms have been proposed. Generally convergecast is preceded by broadcast. Hence the tree used for broadcast is also used for convergecast. Our research shows that this approach is inefficient in terms of latency and energy consumption. In this paper we propose a heuristic solution for the problem of minimum energy convergecast which also works toward minimizing data latency. This algorithm constructs a tree using a greedy approach where new nodes are added to the tree such that weight on the branch to which it is added is less. The algorithm then allocates direct sequence spread spectrum or frequency hopping spread spectrum codes. Simulation results show that energy consumed and communication latency of our approach is lower than some of the existing approaches for convergecast. We have then used our algorithm to perform broadcast. Surprisingly our results show that this algorithms performance for broadcasting is better compared to other broadcast techniques.