Schedule length balancing for aggregated convergecast in multiple sinks wireless sensor networks

Tree is a widely used topology for Wireless Sensor Networks (WSNs). As Time Division Multiple Access (TDMA) eliminates collisions, it is a preferred channel access mechanism. Often multiple sinks are deployed in WSNs. Use of multiple sinks provides fault tolerance and load balancing. In tree based networks, every sink becomes root of exactly one tree. When node deployment is not uniform across the region, some trees become very dense and others are sparse. When scheduling is done, dense tree results in higher schedule length than the sparse one. For aggregated convergecast, schedule length minimization is an important objective. In this work, we have proposed an algorithm which allows every node to decide which sink (i.e. tree) to join such that schedule lengths of trees remain balanced. The proposed algorithm executes before actual scheduling algorithm. It is shown through simulations that proposed algorithm results in schedule length balancing and also reduction in schedule length.