Braided Routing Technique to Balance Traffic Load in Wireless Sensor Networks

Many-to-one wireless sensor networks suffer from an extreme variation of traffic load between nodes. Sensor nodes near the sink consume much more energy than distant ones, resulting in the energy hole problem (global variation of load). In addition, even nodes located at the same distance from the sink experience very different traffic load with each other (local variation). This uneven distribution of traffic load, both globally and locally, results in a severe shortening of the time until first node runs out of battery. This work focuses on balancing the load of equally-distant nodes from the sink by sharing each one's load among its next-hop neighbors. Eventually, packets are travelling from node to sink by following interlaced paths. The proposed routing mechanism, called braided routing, is a simple one and can be applied over any cost-based routing, incurring a negligible overhead. Simulation results show that the local variance of load is reduced nearly 20-60% on average while the time until first death can be prolonged more than twice in many cases and the lifetime about 15%.