A braided routing mechanism to reduce traffic load's local variance in wireless sensor networks

Many-to-one wireless sensor networks suffer from an extreme variance of energy consumption due to diverse traffic load within the network nodes. Sensor nodes close to the sink consume significantly more energy than the farther ones, resulting in the energy hole problem (i.e., global variance). In addition, even nodes located at the same distance from the sink experience different traffic load with each other (i.e., local variance). The uneven distribution of traffic load, both globally and locally, results in a severe shortening of the time until the first node runs out of battery. This work focuses on balancing the traffic load of equally-distant from the sink nodes by sharing each one's load among its next-hop neighbors. Eventually, packets are traveling from a node to the sink by following interlaced paths. The proposed routing mechanism, called braided routing, is a simple one and can be applied over any least-cost routing policy, incurring a negligible overhead. Simulation results show that the local variance of energy consumption is reduced about 70-80% on average while the time until the first nodal loss can be prolonged more than twice in many cases.