Improving the network lifetime with energy-balancing routing: Application to RPL

The devices composing Wireless Sensor Networks (WSN) are very limited in terms of memory, processing power and battery. We need efficient routing algorithms to ensure a long lifetime of the WSN. However, many solutions focus on minimizing the average energy consumption of all the nodes. Since the lifetime is rather given by the death of the first node or by the disconnection of the network, these solutions are currently insufficient. Here, we have rather chosen to focus on identifying the energy bottlenecks (i.e., the nodes that are more likely to be the first ones to run out of energy). Minimizing their energy consumption will surely improve the network lifetime. We define here the Expected LifeTime (ELT) routing metric to estimate the lifetime of these bottlenecks. We take into account both the amount of traffic and the link reliability to estimate how much energy such a bottleneck consumes on average. Moreover, we apply this metric to the RPL architecture, the de facto routing standard in the Internet of Things. We construct the Directed Acyclic Graph structure based on this ELT criteria while avoiding the creation of loops.