Routing Information for Energy Management in WSNs

The main objective in a WSN application is to guarantee the transmission of information between different sensor nodes according to a pre-established routing protocol. Improving performance in terms of longevity, connectivity and robustness requires some consideration of constraints such as energy consumption, bandwidth and the optimal use of calculation and memory resources. The conception and implementation of a routing protocol can be influenced by several factors that must be addressed before it is possible to ensure efficient data communication. Among these factors, we can refer to the deployment of nodes in operational environments. Being dependent on the kind of applications under consideration, the deployment phase can greatly affect routing performances. It can be determinist and, in this case, sensor nodes are placed manually and the data are transmitted according to pre-determined routes from source nodes to the destination. This can also be done randomly by haphazardly distributing the nodes, as in ad hoc networks. In this case, an optimal classification of the network in clusters is highly necessary in order to guarantee connectivity and enable efficient energy management. Various studies have shown that the communication between nodes in restricted areas, i.e. clusters, provides better results in terms of energy consumption and bandwidth, and information routing can be guaranteed in this case through multiple hops. Moreover, the lifetime of a sensor node is strongly linked to the lifetime of its battery and the malfunctioning of one or several sensor nodes, due to battery failures or a lack of energy resources, can cause significant topological changes that require the network to be completely reorganized in order to ensure the rerouting of data. It is therefore important to consider the issue of how to manage energy consumption without a loss of performance and network precision, particularly in the case of a multi-hop WSN where each node can act as either a data transmitter or a simple router.