Partner selection algorithms for improving the network lifetime and decreasing the overall transmit energy expenditure in a wireless sensor network

Cooperative relaying may be used to improve the lifetime of a wireless sensor network and decrease the total transmit energy expenditure in a wireless sensor network where the nodes are constrained by limited energy and computational capabilities. In networks with no special relays, ordinary nodes can assist each other to deliver the messages of one another. Different methods to select the partner nodes have been presented in literature. We compare the performance of some of the most simple algorithms along with two proposed modified schemes using two different practical scenarios. We consider the problems of lifetime improvement and total energy reduction of a network in an IEEE 802.15.4 compatible environment. We also compare the computational complexity of such algorithms. It can be observed that while the optimum algorithms are computationally very demanding especially if the number of nodes is large, the performance of other algorithms depends on the channel conditions and for certain scenarios, their performance is comparable to optimum algorithms. Thus an assessment of the expected channel conditions can be a prerequisite before the selection of an appropriate pairing algorithm is made. Moreover, it is also shown that for certain schemes, the requirement of an improved network lifetime does not translate to a decrease in the overall transmit energy and vice versa.