A novel multi-relay selection algorithm based on genetic algorithm (GA) in dual-hop decode- and-forward cooperative network is presented. The quality of service is expressed by the condition that the SNR of destination should be larger than 22R — 1 according to Shannon information capacity, in which R is its data-rate requirement.

Moreover, residual energy status parameter of the network using the total energy of each node along with [0, 1] indicator are modelled in order to prolong the network lifetime. The optimization problem is to minimize the residual energy under the SNR condition. It is a NP-complete one, and a general GA is exploited to search out the solution. Simulation results show that the proposed algorithm can preserve the network lifetime much longer than opportunistic relay.