The aforementioned route selection schemes either focus on minimizing total energy consumption, or maximizing the network operational lifetime; but none takes into account the varying transmission error probabilities across links. For reliable communication, packets transmitted over error prone links potentially entail multiple retransmissions. It is observed that the effect of energy reduction achieved by choosing a route with short range but large number of hops can be negated as the number of hops increases, due to increased number of retransmissions.
Since link characteristics significantly affect the energy consumption for reliable packet delivery, power-aware routing protocols must not only concern with node specific parameters, e.g., residual battery energy, but must also take into consideration the link specific parameters, e.g., error rate of the channel, in order to increase the operational lifetime of the network.