Energy–delay tradeoff in wireless multihop networks with unreliable links

Energy efficiency and transmission delay are very important parameters for wireless multihop networks. Numerous works that study energy efficiency and delay are based on the assumption of reliable links. However, the unreliability of channels is inevitable in wireless multihop networks. In addition, most of works focus on self-organization protocol design while keeping non-protocol system parameters fixed. While, very few works reveal the relationship between the network performance and these physical parameters, in other words, the best networks performance could be obtained by the physical parameters. This paper investigates the tradeoff between the energy consumption and the latency of communications in a wireless multihop network using a realistic unreliable link model. It provides a closed-form expression of the lower bound of the energy–delay tradeoff and of energy efficiency for different channel models (additive white Gaussian noise, Rayleigh fast fading and Rayleigh block-fading) in a linear network. These analytical results are also verified in 2-dimensional Poisson networks using simulations. The closed-form expression provides a framework to evaluate the energy–delay performance and to optimize the parameters in physical layer, MAC layer and routing layer from the viewpoint of cross-layer design during the planning phase of a network.