Cross-Layer Optimization for Energy-Timeliness Tradeoff in TDMA Based Sensor Networks

Energy efficiency is a critical issue in wireless sensor networks. Energy consumption can be saved by using a lower transmission power, but this also increases the channel error rate and the energy consumption on packet retransmission, as well as the packet delay. In this paper, taking retransmission in physical layer into account, we propose a cross-layer strategy to explore the tradeoff between energy efficiency and packet timeliness in time division multiple access (TDMA) based sensor networks, by transmission power allocation and routing path selection schemes. We divide the problem into two optimization sub-problems of power allocation and path selection in each layer, and propose lower-complexity algorithms for each sub-problem. Numerical results show that a tradeoff exists between energy efficiency and packet timeliness, and energy consumption can be significantly reduced while satisfying the packet timeliness constraint by using the proposed strategy.