In the context of geographic routing in wireless sensor networks linked by fading communication channels, energy-efficient transmission is important to extend the network lifetime. To this end, we propose a novel method to minimize the energy consumed by one bit of information per meter and per second toward the destination in fading channels. Using the outage probability as a measure to maximize the amount of information delivered within a given time interval we decide energy-efficient geographic routing between admissible nodes in a wireless sensor network. We present three different approaches, the first is optimal and is obtained by varying both transmission rate and power, the other two are sub-optimal since only one of them is tuned. Simulation examples comparing the energy costs for the different strategies illustrate the theoretical analysis in the cases of log-normal and Nakagami shadow fading. With the method proposed it is possible to obtain significant energy savings (up to ten times) with respect to fixed transmission rate and power.

在通过衰落的通信通道链接的无线传感器网络中的地理路由中，节能传输对于延长网络寿命很重要。为此，我们提出了一种新颖的方法来最小化衰落信道中每米和每秒朝向目的地的一比特信息消耗的能量。使用中断概率作为在给定时间间隔内最大化传递信息量的度量，我们决定了无线传感器网络中可允许节点之间的节能地理路由。我们提出了三种不同的方法，第一种是最优的，并且是通过改变传输速率和功率来获得的，另外两种是次优的，因为它们中只有一种被调谐。比较不同策略的能源成本的仿真示例说明了对数正态和Nakagami阴影衰落情况下的理论分析。利用所提出的方法，相对于固定的传输速率和功率，可以获得显着的能量节省（多达十倍）。