In the context of geographic routing in wireless sensor networks linked by probabilistic communication channels, energy efficient transmission is important to extend the network lifetime. presents a novel probabilistic forwarding approach for directed data transmission without route discovery. In this model, each message is required to reach the base station successfully with a predefined probability, hence sensor nodes which are located nearer to the base station need to relay messages with a certain relay probability. The relationship between the number of relaying nodes and relay probability is analyzed and the condition for relay probability to guarantee the success probability is obtained. We propose a novel methods profor and enprofor protocols are distributed and localized protocols. They can adapt to a topological change of the network and work robustly against individual node failure.. Simulation examples comparing the energy costs for the different strategies illustrate the theoretical analysis in the cases. With the method proposed it is possible to obtain a significant energy savings (up to ten times) with probabilistic transmission rate and power.