Abstract : Since the last ten years, wireless sensor networks attract considerable research interests. The limited energy of sensor, the embedded constraints and the communication restric- tions make WSN a very challenging system. Every protocols and applications should be energy efficient. Many efforts have been made to propose energy saving protocols in WSN through activity scheduling, energy-efficient MAC protocols, energy-aware rout- ing protocol, temporal and spatial data aggregation schemes at the application layer. However both control packets and beacons remain even if there are a waste of energy. Beacon-less geo- routing protocols are a piece of work to improve considerably the sensor lifetime but classical approaches do not work under realistic radio assumptions due to the planarization strategies. In this paper, we present a new beaconless routing protocol called Pizza-Forwarding without any assumption on the radio environment: neither the radio range nor symmetric radio links nor radio properties (shadowing, ...) are assumed or restricted. A classical greedy mode is proposed. To overcome the hole problem, packets are forwarded to an optimal node in the two hop neighbor following a reactive and optimized neighborhood discovery. Simulation results are proposed to highlight the delivery ratio and the energy consumption.
