Geographic Routing(GR)algorithms require nodes to periodically transmit HELLO messages to allow neigh- bors to know their positions(beaconing mechanism).Beacon-less routing algorithms have recently been proposed to reduce the control overheads due to these messages.However,existing beacon-less algorithms have not considered realistic physical layers.Therefore,those algorithms cannot work properly in realistic scenarios.In this paper we present a new beacon- less routing protocol called BOSS.Its design is based on the conclusions of our open-field experiments using Tmote-sky sensors.BOSS is adapted to error-prone networks and incorporates a new mechanism to reduce collisions and duplicate messages produced during the selection of the next forwarder node.We compare BOSS with Beacon-Less Routing(BLR) and Contention-Based Forwarding(CBF)algorithms through extensive simulations.The results show that our scheme is able to achieve almost perfect packet delivery ratio(like BLR)while having a low bandwidth consumption(even lower than CBF).Additionally,we carried out an empirical evaluation in a real testbed that shows the correctness of our simulation results. Geographic Routing (GR) algorithms require nodes to appropriately transmit HELLO messages to allow neigh- bors to know their positions (beaconing mechanism) .Beacon-less routing algorithms have recently been reduced to control the overheads due to these messages.However, existing beacon -less algorithms have not considered working in physical layers. Here, those algorithms can not work properly in real scenarios. In this paper we present a new beacon- less routing protocol called BOSS.Its design is based on the conclusions of our open-field experiments using Tmote-sky sensors. BOSS is adapted to error-prone networks and incorporates a new mechanism to reduce collisions and duplicate messages produced during the selection of the next forwarder node. We compare BOSS with Beacon-Less Routing (BLR) and Contention-Based Forwarding (CBF) algorithms through extensive simulations.The results show that our scheme is able to achieve almost perfect packet delivery ratio (like BLR) while having al ow bandwidth consumption (even lower than CBF) .Additionally, we carried out an empirical evaluation in a real testbed that shows the correctness of our simulation results.