Inlthelcontextloflgeographiclroutinglinlwirelesslsensorlnetworksllinkedl byl probabilisticl communicationl channels,l energyl efficientl transmissionl islimportantltolextendlthelnetworkllifetime.presentslalnovellprobabilisticl forwardingl approachl forl directedl data transmissionl withoutl routel discovery.l Inl thisl model,l eachl messagel isl requiredl tol reach thel basel stationl successfullyl withl al predefinedl probability,l hencel sensorl nodesl which arel locatedl nearerl tol thel basel stationl needl tol relayl messagesl withl al certainl relay probability.l Thel relationshipl betweenl thel numberl ofl relayingl nodesl andl relayl probabilityl isl analyzedl andl thel conditionl forl relayl probabilityl tol guaranteel thel success probabilityl isl obtained. Wel proposel al novell methodsl ProForl andl EnProFor l protocolsl arel distributedl andl localizedl protocols.l Theyl canl adaptl tol al topologicall changel ofl thel networkl andl workl robustlyl againstl individuall nodel failure..l Simulationl examplesl comparingl thel energyl costsl forl thel differentl strategiesl illustratel thel theoreticall analysisl inl thel cases.l Withl thel methodl proposedl itl isl possiblel tol obtainl al significantl energyl savingsl(upltoltenltimes)lwithlprobabilisticltransmissionlratelandlpower.