Power Management for Acoustic Underwater Networks

•Our scheme combines an asynchronous approach, where nodes work ontheir own wake up schedules without synchronized clocks, with an on-demand scheme where two acoustic modem are used.•It uses a low power acoustic modem emitting beacons periodically tosearch for contacts within its neighborhood and remaining in sleep modefor the rest of the time.•A high power acoustic modem remains in sleep mode until there is dataready to be delivered or received from another node.•Once data exchange has taken place the high power acoustic modem onceagain enters the sleep mode.•ThehighandthelowpoweracousticmodemspropertiesareshowninFig.3.•Two alternative operations are considered in this scheme: neighbor dis-covery in which a node wakes up to search about neighbor nodes for dataforwarding, and data delivery in which data is exchanged among nodes.Fig. 3 denotes a sce-nario when node Aand node B are bothstillintheiractivebea-con periods and startto exchange data.