ABSTRACT
Sensors are usually self-powered by batteries. The total energy of a sensor is on the order of 1 J.4 Some may have solar cells that can scavenge energy at about 1 J per day outdoors and 1 mJ per day indoors. Since it is impractical to recharge a depleted battery, energy-aware protocols are preferred. Among all the components,
the transceiver for transmissions and receptions accounts for a major portion of the power usage.5 This implies that power-efficient protocols have significant impacts on the network performance, and an energy-efficient routing protocol can dramatically elongate the network lifetime.
