Geographic Adaptive Fidelity (GAF): GAF [15] is an energy-aware routing protocol primarily
proposed for MANETs, but can also be used for WSNs because it favors energy conservation.
The design of GAF is motivated based on an energy model [16, 17] that considers energy
consumption due to the reception and transmission of packets as well as idle (or listening) time
when the radio of a sensor is on to detect the presence of incoming packets. GAF is based on
mechanism of turning off unnecessary sensors while keeping a constant level of routing fidelity
(or uninterrupted connectivity between communicating sensors). In GAF, sensor field is divided
into grid squares and every sensor uses its location information, which can be provided by GPS or
other location systems [16, 18, 19], to associate itself with a particular grid in which it resides.
This kind of association is exploited by GAF to identify the sensors that are equivalent from the
perspective of packet forwarding