3DGR Protocols Design Philosophy
Similar to traditional 2D geographic routing (2DGR) protocols, 3DGR protocols have two operational modes: greedy mode (the routing is therefore called greedy routing) and recovery mode (also called bypass mode; the routing is therefore called recovery routing or bypass routing). Generally, 3DGR operates in either greedy mode when it can find a neighbor closer to the destination than the current node, or recovery mode to route data packets once encountering a routing hole, where such a candidate closer than the current forwarder to the destination does not exist. In addition, 3DGR protocols are based on the following principles.