LF-GFG: Location-Free Greedy-Face-Greedy Routing With Guaranteed Delivery and Lightweight Maintenance Cost in a Wireless Sensor Network With Changing Topology

The topology of a wireless sensor network changes as some sensors run out of power, fail, or join the network. In this paper, a delivery-guaranteed location-free routing protocol, termed LF-GFG, is proposed for a wireless sensor network with changing topology. We first describe the network multivalued embedding protocol to map each node and each link in the network to multiple virtual nodes and multiple virtual links, respectively, to constitute a virtual network in a plane and demonstrate the virtual network planarization protocol to obtain the connected spanning planar subgraph of the virtual network. Then, LF-GFG forwards a packet using the greedy-face-greedy (GFG) algorithm based on the virtual network and the connected spanning planar subgraph. As the network topology changes, the maintenance scheme reconstructs a connected spanning planar subgraph of the virtual network, using just local information, only if the spanning planar subgraph becomes disconnected. Thus, unlike existing location-free routing protocols, LF-GFG demands only lightweight maintenance costs as the network topology changes due to node addition or removal. Simulations in the network simulator NS-2 show that LF-GFG has good performance in terms of the construction message overhead, the maintenance time and message overhead, and the packet delivery rate while ensuring moderate routing latency costs.