A solution to outdated neighbor problem in wireless sensor networks

Hello protocol is widely used in geographic routing protocols to obtain and maintain neighbor table. However in highly dynamic networks, the information stored in the neighbor table is often outdated causing retransmissions and rerouting. A novel Two-hop Hello protocol (T-Hello) is proposed aiming to improve the accuracy of neighbor table. By exchanging beacon messages within two-hop scope, location information can be obtained even if a neighbor node has moved out of communication range, so that the corresponding entry in neighbor table can be removed explicitly rather than waiting for time out. The conclusion is that the T-Hello protocol can shorten the lifetime of outdated neighbors by 50%, and hereby improve the performance of GPSR protocol significantly.