HHLS: A Hybrid Routing Technique for VANETs
In this paper, the authors propose a combination between a routing protocol Greedy Perimeter Stateless Routing (GPSR) and Hierarchical Location Service (HLS) that they denote Hybrid Hierarchical Location Service (HHLS). HLS and GPSR used to be combined in the original work with a direct method, i.e. GPRS takes care of routing packets and HLS is called to get the destination position when the target node position is not known or is not fresh enough. When a destination is quite far away from the sender, the exact position of the target is calculated, and an extra overhead is generated from sender to receiver. Their main purpose is to reduce this overhead in HHLS.