Research Of Location Service In Multi-channel Ad Hoc Networks

Following the development of Ad Hoc networks technology, position-based routing protocols are increasingly concerned because there're more scalable. In position-based mobile Ad Hoc networks, before using efficient routing protocols to forward packet, the source node have to know the destination node's position, and such work is what the main function of location service.In this paper, we discuss several main routing protocols and location service schemes in Ad Hoc networks. After that, we present a location service scheme called MQLS(Mesh-Quorum Location Service). In MQLS scheme, network area is divided into many square grids. Each managing-unit, what is consisted of nine grids, is autonomous internally. A node, selected as a managing-node in each managing-unit, is used to save and update location information. Managing-nodes exchange the location information to carry out location update among managing-unit. The proposed scheme improves the managing-node competition and hand-off algorithm and use multi-channel model to increase the capacity of network.We use NS-2(Network Simulator-2) to simulate the MQLS-S(single-channel MQLS) scheme and the MQLS-M(multi-channel MQLS) scheme. Query Success Ratio, Query Length of Path, Query Packet Delivery Ratio, Query End-to-End Delay are the metrics we use to analyze our scheme. Simulations show that MQLS scheme is well performance. Compare to MQLS-S, MQLS-M has higher Query Packet Delivery Ratio. It shows that the proposed multi-channel assignment method decrease the packet collision and increase the capacity of network.