QoS routing of multiple parallel paths in TDMA/CDMA ad hoc wireless networks

This paper investigates the QoS routing in TDMA/CDMA ad hoc networks. Since the network topology may constantly change and the available bandwidth is very limited in ad hoc networks, it's quite often to see a call is blocked when a path with required bandwidth cannot be found in the system. Therefore, we try to find multiple paths whose aggregated bandwidth can meet the bandwidth requirement and whose delays are within the required delay bound and then use the multiple paths in parallel for the QoS transmission of the call. This QoS routing we proposed can significantly reduce the system blocking probability and thus make a better use of network resources. We discuss the process of searching multiple parallel paths and proposed three heuristics (according to three parameters: property of maximum bandwidth, property of shortest path, property of maximum ratio of bandwidth to hops) to choose a group of paths whose total bandwidth satisfies the requirement. Some simulations have been conducted and the simulation results have demonstrated the deference of blocking rates gained by using the proposed three heuristics and also shown the proposed algorithms out-perform one existent on-demand algorithm.