HCRS: A Routing Scheme for Ad Hoc Networks as a QoS Guarantee Primitive

With the support of multimedia and real-time services in ad hoc networks, the design of a routing scheme supporting quality of service (QoS) is extremely challenging because of mobility, limited power, unpredictable radio channel behavior and constrained bandwidth, which is still an open issue for ad hoc networks at present. It was found that most present schemes do not consider network parameters other than the shortest path and bandwidth for routing decisions. This paper provides a routing scheme guaranteed QoS with multiple constraints for ad hoc networks: Hierarchical Cluster-Based Routing Scheme (HCRS). HCRS consists of two algorithms for intra- and inter-clusters aimed at different targets respectively. For inter-clusters routing, HCRS takes high-efficient and simple algorithm to guarantee stable route, while for intra-clusters routing, ant colony algorithm is very suitable to do this due to its flexibility and low computation complexity. Nevertheless, because of the defects of slow-convergence and stagnation phenomenon, we improve the ant colony algorithm to calculate different required QoS routes with multiple constraints. Here we take time delay, delay jitter, bandwidth, packet loss rate and cost into consideration. At last, the simulation results prove that HCRS is more effective.