A Framework for Scalable Hierarchical Routing in Mobile Ad Hoc Networks

The theoretical performance advantages of dividing a network into independent routing domains is well known however, the actual benefits are hard to quantify and are often not sufficient to outweigh the added complexity. Justification of domains is especially hard in mobile ad hoc networks MANETS because reconfiguration overhead and the use of single interface routers increase. Nevertheless, the authors believe that with the right domain configuration and inter-domain routing protocol, they can get better performance using hierarchical than flat routing, especially in heterogeneous and dynamic networks. This paper proposes a framework for scalable routing in MANETs based on auto-configured optimized routing domains and an enhanced inter-domain routing scheme. To minimize overall overhead, the inter-domain routing protocol exploits existing messages needed for domain maintenance. The framework allows different routing protocols to run in each domain. OPNET simulations show the benefits of the proposed approach using OLSR for intra-domain routing. The results show significant reduction in protocol overhead, increased route stability, and increased route availability in a dynamic heterogeneous network.