An adaptive approach to group communications in multi hop ad hoc networks

The diverse nature of MANETs makes it almost impossible for a single routing protocol to perform well under a wide range of operating conditions. Therefore the solution may be to adopt an adaptive strategy to routing and the co-existence and interoperability of different routing protocols. Considering that MANETs are generally deployed in mission critical applications the adaptive protocol should be capable of providing high reliability and timeliness guarantees in the presence of mobility. To this end we develop an adaptive flooding protocol in which nodes can dynamically switch routing mechanisms based on their perspective of network conditions. We use relative velocity as the switching criterion. Each node periodically computes its velocity relative to that of its neighbor set and based on its computation switches to one of the three modes, i.e. scoped flooding, plain flooding or hyper flooding modes. Simulations using our adaptive protocol under various realistic scenarios have shown that such protocols provide impressive benefits and can be used as the basis for developing adaptive, integrated routing techniques for MANETs of the future.