Unicast routing in mobile ad hoc networks: Present and future directions

Recent advances in portable computing and wireless technologies are opening up exciting possibilities for the future of wireless mobile networks. A mobile ad Hoc network (MANET) is an autonomous system of mobile routers (and associated hosts) connected by wireless links-the union of which form an arbitrary graph. The routers are free to move randomly and organize themselves arbitrarily; thus, the network's wireless topology may change rapidly and unpredictably. At present, ad Hoc unicast routing is a focus of research work. In this article, we will provide a detailed description of issues and protocols for unicast routing in MANETs. The future directions in research are going to be discussed, too. We hope that the discussion presented here will be helpful to application developers in selecting an appropriate unicast protocol and pave the way for future research.