Mobility control and its applications in mobile ad hoc networks

Most existing localized protocols in mobile ad hoc networks, such as data communication and topology control, use local information for decentralized decision among nodes to achieve certain global objectives. These objectives include determining a small connected dominating set for virtual backbone and topology control by adjusting transmission ranges of nodes. Because of asynchronous sampling of local information at each node, delays at different stages of protocol handshake, and movement of mobile nodes, the local view captured at different nodes many be inconsistent and/or outdated and many not reflect the actual network situation. The former may cause "bad" decisions that fail to keep the given global constraint such as global domination and connectivity, and the latter may incur "broken" links, which in turn would ultimately cause the failure of the constraint. In this article we review some techniques that handle inconsistent and outdated local views. These techniques are illustrated using several well-known protocols in data communication and topology control.