Establishment and Maintenance of a Delay Tolerant Network through Decentralized Mobility Control

In this paper we investigate the establishment and maintenance of a delay tolerant network through decentralized mobility control. A set of geographically dispersed wireless radio nodes wish to communicate with one another. These nodes are free to move about the environment and are not constrained to remain in direct communication range of one another. A second set of helper nodes exist in the environment that can form connected chains between nodes and that can ferry data back and forth between sensor nodes and/or other helper nodes. The mobility of the helper nodes is controlled based on local information about neighboring nodes and the communication flow through the network. A hierarchical approach is described in which helper nodes are assigned specific sensor nodes or regions of activity through resource allocation algorithms while communication flow through established links is maintained by decentralized control based on local measures only such as received signal strength or signal to noise ratio