Message relay in disconnected ad-hoc networks

An ad-hoc network is formed by a group of mobile hosts upon a wireless network interface. Previous research in communication in ad-hoc networks has concentrated on routing algorithms which are designed for fully connected networks. The traditional approach to communication in a disconnected ad-hoc network is to let the mobile computer wait for network reconnection passively. This method may lead to unacceptable transmission delays. We propose an approach that guarantees message transmission in minimal time. In this approach, mobile hosts actively modify, their trajectories to transmit messages. We develop algorithms that minimize the trajectory modifications under two different assumptions: (a) the movements of all the nodes in the system are known and (b) the movements of the hosts in the system are not known.