Diffusing reservations: reducing call dropping in wireless networks

When there is competition for scarce resources, reserving capacity for delay-sensitive stream-oriented sessions, such as voice and video, increases the probability that the network will be able to meet the sessions´ performance requirements. Mobile wireless networks not only exhibit limited transmission capacity but also frequent connectivity changes, and hence sessions must compete for resources among a continually changing set of nodes. Assuming a session is likely to be rerouted through adjacent nodes, we propose diffusing reservations to neighboring nodes along the route, to increase the probability that a session will continue to obtain the necessary resources as its route changes. We consider three different algorithms to be executed by the neighboring nodes: actual reservation, simulated reservation, and no reservation, and via simulation compare their performance in terms of blocking and dropping rates for attempted sessions and overhead of control messages.