Routing with Probabilistic Delay Guarantees in Wireless Ad-Hoc Networks

In many wireless ad-hoc networks it is important to find a route that delivers a message to the destination within a certain deadline (delay constraint). We propose to identify such routes based on average channel state information (CSI) only, since this information can be distributed more easily over the network. Such cases allow probabilistic QoS guarantees i.e., we maximize and report the probability of on-time delivery. We develop a convolution-free lower bound on probability of on-time arrival, and a scheme to rapidly identify a path that maximizes this bound. This analysis is motivated by a class of infinite variance subexponential distributions whose properties preclude the use of deviation bounds and convolutional schemes. The bound then forms the basis of an algorithm that finds routes that give probabilistic delay guarantees. Simulations demonstrate that the algorithm performs better than shortest-path algorithm based on statistics of path loss or CSI.