Efficient Routing of Mobile Agents in a Stochastic Network

Mobile agents are autonomous programs that may be dispatched through computer networks. Using a mobile agent is a potentially efficient method to perform transactions and retrieve information in networks. Unknown congestion in a network causes uncertainty in the routing times of mobile agents so the routing of mobile agents cannot rely solely on the average travel time. In this paper we deal with a given stochastic network in which the mobile agent routing time is a random variable. Given pre-specified values R and PR, the objective is to find the path with the minimum expected time under the constraint that the probability that the path time is less than R is at least PR. We show that this problem is NP-hard, and construct an exact pseudo-polynomial algorithm and an ε-approximation algorithm (FPTAS) for the problem.