Computing the blocking probability in tactical communications networks

Tactical communications networks are multi-hop wireless networks in which switches and endpoints are mobile nodes. In a tactical environment, fast algorithms for performance analysis are desirable for optimizing the network in a timely fashion. Also, preemptive priorities are commonly used to achieve low blocking probabilities for high priority calls when the loss of equipment in the battlefield is not trivial. Analytical algorithms are presented for computing the end-to-end blocking probability in a tactical communications network where a preemption service discipline is employed and traffic is divided into multiple classes to provide multiple grades of service. Each class of traffic has its distinct characteristics, such as average call arrival rate, average call holding time and service priority. Experiments show that the preemption does provide significantly better performance for higher priority traffic. The algorithms presented may also be useful in the optimization of other rapidly deployable networks, where mobility, communication efficiency and computational complexity for adapting the network to unpredictable environments are of significant concern.