a multi-class preemptive priority cognitive radio system with random interruption discipline
Cognitive radio system has been studied intensively. It is usually described as a multiserver queue with preemptive multiclass priority queueing system. Segal (1968) has studied a multiserver system with preemptive priority in which customers of higher priorities can preempt customers with lower priorities according to their arriving order. That is, customers with lower priorities are ejected according to the shortest time in service. In many applications, however, it is reasonable to study the system where customers of lower priorities are preempted randomly in spite of their arriving order. In this paper, we investigate such a multiserver Markovian queueing model with K priority classes with preemptive priorities and random preemptive discipline. We derive recurrence relations for the moments of the lifetime distribution of customers of lower priorities and present a numerical method of computing the solution. Finally, the moments of the lifetime distribution are compared numerically for the random interrupted system and the ordinal system.
preemptive priority cognitive radio random preemptive discipline moments lifetime distribution