Blocking Probability Estimation for Trunk Reservation Networks

In this paper, we consider the problem of estimating steady-state blocking probability for circuit-switched networks with alternate routing. In particular, we focus on networks protected by trunk reservation. A new blocking probability estimate, the so-called overflow priority classification approximation (OPCA), is considered as an alternative to the currently used the Erlang fixed-point approximation (EFPA). OPCA is applied to the case of arbitrary circuit-switched networks with trunk reservation. We show through empirical results that OPCA yields a superior estimate for blocking probability compared to EFPA for circuit-switched networks with alternate routing that are reasonably protected against instability by trunk reservation.