The erlang multirate loss model under the threshold and Bandwidth Reservation policies

We consider a multirate loss model of a link that accommodates Poisson calls. Calls compete for the available link bandwidth under the combination of the Threshold (TH) and the Bandwidth Reservation (BR) policies. The TH policy limits calls of each service-class up to a threshold, which can be different for each service-class. The BR policy reserves part of the available link bandwidth to benefit calls of high bandwidth requirements. In the proposed model, the calculation of call blocking probabilities and link utilization is based on approximate, recursive formulas whose accuracy is verified through simulation and found to be quite satisfactory.