Engset multi-rate state-dependent loss models with QoS guarantee

We consider a single link loss system of quasi-random input, described by the Engset multirate loss model (EnMLM). Blocked calls may once reattempt to be connected to the system requiring less bandwidth; then the system is described by the single retry model for finite sources (f-SRM). The EnMLM and the f-SRM are extended with the single threshold finite source model (f-STM), where calls may attempt to be connected to the system with less bandwidth requirements, according to the link occupancy, before blocking occurs. We focus on CBP equalization in the EnMLM, f-SRM and f-STM, under the bandwidth reservation (BR) policy. For this analysis, we apply two approximate methods, the Roberts’ method and the method of reverse transition rates (RTR), which lead to a recursive CBP calculation. We evaluate the accuracy of the above models under the BR policy by comparing the analytical with simulation CBP results, based on the relative approximation errors (RAE). The results are highly satisfactory because they show that the proposed models (formulas) lead to small RAE. Copyright # 2005 John Wiley & Sons, Ltd.