E. Gregori et al. (Eds.): NETWORKING 2002, LNCS 2345, pp. 660-671, 2002. © Springer-Verlag Berlin Heidelberg 2002 An Optimal Reservation-Pool Approach for Guaranteeing the Call-Level QoS in Next-Generation Wireless Networks Fei Hu and Neeraj K. Sharma Department of Electrical & Computer Engineering, Clarkson University P. O. Box 5722, Potsdam, New York 13699-5722, USA {Huf, sharman}@clarkson.edu Abstract. In order to provide the guaranteed mobile QoS (Quality-of-service) for arriving multi-class calls, we need to minimize the dropping rate of handoff calls while at the same time controlling the blocking rate of new calls. This pa- per proposed a new multi-class call admission control mechanism that is based on dynamically formed reservation pool for handoff requests. The simulation re- sults show that the individual QoS criteria of multi-class traffic such as the handoff call dropping probability can be achieved within a targeted objective and the new call blocking probability is constrained to be below a given level. The proposed scheme is applicable to channel allocation of multi-class calls over high-speed multimedia wireless networks. 1 Introduction Multimedia mobile communications are expected to be the dominant mode of access technology. Besides traditional voice communication, a new range of services such as multimedia, high-speed data, etc. are being offered for delivery over wireless net- works. Mobility will be seamless for implementing the blueprint of person’s being in contact anywhere and at any time [1-3]. Mobile Quality-of-Service (M-QoS) is a set of performance parameters associated with wireless link such as channel error rate and with mobile units such as Handoff-call Dropping Probability (HDP) and New-call Blocking Probability (NBP). In order to provide higher capacity on the limited radio spectrum, we should use smaller-sized cells such as pico- cells instead of macro- or micro- cells. For such a small cell size, handoff will occur more frequently and make HDP a crucial consideration in M-QoS. Such handoffs involve allocating sufficient resources in each arriving cell to maintain the QoS needs of the established connec- tions. It is a common practice to give a higher priority to the handoff calls as com- pared to new calls. On the other hand, giving too much priority to handoff calls will result in an excessive NBP. Denying of too many new calls can bring an unacceptable ratio of carried-to-admitted traffic and a unsatisfactory revenue for network providers. Various channel allocation schemes have been proposed to implement handoff priori- tization and at the same time not hamper the acceptance of new calls.