partitioning; (2) bandwidth sharing. In case (1) the bandwidth reserved by the RT traffic will not be used by the NRT traffic. It can be realized by using bandwidth reservation function and rate limiting functions, which allow the partitioning of link capacity for different types of traffic. In this case, the available bandwidth for the NRT traffic is calculated by subtracting the bandwidth assigned for the RT traffic from the total link bandwidth. In case (2), it is assumed that the NRT traffic can completely share the bandwidth of the RT traffic, which is the case considered in this thesis. In this case the available bandwidth for the NRT 7 Dimensioning for Single IP-Based lub traffic is obtained by subtracting the mean traffic load of the RT traffic from the total link bandwidth. Both cases have been explained in section 6.3.9 in ATM-based UTRAN. It is assumed that there are a number of service classes (priorities) of NRT traffic, each is served by one certain RAB service and carried on one AF or BE PHB. Then the application QoS performance of each service class strongly depends on its defined priority (corresponding to the weight in WFQ), the resultant available IP bandwidth that can be used for this service class, the data rate of the RAB to transmit this service class, and offered traffic of this service class. The essential idea of the following proposed analytical approach to estimate the application performance of every service class is to apply the M/G/R-PS model per service class, but taking into account of the potential multiplexing gain of bandwidth sharing among different service classes. It can be observed from Figure 7.1 that the total available IP bandwidth for each service class contains not only the bandwidth allocated for that service class by the WFQ scheduling function according to its weight calculated with equation (3.1); but also the bandwidth that has not been utilized by all other PHBs. Because according to the theory of the WFQ scheduling, whenever one PHB does not need to use its assi