ting the average sojourn delay. However, it is also not possible to solve equation (6.26) and (6.27) explicitly for C. Therefore, for a desired delay factor f, or transfer delay T1, or throughput Dt, the optimum lub link capacity C will be derived with the iterative approach. Single RAB with CAC For a single RAB scenario, when the CAC is applied to elastic traffic, equation (6.28) and (6.29) are suggested to calculate the sojourn times. Same as above, the bandwidth C is derived from the iterative approach. Multiple RABs without Applying CAC In case of multiple RABs scenario, it is assumed that different RAB types are used by different traffic classes. For each traffic class (i.e. each RAB type), there is a different QoS requirement. The goal of dimensioning is to satisfy the QoS requirements of the individual traffic classes on an end-to-end basis. For achieving this goal, the optimum capacity C has to meet the desired QoS values of all RAB types. In section 6.3.7.3, a general form of the M/G/R-PS model is presented to calculate the mean sojourn time for each RAB type separately in the multiple RABs scenario. For dimensioning process, for each RAB type i, the general form is applied to derive an optimum capacity Ci for meeting its specific QoS requirement with the above interactive approach. At the end, in order to meet the QoS requirements of all RAB types, the maximum Ci is taken to be the optimum lub link capacity. Elastic Traffic mixed with Circuit-switched Traffic If elastic traffic is transmitted together with the circuit-switched traffic on the lub link, different approaches can be used for link dimensioning, depending on different policies for integrating elastic and circuit-switched traffic flows. The analytical model presented in section 6.3.7.5 is applied for the scenarios where both traffic types completely share the network bandwidth, i.e. the elastic traffic can fully exploit the bandwidth that is not used by the circuit-switched traffic as a result of priority scheduling. In this case, the required