mensioning in order to satisfy a desired application QoS or a desired reject ratio. 6.3.8.4 Multiple RABs without Applying CAC This section demonstrates the general M/G/R-PS model presented in section 6.3.7.3 for multiple RABs scenarios where no admission control is applied in the UTRAN. In the following validation scenarios, constant file size distribution is used. At first, an ftp scenario is given which mixes three user groups each with a different RAB type: 64 kbps, 128 kbps and 384 kbps, to transfer a 12 kbyte file. The ftp requests are equally distributed among the three user groups (each 33.3%). Figure 6.30 plots the simulated average file transfer delays of individual user groups corresponding to different RAB type and compares them with the analytical results calculated for each RAB type separately using formula (6.31) to (6.34). The load in the graph corresponds to the total file requests of all user groups (calculated with equation (6.31)), which is represented as a normalized total load or link utilization. 6 Dimensioning for Single ATM-Based lub Constant File Size 12kbyte M/G/R-PS (RAB 128) Simulation (RAB 128) M/G/R-PS (RAB 64) Simulation (RAB 64) M/G/R-PS (RAB 384) Simulation (RAB 384) Figure 6.30: Average application delay over the load for multiple RABs: ftp scenario, no CAC, constant file size (12kkyte) It is seen in Figure 6.30 that the calculated average transfer delay for each individual RAB type is close to the simulation results obtained from the simulations. This means, the general form of the M/G/R-PS model can be applied well to estimate the application performance of each RAB type in a multiple RABs scenario. The results also prove that there is a quasi fair sharing of the available resources among different TCP flows with various RAB types. The load contributed by all RAB types (user groups) is counted for the delay factor of each RAB type, though the parameter R of certain RAB type i in the individual M/G/R-PS model is calculated with equation (6.30). However, it is also obvious to se