ic denoted as Pelastic can be derived by: Pelasic (6.38) Assuming that all elastic traffic flows use the same RAB type and thus with the same peak rate rpeak , the average application performance of elastic traffic in this case will be still 6.3 Dimensioning for Elastic Traffic derived from the M/G/R-PS model, but R is calculated with R = Celastic Thus the expected delay of transferring an amount of data of size x can be derived from equation (6.26) and (6.27), given the calculated normalized elastic traffic Pelastic and an estimated RTT elastic traffic which is obtained under the low link utilization. With this approach, the bandwidth sharing between the two traffic types and their dependency as a consequence of strict priority scheduling are modeled by considering the long time average impact on the elastic flow performances. This will be sufficient for the purpose of dimensioning, which is based on a long time observation. The thorough impact of priority queuing at the network level will be modeled with exact queuing model, which will be described in chapter 6.4. 6.3.8 Validation of Extensions of Processor Sharing Models This section demonstrates the applicability of the proposed Processor Sharing (PS) models and validates the above proposed extensions for the TCP-based elastic traffic for a desired application QoS. For validations, extensive simulations were carried out and then they were compared with the theoretic expectations from the PS models. The criterion for the application of the PS models is an accurate estimation of the average transfer time over the transferred amount of data. In the following sections validation results are presented. The results demonstrate that the proposed several extensions on the PS models are applicable for the objective of the lub dimensioning for different network and traffic configurations. 6.3.8.1 Simulation Environment The simulations were carried out with the developed the ATM-based UMTS Rel99 simulation model, which is introduced in Chapter 5.4. The network scenario 