very 8.4 Dimensioning for Elastic Traffic in IP-Based UTRAN service class on that link. If there are additional IP bandwidths reserved for Real Time (RT) traffic or signaling traffic, then these extra reserved bandwidths need to be added as well for the dimensioning of the total link capacity. At the end, the calculated dimensioned capacity for the ith last mile link is denoted as Cac_i and the one for the backbone link is represented by Cbb. per service class k Pk(1) K Service Classes peak k PS Model extended for IP DiffServ QoS Cac_1 Last mile link 1 per service class k fac_k K Service Classes peak_k PS Model extended per service class k Nk(i) for IP DiffServ QoS Pk (n) K Service Classes Backbone Link rpeak_k PS Model extended Nk(n) for IP DiffServ QoS Cac_n Last mile link n fac_k Figure 8.13: Dimensioning for elastic traffic in a multi-lub IP RAN with K service classes using DiffServ QoS Structure 8.4.2 Dimensioning Results This section presents the dimensioning results, which are derived from the proposed analytical dimensioning approach presented in the last section 8.4.1. And they are validated by simulations. The applied simulation model is the simplified IP-based UTRAN model (see section 5.5.2). In the following presented dimensioning examples, the simulation scenarios consist of five NRT service classes each carried by one AF or BE PHB. Table 8.2 characterizes these five NRT service classes and their mapping to the DiffServ PHBs. The configurations of Weighted Random Early Detection (WRED) function and WFQ parameters for each AF and BE PHB are given in Table 8.3. In addition, the following configurations are applied in the simulations. 8 Dimensioning for Multi-lub RAN Scenario there are 4 Node Bs in the RAN, structured as a star topology network architecture. each Node B transports the five NRT service classes concurrently using the defined DiffServ QoS functions. Each Node B has the same traffic demand, and the total amount of traffic transmitted on each last mile link is around 1.25 Mbps in average. al