k utilization, the achieved delay performance is worse for the lower weight queue or service due to a less share of total bandwidth. For example, AF41 PHB has the highest weight SO its delay performance is the best whereas BE PHB experiences the most delay degradation under the congestion. 7.3 Dimensioning for Elastic Traffic AF11 PHB - NRT RAB 64kbps AF21 PHB - NRT RAB 128kbps M/G/R/N-PS M/G/R/N-PS Simulations Simulations lub link utilization lub link utilization BE PHB AF41 PHB - NRT RAB 384kbps M/G/R/N-PS M/G/R/N-PS Simulations Simulations lub link utilization lub link utilization Figure 7.2: Validation of M/G/R/N-PS Model - transfer delay Figure 7.3 presents for each PHB or RAB service the derived IP bandwidth allocated for all NRT traffic (i.e. IP_BW_NRT) using the M/G/R/N-PS model under different application delay requirements of that RAB service, and compares them against the simulation results. It shows that for all RAB services, when the delay QoS requirement is higher, i.e. the desired application delay need to be smaller, then a higher IP bandwidth is required. As explained in the above dimensioning steps in section V, if each RAB service has a specific delay requirement, then for each service we can calculate the required total IP bandwidth for all NRT traffic (i.e. B BW_NRT) under which the delay boundary of that service is satisfied, and we should take the maximum of the calculated bandwidth as the total IP bandwidth for carrying the NRT traffic (i.e. IP_BW_NRT). By comparing the simulation results and the derived IP bandwidth from the proposed model in Figure 7.3, it shows that in general the proposed analytical approach based on the M/G/R/N-PS model can give a relatively good approximation of the required IP bandwidth for the dimensioning results, SO it is proven to be a proper dimensioning approach. The presented simulation results demonstrate that the proposed analytical methods can appropriately estimate the application performances of different service classes with a DiffServ QoS framework. He