 to compute the total required IP bandwidth for the lub link. 7.3.4 Dimensioning Results The following gives an example of applying the above dimensioning procedure to calculate the required IP bandwidth for a single lub link. Figure 7.4(a) shows the estimated IP bandwidths over different target delay factors of BE PHB (in this example BE PHB is the worst case) and compared with the simulated bandwidths. In Figure 7.4(b) the relative error is given. In this example, there is pure elastic traffic, which is carried by AF and BE PHBs. The following configurations are applied in the simulations: there are five PHBs: AF 11 (RAB 64 kbps), AF 21 (RAB 128 kbps), AF 31 (RAB 256 kbps), AF 41 (RAB 384 kbps) all NRT service classes use the same web traffic model: page size is 50 kbyte of constant distribution each Node B carries 6 elastic traffic flows per service class It can be seen from Figure 7.4 that the bandwidth requirement is reduced with a higher target delay factor (i.e. lower application QoS requirement). And through comparing the analytical results with the simulation results, it can be seen that the suggested analytical approach can give proper estimations on the required IP bandwidths (with relative error around 10%). Dimensioning of single IP lub with DiffServ QoS Dimensioning of single IP lub with DiffServ QoS M/G/R/N-PS Simulation target delay factor of BE PHB target delay factor of BE PHB (a) IP bandwidth (b) relative error Figure 7.4. Dimensioning of a single IP lub link 7 Dimensioning for Single IP-Based lub After demonstrating the analytical approach for dimensioning a single IP lub link, the analytical dimensioning approach can be used to investigate dimensioning rules. Figure 7.5 presents required normalized capacity (definition is given in section 4.3) over traffic load (in kbps) derived from the analytical approaches. Figure 7.5(a) shows the required capacity under different QoS requirements. It is seen that with a higher QoS requirement, the bandwidth demand is higher. It can be also seen that there