set to 10 Mbps and the last mile link is 1 E1 (1600kbps used for the user plane). There are 2 Node Bs configured in the radio access network. In Figure 8.5, the application delay is calculated with the M/G/R-PS model that models the last mile link (with equation (6.26) and (6.27) presented in section 6.3.7.1) and compared with the measured average page transfer delay from the simulations. In the figure, the last mile link utilization is the x-axis. The left graph shows the average application delay and the right graph shows the calculated relative error of the analytical models. It can be seen from Figure 8.5 that for different load levels the average end-to-end application delays calculated from the M/G/R-PS model are quite similar to the simulation results where the relative error is below 5%. Last mile link = 1600kbps, backbone link = 10 Mbps Last mile link = 1600kbps, backbone link = 10 Mbps M/G/R-PS Simulation Last mile link utilization Last mile link utilization Figure 8.5: Delay estimations for case (1): congested last mile link and ideal backbone link Similar validation results can be obtained for case (2). Figure 8.6 shows the estimated delays from both analytical model and the simulations. In this example, there are 3 Node Bs each connected to a 3.4 Mbps last mile link (which is sufficient for the offered traffic amount on the last mile link that will not cause congestion) and the backbone link is configured with 4 Mbps. In Figure 8.6, the backbone link utilization is the x-axis. The left graph shows the average application delay and the right graph shows the relative error. The presented results validate the applicability of the proposed method for estimating the end-to-end application delay for the case (2). 8 Dimensioning for Multi-lub RAN Scenario Backbone link = 4Mbps, last mile = 3.4Mbps Backbone link = 4Mbps, last mile = 3.4Mbps M/G/R-PS Simulation backbone link utilization backbone link utilization Figure 8.6: Delay estimations for case (2): ideal last mile link and congested backbone link The a