red trace traffic Figure 6.58: Measured user traffic (left) and customized BMAP (right) 6.4 Dimensioning for Transport Network Performance log(u) log(u) measured traffic linear regression linear regression Figure 6.59: R/S statistic of the measured traffic (left) and customized BMAP (right) The observations are further emphasized by the analysis of the traffic properties. Figure 6.59 presents the R/S statistics of the measured user traffic (left) and the customized BMAP (right). The degree of traffic self-similarity can be expressed by the slopes of linear regression plots of the R/S statistics. The value of H for the BMAP model is 0.68, which indicates a significant amount of traffic burstiness, compared with the Hurst parameter of the measured traffic (H = 0.69). This result also proves that when transferring the elastic IP traffic, the carried traffic of UTRAN in forms of aggregated FP PDU streams is self-similar as H > 0.5. Figure 6.60 gives another example of three Packet Switched RAB types being used at the same time, i.e. RAB 64kbps, 128kbps and 384kbps. The application is web browsing with Pareto page size distribution and an average page size of 15kbyte. The HTTP requests are equally distributed among these three RAB types. The lub link is a 2Mbps E1 line and the Permanent Virtual Circuit (PVC) on the ATM layer is set to 1.6 Mbps. Figure 6.60 compares the CDF of the FP PDU inter-arrival time obtained from the measured simulation trace and from BMAP. It is obvious that the CDF of BMAP model matches the CDF of the measured traffic very well. The average FP PDU inter-arrival time measured from the simulation is 5.8ms while from BMAP is around 5.7ms. Multiple RABs Simulations 0.005 0.015 0.025 0.035 0.045 FP PDU Inter-arrival Time (second) Figure 6.60: CDF of FP PDU Inter-arrival time - multiple RABs scenario 6 Dimensioning for Single ATM-Based lub 6.4.4.2 BMAP/D/1 If the arrival process of the AAL2 queue is modeled using the BMAP and the AAL2 buffer size is assumed to be unlimited, thus the AAL2 queue can b