r HSDPA and one UBR+ VP for HSUPA. The goal of the comparisons is to find out the performance differences of the two traffic separation configurations, and discuss a more suitable configuration to apply in the UTRAN ATM transport network, which can achieve high bandwidth utilization while guaranteeing the QoS of each traffic type. Simulation Scenarios The scenario consists of one Node B and one RNC. In the simulated scenario, there are six HSPA users in the cell: 6 HSDPA in downlink and 6 HSUPA in uplink. For both HSUPA and HSDPA, an ftp traffic model is used which generates heavy traffic on both uplink and downlink. The ftp traffic model parameters are defined in Table A.6. With this ftp traffic model, all users are downloading or uploading very large files continuously. That means, all users have always data to be transmitted at any time and demanding the network resources constantly. Such a traffic model can be considered as a worst case traffic scenario from the network point of view. In addition there is a 2 Mbps Rel99 traffic transmitted on the lub as well. In this setup, the lub is heavily loaded, which is considered to be in a worst case scenario. In such overloaded traffic scenario, the investigated gain of applying traffic separation will be more significant. The simulations scenarios are classified into two Appendix categories depending on the configurations of the transport network (2 VPs or 3 VPs). The transport network is configured with a line rate of 4 Mbps. The configurations of each VP are given in Table A.7. In both scenarios, the Rel99 traffic is fully utilizing its allocated 2 Mbps capacity. File size Constant Distribution Mean file size = 5 Mbyte Inter-arrival time ~ 0.0 seconds which means immediately after the first file downloading of the second file is started Table A.6: ftp Traffic Model for HSPA 2 VPs 1 CBR VP for Rel99: PCR = 2 Mbps 1 UBR+ VP for HSDPA/HSUPA with their inband signaling traffic, PCR = 4 Mbps, MDCR = 0.4 Mbps 3 VPs 1 CBR VP for Rel99: PCR = 2 Mbps 1 UBR+ VP for HSDPA an