of the data with the available share capacity. It shall be noticed that the approximation for the expected transfer time is dependent on the given object sizes. 6.3 Dimensioning for Elastic Traffic If the object size x is larger than Xslow-start, the transfer will take n* time steps to reach the state of start utilizing the available bandwidth and further transfer the rest of the data, i.e. (x - Xslow-start), with the shared available capacity. If the object size x is smaller than Xslow-start, the sender can never reach the state of fair capacity sharing, instead all packets are sent out during the slow start phase. Then the transfer takes round trip times waiting for the acknowledgements, during which the amount of data being transferred is denoted as Xstart: (6.25) Thus (x - Xstart) gives the amount of remaining data according to the last acknowledgement, which is sent using the available capacity. In equation (6.24), EM/G/R {T(x)} is the sojourn time using the basic M/G/R-PS model according to (6.18). By comparing (6.24) with (6.18), it turns out that the linear relationship between object size x and the expected transfer time disappears when TCP flow control is taken into account. Thus object size distributions with a substantial probability of files mainly driven by slow start phase perceive higher average delays than derived from consideration of mere object size and delay factor. It has to be noted that the system utilization remains the same, i.e. the impact is restricted to the performance experienced by individual flows. 6.3.7 Suggested Extensions on M/G/R-PS Model for Iub Dimensioning For the objective of lub dimensioning for elastic traffic, based on the basic and extended M/G/R-PS models introduced above in section 6.3.5 and 6.3.6, several extensions are suggested in this thesis on the M/G/R-PS model to consider the specifics of UMTS including related resource and traffic management functions such as CAC and BRA (see Chapter 3). The following sections (section 6.3.7.1-6.3.7.5) present in detail these