on over the lub link, and thus, to avoid instability and low throughput in case of traffic overload (e.g. during busy hours). It is assumed that each elastic flow (i.e. TCP flow) corresponds to one connection on the lub. In the context of this thesis, the admission control for elastic traffic in the UTRAN is based on limiting the maximum number of simultaneous connections transported over the lub link. It has been mentioned by Roberts et al. in [MR99] that when a per-flow access control is applied in the system a blocking model needs to be used to estimate the related QoS. Thus for a correct dimensioning model, the previous M/G/R-PS method has to be extended to have the limitation of a maximum number of N active connections allowed simultaneously sharing the common resources. For this purpose, the M/G/R/N-PS model is suggested in this thesis by introducing 6.3 Dimensioning for Elastic Traffic an additional parameter N into the M/G/R-PS model, where N indicates the maximum number of allowed connections. In the considered CAC scenario, it is still assumed that all UEs have the same RAB type, i.e. with the same peak rate peak Additionally, they all request the same CAC guaranteed bit rate (see section 3.3.4.3), which is denoted as rm. It is defined as bandwidth requested by a connection for meeting its QoS, which also implies the minimum bandwidth this connection can get. Given the link capacity C, the link is thus modeled as M/G/R/N-PS model with R = C/rpeak and maximum number of allowed flows N = C/rm. The calculation for the M/G/R/N- PS model can be derived directly from the M/G/R/oo-PS model, only that the state space corresponding to the number of flows or connections is now restricted to a total of number of N. The state probability of the M/G/R/N-PS model is calculated in equation (6.28). (j<R) -E,(R,Rp)pN-R, (6.28) E2(R,Rp)p+-1-p) 1-E(R,Rp)px-p In the above equation P denotes the offered load (or link utilization). With the state probability, the average number of connections E{W} can be calculated. By apply