d dimensioning approaches will be based on analytical queuing models on the packet level to estimate the lub delay. In this thesis, two analytical models are proposed: the Markov- modulated Poisson process (MMPP) and the Batch Markovian Arrival Process (BMAP). 6 Dimensioning for Single ATM-Based lub The structure of this chapter is organized as follows. Section 6.4.1 presents the lub system model on the packet level. Section 6.4.2 analyzes the characteristics of the aggregated traffic on the lub. Section 6.4.3 presents the analytical dimensioning models based on MMPP, and section 6.4.4 presents the dimensioning method with BMAP. Both analytical models are used for building queuing models to analytically approximate the aggregated traffic on the lub and estimate the resultant lub transport delays. In both sections, it is explained in detail how apply these queuing models in the dimensioning framework, the required procedure for estimating the necessary lub bandwidth for satisfying certain lub delay performance and finally validate them through simulations. 6.4.1 System Models for the Iub Interface This section is intended to analyze the system models of the lub interface on the packet level, in order to set up appropriate analytical queuing models for estimating the overall lub transport delays and in turn to dimension the lub link properly. To understand the system models, it is necessary to analyze the delay over the lub interface, including its components and their relations to the given lub link capacity. With the detailed lub delay analysis, the generic system models can be proposed for setting up queuing models for calculating the lub transport delay. 6.4.1.1 Delay Analysis on the Iub In UMTS, each Node B serves a number of mobile users in the cell with each of the users generating different traffic streams related to different applications. The traffic from all users served by the same base station is aggregated and then transported over the lub link. As seen in Figure 6.42, each user traffic stream (voice,