imes in data packets per second or data packets per time slot. Application Delay Jitter Application delay jitter refers to the variance of individual delay values. It is measured as the difference between the largest and smallest end-to-end delay. This QoS is mainly important for real-time traffic such as streaming audio or video. Connection Reject Ratio As introduced in section 3.3.4.3, CAC algorithms are used to decide whether an incoming connection request should be accepted or rejected in a network in order to maintain the guaranteed QoS for the end users and networks. Connection reject ratio refers to the ratio of rejected connections to the total number of requested connections in the system. It is mainly used for reservation based services. In the outline of this thesis, the user-relevant QoS is regarded as the main objective for the UMTS network dimensioning. The considered user-relevant QoS is the end-to-end application delay or throughput for the elastic traffic and connection reject ratio for the circuit-switched traffic. 4.2 Important Issues for UMTS Network Dimensioning 4.1.2.2 Network-Relevant QoS (Network Performance) For the objective of the network dimensioning and optimization problem, network- specific QoS measures are used to evaluate the quality of a network. The network-relevant QoS, measured on the packet level, is based on the aggregated traffic rather than individual flows. The most used network QoS measures are packet delay, packet loss ratio, and link utilization. End to end Packet Delay In the context of this thesis, the packet delay refers to the delay of transmitting a packet through a network domain. It contains delay components from processing, segmentation and reassembly, transmission, propagation, and queuing, etc. Packet Loss Ratio It is defined as the ratio of discarded packets to the total amount of transported packets. Within the UTRAN lub transport network, the packet discards may be caused by excessively delayed Frame Protocol (FP) PDUs that are discarded by the Node B, or 