At the end, to summarize the proposed analytical dimensioning approaches in this work a dimensioning tool is implemented in this thesis containing all proposed analytical models. The developed dimensioning tool can be used by network operators to perform dimensioning of various traffic scenarios, UMTS radio access networks, transport solutions, QoS mechanisms and network topologies. Overall, all investigations and analytical dimensioning models presented in this thesis help network service providers to optimize their network infrastructure to reduce the transport costs while still can provide the desired quality of service to the users. 9 Conclusion and Outlook Outlook The analytical models and approaches proposed in this thesis can serve as a basis for further researches in the area of access network dimensioning. One of the most present radio access network technology, the Long Term Evolution (LTE) as introduced in section 2.3.5, has addressed a potentially much higher demand on the transport bandwidth in the access network than UMTS Rel99, HSDPA and HSUPA networks. Thus, to derive new dimensioning approaches for the LTE network to consider future traffic and network scenarios are now an important task. It would be an interesting topic to investigate if the current applied traffic models and dimensioning models are still applicable for the future mobile networks such as a LTE network. Appendix A.1 ATM Cell Format The format of the ATM Cell is given in Figure A.1 for User-Network Interface (UNI). GFC: Generic Flow Control (4 bits) VPI : Virtual Path Identifier (8 bits UNI) or (12 bits NNI) VCI: Virtual channel identifier (16 bits) Payload Type (3 bits) CLP: Cell Loss Priority (1 bit) 48 bytes of payload HEC: Header Error Correction ATM Cell Figure A.1: Format of the ATM Cell A.2 AAL2 Packet Formats The format of the CPS packet is shown in Figure A.2 [Mcl97]. CPS-Info (1...45/64 octets) 3 octets CPS-Packet header CPS-Packet payload (CPS-PH) (CPS-PP) AAL2 Packet Figure A.2: Format of the AAL2 CPS Packet X. Li, Rad