 network elements are used to handling TDMA traffic and work with an assumption that traffic received is synchronous, which is not true for the 8.6.6 Network Management Plan The last step in the design of the transmission network is the management plan. This will consist of management of communications of the DCN (data communication network) which will use the next hierarchal layer over the ATM, i.e. the IP layer. The plan will also have information about management of the transmission equipment, such as PDH radio and SDH equipment. While doing DCN planning, the designer has to take into consideration many aspects, mainly the capacity of the Iub interface. The capacity of the Iub interface may range from 32 kbps to 128 kbps. Another aspect is the topology. The same topologies that are used in the network design can be used for DCN planning, including tree or chain topologies. The connections can be based on IP-over-ATM or pure IP. In either case, the IP addressing has to be such that there is always scope for future expansions, both in terms of network elements and technology. In a few years, fourth-generation technologies will have arrived, which are IP-based networks. Of course, equipment limitations have also to be taken into consideration when planning the IP addressing. TRANSMISSION NETWORK OPTIMISATION 8.7 TRANSMISSION NETWORK OPTIMISATION 8.7.1 Basics of Transmission Network Optimisation The transmission network optimisation process is fundamentally the same as for GSM transmission networks, but there are two additional considerations: parameter setting and quality of service. The process starts with defining the key performance indicators (KPIs) and the data collection process, followed by analysis of this collected data in terms of capacity, quality and parameter settings. The final optimisation plans are then made to meet the desired quality of service (see Figure 8.14). Process Definition Definition of Key Performance Indicators Data Collection Network Analysis Network Capacity Analysis RT/NRT Network 