easurements related to the busy hour, incoming traffic, outgoing traffic, etc. Knowledge in these areas aids an understanding of the condition of the system, and helps with further recommendations to alleviate prob- lems with existing and anticipated traffic. The network in general should have nomenclature consistency. The inputs for this generally consist of the naming of network elements (in the core network), the naming of destinations and sub-destinations, the naming of routes, etc. Another input required is configuration parameters of the core network elements, mainly the MSC/VLR and HLR. From the MSC/VLR, this consists of parameters related to charg- ing, roaming, authentication, ciphering, etc., while from the HLR, parameters related to transferring of subscriber data, basic and supplementary services, etc., are required. Unlike in radio and transmission network optimization, where tools other than the NMS are also used for data collection, in the core network optimisation process the NMS plays a more important role. However, the type of measurements that need to be done should be created in the switching platform. These measurements include the network elements and/or part of the system that is connected to a switch. A typical example is a control group measurement that covers all the control units in the core network, as shown in Figure 4.12. The schedule and duration of the measurements need to be specified. Planning engi- neers should take into consideration the system's capability and requirements for such measurements. Every equipment manufacturer has its own specification such as the number SWITCHING PLATFORM LONDON - 0- 1999 02:02:29 TRAFFIC MEASUREMENT REPORT SOURCE: STU 1 OUTPUT INTERVAL: 45 MIN CALLS ACCEP SFAIL IFAIL EFAIL ERLANGS LSU-0 LSU-1 CCSU-0 CCSU-1 CCSU-2 BSU-0 BSU-1 BSU-2 IWCU-O IWCU-1 END OF REPORT Figure 4.12 Example of control group measurements CORE NETWORK OPTIMISATION of measurements available, the number of measurements that can run at a given time, limita- tions on the duration