 6.2 RNP + TNP Dimensioning output Data Traffic in the BH Kbit/s per cell Acceptable avergage user Kbit/s throughput RTSL per mobile Timeslot Capacity Kbit/s PS Traffic intensity Data Erlangs Number of RTSL per cell Utilization Tps / Ns Reduction Factor Calculated f (Nu = 2, Ns = 4, Utilisation) by RF Avg user throughput (without RF*Nu*k transmission limitations) EDAP pool size Abis data rate reduction factor AbisRF Calculated 0.9962 by TRS Avg user throughput (with Abis Trg * AbisRF 71.728 transmission limitations) 6.3.5 Core Network Planning Both CS and PS core network planning remain similar to what was described in Chapters 4 and 5. The major change in the packet core section is enhanced capacities of the BSC and SGSN to cater to higher data rates on the radio network. Dimensioning of the packet core network mainly involves the PCU, the Gb interface and the SGSN, as follows: PCU dimensioning: Number of transceivers that can be supported by one PCU Amount of (data) traffic that can be handled by one PCU Number of traffic channels that can be handled by one PCU Gb interface dimensioning: Minimum number of Gb interfaces required between the PCU and SGSN Uplink and downlink traffic calculations for the frame relay links SGSN dimensioning: Number of subscribers Processing capacity of the SGSN Gb interface capacity. 6.4 NETWORK OPTIMISATION Optimization of an EDGE network will focus mainly on the radio and transmission networks owing to the increased data rate on the air-interface and the introduction of the dynamic Abis feature on the Abis interface. Usually, optimisation of radio and transmission networks is performed separately, but this scenario changes owing to the fact that the dynamic Abis pool, if not properly planned, may become a bottleneck for the air interface throughput. There are three main steps, as shown in Figure 6.7. The 'conventional' radio network op- timisation process will be quite similar to that explained in earlier chapters for GSM/GPRS EDGE: NETWORK PLANNING AND OPTIMISATION 'Conventional 