Radio Network Optimisation Effect on DAP Transmission Network Optimisation Final Radio Network Optimisation Plan Figure 6.7 Radio network optimisation in EDGE network networks. Transmission network optimisation remains similar also, except for optimising the Abis capacity SO that it does not become a bottleneck for the air-interface. 6.4.1 Radio Network Optimisation Coverage, capacity and quality can be improved by using the standard principles of opti- misation that have been described earlier for GSM/GPRS The main focus in EDGE radio network optimisation will be on throughput, which affects the capacity and coverage di- rectly. One important point to remember is that, since EDGE implementation will generally be on top of an existing GPRS network, it is essential that throughput improvement is measured and analysed with respect to that of the GPRS network. 6.4.2 Transmission Network Optimisation The optimisation process is similar to that in GSM networks, however, there are two extra factors that need to be considered during the EDGE optimisation process: the dynamic nature of the Abis interface, and the air-interface throughput changes due to the bottleneck created by the Abis. As there is a pool of time slots reserved for packet data, it will always be the case that the number of packet service users increases in the network. Though the pool itself will be dynamic, the number of time slots that will be used for the pool will be static; SO once it is figured out that the required time slots (in the pool) need to be increased, some optimisation will be required. The situation is more severe if the number of PCMs required per base station also needs to be increased. Key Performance Indicators The major extra KPIs relate to the definitions of the EDGE territory, BLER (block error rate), MCS schemes used, BCCH usage, etc. These parameter settings define the initial NETWORK OPTIMISATION throughput. Adjustments to these settings (apart from those in the GSM/GPRS network) will permit maximisation of throughput. Perfor