ites are usually small in number). The capacity utilisation of all other sites should be assessed. Is there a possibility to replace the leased lines with microwave radio? With microwave radio, the sites can be connected to each other (if LOS exists) and the capacity increased many times. Leased lines are usually PCM type while the microwave links are usually 2E1 to 16E1 capacity. This not only increases the spare capacity of the network, but also increases the chances of creating topologies thereby increasing the protection level. One such analysis is shown in Table 3.2. There, eight sites are analysed in a region. Each site is analysed and the topology change is proposed along with the change in the media from leased line to microwave radio. Though for some sites (e.g. site 74) there is no improvement in the capacity, the overall capacity of the system improves by over 160%. This example considers just a few sites, but when capacity optimisation takes place, minor changes in topology may lead to a tremendous improvement in capacity. TRANSMISSION NETWORK PLANNING AND OPTIMISATION Table 3.2 Example of capacity analysis Capacity Capacity Capacity S.No. Site ID Connectivity before (2 Mbps/site) Connectivity after (2 Mbit/site) improvement Optimisation (Present) Optimisation (After) 82-50; 50-06 82-50; 50-06 100.00 83-82; 30 64-83; 64-06 700.00 70-87; 70-69; 25 70-87; 70-69; 69-06 140.00 35-82; 31 35-82; 50-06 100.00 36-06 300.00 73-76; 38 73-06 166.67 74-82; 50-82; 50-06 74-82; 50-82; 50-06 Av. capacity per site (before) Av. capacity per site (after) 160.41 If new sites are to be added at the hot spots during/after the optimisation process, then the capacity increase in particular links/region should be considered apart from considering the impact of the new sites. The results of the capacity analysis should be very well understood and its effect on quality and costs analysed before making recommendation for changes in the master plan for the implementation of these recommendations. Quality Analysis Network quality