ed to be connected to the BSC. When the deadlines are fast approaching, the usual way to connect these sites is through leased lines, SO topology TRANSMISSION NETWORK OPTIMISATION Process Definition Definition of Key Performance Indicators Data Collection Network Analysis Network Capacity Analysis Network Quality Analysis Master Plan (Optimisation Proposal) Figure 3.26 Cellular transmission network optimisation process design, its effects and benefits may be neglected. Temporary solutions may result in under- utilisation of the media that is connecting the sites. Another major factor is congestion in the network that may be due to the increase in the number of mobile users. This may lead to an increase in the number of TRXs at each site, thereby forcing the transmission planning engineers to come up with solutions to cater for the traffic increase without increasing the number of base stations. Another reason could be the need to upgrade the network technologically, e.g. 2G to 2.5G or 3G. The capacity optimisation process ends up with a twofold solution. It provides answers as to how to use the existing capacity effectively, and how to increase the capacity with minimal disturbance to the network functionality and revenue inflow. Apart from this, the network will be more flexible and reliable. How should capacity analysis be done? Engineers first collect regional data. Apart from having site information (site location, coordinates, height, etc.), information collected should include site capacity (present as well as forecasted), 2 Mbps routing plans, and media information (e.g. leased line, microwave radios, optical cables, etc.). Coverage plans will also help if new sites are being introduced. From this information, transmission planning engineers should calculate the existing and forecast capacity of each link. The next step is to identify the media. Base stations that have no line-of-site (LOS) to another base station or BSC might be using leased lines/optical cable to get directly connected to the BSC (such s