affic determines the MSC server dimensioning. Packet switched traffic is controlled by the GSN servers and does not impact the MSC server. The MSC server capacity is influenced by the number of call attempts for circuit switched services and by the total circuit switched Erlangs in the network. Assuming co-located MSC/VLR/HLR/AuC and signalling functionality in one physical node, Table 7.26 illustrates 3G MSC/HLR locations. The software on the MSC servers is dimensioned according to the simultaneous call capacity (SCC). The SCC equals the CS total traffic (in Erlang). Table 7.26 Number of 3G MSC/HLR 2002 and 2005 Location MSC/VLR SW for SCC for Signalling Projected HLR HLR/AuC CS (Erlang) HW/SW, e.g. capacity (x103 2Mb boards subscribers) City A 9375.7 City B 6250.5 City C 5208.75 Total 15580 20835.0 Deploying 3G Networks TRANSMISSION NETWORK ASSESSMENT To adapt or implement a new transmission system for 3G networks implies taking into account existing factors into the new factors such as wider band applications and larger base of subscribers, as well as existing 2G traffic if any. In the following, before illus- trating the dimensioning of a transmission network for our field study we outline some of the major issues that concern building a 3G transmission network. 7.10.1 Building 3G Transport Systems Some of the factors which will have non-negligible impact on the design of a 3G trans- mission network include: new services with higher average traffic per subscriber, which will increase the traffic density in urban areas, the latter resulting in a denser BS net- work, new dedicated sites, new transport links. In addition, service evolution will also play an important role because a large number of 3G networks will also continue to serve 2G subscribers. These subscribers will continue utilizing evolving applications such as: SMS, emails, ftp, Internet, interactive games, video calls, WAP, e-commerce, and video telephony, etc. Due to the increase in multimedia applications, traffic can easily increase from today's