load control. It is also responsible for the control mechanisms for packet scheduling and location-based services. As cellular networks mature, location-based services (LBSs) are becoming more and more important, in both 2G and 3G networks (refer to Appendix C). 8.2 TRANSMISSION NETWORK PLANNING PROCESS Fundamentally, the transmission planning process is the same as for GSM networks, but there is one important addition: the inclusion of ATM technology. The process again consists of nominal planning and detailed planning. Compared with GSM, dimensioning of a 3G transmission network is different, and in detailed planning there is ATM parameter setting to consider. All other areas are quite similar to those described for GSM transmission network planning. The process is shown in Figure 8.4. Nominal Planning Protection Dimensioning Quality Site Selection MW Plan Topology LOS Survey Equipments Detail Planning ATM Parameter 2M/TS Plan Synchronization NW Management Planning Figure 8.4 Transmission network planning process NOTE: under 3GPP Rel'99, asynchronous transfer mode is the main technology in the transmission network. Later, IP is expected to replace ATM as the main technology. A Note on Nominal Planning Nominal planning is fundamentally the same as for GSM transmission planning - protection, link budget calculations, topology, equipment dimensioning, etc. The main difference is in dimensioning of the transmission network. Owing to the presence of voice, CS data and PS data traffic, with the data consisting of both RT and NRT traffic, dimensioning becomes much more complicated. Before we venture into transmission network dimensioning, let us look at some factors that affect it. ASYNCHRONOUS TRANSFER MODE (ATM) 8.3 ASYNCHRONOUS TRANSFER MODE (ATM) B-ISDN (broadband integrated services digital network) provides digital connections capa- ble of supporting rates greater than the primary rate (i.e. >2 Mbps) between user-network interfaces. B-ISDN was developed to support business and residential customers, with constan