re are 10000 subscribers each in the dense urban, urban, sub-urban and rural types of area. Each region has 50 base stations and each site has a configuration of 1 + 1 + 1. SHO = 40%. VAF = 67%. Total CS voice = 20mErl per subscriber. Total CS data (64 kbps) = 1.50 mErl per subscriber. Total PS data 64 kbps) = 0.012 kbps per subscriber. Total PS data (128kkps) = 0.272 kbps per subscriber. Total PS data (384 kbps) = 0.06 kbps per subscriber. Total lubtraffic = CS (voice + data) traffic + PS traffic + signalling + overheads + O&M. Assuming that the ATM overheads are 30%, signalling overheads in both the RAN and CN are 10% each, and the packet data overhead (GTP, IP, etc.) is 20%, the results are shown in Figure 8.9. Total traffic to Total Total Total lub Sites Total Voice CS Da ta PS Da ta traffic/site per si te (Mbps) BS Type (kbps ) (kbps) (kbps) (kbps) (kbps) Phase 1 D Urban 10000 1+1+1 178.3 349.4 527.70 Urban 10000 1+1+1 178.3 349.4 474.0 1001.70 Suburban 10000 1+1+1 178.3 349.4 474.0 1001.70 Rural 10000 1+1+1 178.3 349.4 474.0 1001.70 lu to MSC lu to SGSN No of BS Type #Sites (BS) CSMbps PSMbps RNC MSC RNC .> SGSN RNC- RNC Phase 1 D Urban 10000 1+1+1 12.89 Urban 10000 1+1+1 12.89 Suburban 10000 1+1+1 12.89 Rural 10000 1+1+1 12.89 40000 21.74 51.57 Figure 8.9 Example showing the results of transmission interface dimensioning 8.5 MICROWAVE LINK PLANNING Microwave link planning is similar to that for GSM transmission planning. However, in 3G networks, ATM over microwave links seems to generate a concern over the quality of the links. MICROWAVE LINK PLANNING 8.5.1 Error Rate and ATM Performance In GSM transmission, a BER of 10-3 is considered to be good enough to meet the desired quality, but GSM transmission links carry more voice traffic than data. In 3G networks, with the traffic scenario changing (i.e. more data relative to voice), new standards are required for transmission systems. Moreover, networks in 3G are ATM-based. The main difference in microwave planning between GSM and 3G is the BER threshold consi