n power 24 (21) (dBm) Receiver sensitivity (dBm) Interference margin (dB) Fast fade margin (dB) Antenna gain (dBi) Body loss (dB) Mobile antenna gain (dBi) Maximum path loss (dB) 153.0 155.0 154.0 In Table 7.34, we assume 2.0 dBi gain for UTRA-FDD data terminals, and 3 dB body loss for the speech terminals. The interference margin in FDD may apply to 50% load- ing. The FDD sensitivity assumes 5.0 dB BS noise figure with Eb/No = 5.0 dB for 12.2 kbps speech (AMR) and 1.5 dB for 144 kbps data. GSM sensitivity = -108 dBm. The FDD fast fade margin includes the macro diversity gain against fast fading. Co- siting assumes three-sector antenna configuration for both GSM and FDD. From the reference values in Table 7.34, we can extrapolate that the coverage of 144 kbps data service with 21 dBm mobiles may correspond to the GSM1800 speech coverage. Thus, we can provide 144 kbps data with WCDMA when re-using or co- siting GSM1800 sites with the same coverage as GSM1800 speech. In the DL we have less power restrictions; hence, higher 3G data rates may be possible with the GSM1800 coverage. On the other hand, we should be aware that coverage comparison and site GSM1800 re- utilization for WCDMA will depend on the receiver sensitivity values and other system parameters, e.g. HO, FH, power control, etc. In the following, we will expand the inter- ference levels and criteria for co-siting, as well as de-coupling issues. 7.11.1 Interference Levels and De-coupling Radio site sharing solutions implies either utilization of multi-band antennas and co- locating 2G/3G HW/SW. To assess these needs we first list the interfering levels given by the standard specifications. The UTRA FDD uses the WCDMA technology as indicated in earlier chapters. The UMTS Network and Radio Access Technology 7.11.1.1 GSM/UMTS Interference Considering the GSM recommendations (05.05 and 11.21) and the UMTS recommen- dation (25.104) outlined in Chapter 5, we can calculate the necessary decoupling be- tween: two UMTS systems; one GSM900 system and one UMTS syste