sually much less - of the order of 0.1 dB. MS and BTS antenna gain: The antennas used for MS and BTS have significantly different gain levels. For obvious reasons, the MS antenna has a lower gain, of the order of 0 dBi, while the BTS antenna gain can vary from 8 dBi to 21 dBi depending upon the type of antenna (omnidirectional versus directional) being used. This gain can be increased by using various techniques, such as antenna diversity (both uplink and downlink). Example 2: Power budget calculation Consider a BTS and MS along with the parameters as shown in Figure 2.9. RF Power of BST (UL): 42 dBm Antenna Gain (Gb): 18 dbm RF Power of MS : 32 dBm Uplink Cable Loss (UL/DL): 2 dB Antenna Gain (Gm): 0 dbm BTS Sensitivity:- 108 dBm Cable Loss (UL/DL): 0 dB Combiner Loss; 2 dB Downlink MS Sensitivity:- 106 dBm Figure 2.9 Example of a power budget Uplink calculations PLu (Path Loss in uplink) = EIRPm (Peak EIRP of Mobile) - Prb (Power Received by the base station) EIRPm = Ptm (Power transmitted from the MS) - Losses + Gm Losses = Lcm (cable loss at mobile) + Lom (any other loss) Prb = -Gb (antenna gain) - Losses + Bs (BTS sensitivity) Losses = Lcb (cable loss at BTS) + Lob (any other loss) PLu = EIRPm - Prb = [Ptm - Lcm - Lom + Gm] - -Gb + Lcb + Lob + Bs] = [32 - 0 + 0 + + 108)] = 32 + 124 = 156 dB RADIO NETWORK PLANNING AND OPTIMISATION Downlink calculations PLd (Path Loss in downlink) = EIRPb (peak EIRP of BTS) - Prm (Power received by the MS) EIRPb - Ptb (Power transmitted by BTS) + Gtb (antenna gain) - Losses Losses = Lcb (cable loss at BTS) + Lccb (combiner loss at BTS) Prm = Ms (Mobile sensitivity) + Losses - Gm (mobile antenna Gain) Losses = Lcm (cable loss) + Lom (any other loss) PLd = EIRPb - Prm = [Ptb + Gtb - Lcb - Lccb] - [Ms - Lcm - Lom - Gm] = [42 + 18 2 - 2] - 106 - 0 01 = 56 + 106 = 162 dB As can be seen, there is an obvious difference in the results of the uplink and downlink power budget calculations, where the downlink path loss exceeds the uplink power loss. This is an indication that the area co