vered by the base station antenna radiations is more than the area covered by the mobile station antenna, thereby giving more coverage in the downlink direction. Reducing the power in the downlink direction can reduce this difference but results in a loss of coverage. Another way is to introduce diversity at the BTS, or even to introduce low-noise amplifiers (LNA) at the BTS. Both measures will have a positive impact on the BTS receiver power level. Another power budget calculation for GSM 900 and 1800 system using different classes of mobiles (A and D) is shown in Example 3. How can there be an improvement in the power budget results? As seen above, apart from varying the power transmitted from the BTS antenna, these results can be improved by using enhanced planning techniques such as frequency hopping and/or by using some enhancements such as receiver diversity, LNA for the uplink directions, and boosters or filters for the downlink directions. Example 3: Simple power budget calculations RADIO LINK POWER BUDGET MS CLASS RADIO LINK POWER BUDGET MS CLASS GENERAL INFO GENERAL INFO Frequency (MHz): System: Frequency (MHz): System: RECEIVING END: RECEIVING END: RX RF-input sensitivity -104.00 -100.00 RX RF-input sensitivity -104.00 -102.00 Interference degrad. margin Interference degrad. margin Cable loss + connector Cable loss + connector Rx antenna gain 18.00 Rx antenna gain 12,00 Diversity gain Isotropic power -109.00 -99.00 E=A+B+C-D Isotropic power -122.00 -97.00 F=A+B+C-D-E Field strength dB V/m 20.24 30.24 F=E+Z Field strength dB V/m 32.24 77.2 20*log(free(MHz]) 20*log(freg[MHz]) TRANSMITTING END: TRANSMITTING END: TX RF output peak power TX RF output peak power 15.85 (mean power over RF cycle) 33.00 38.00 (mean power over RF cycle) 30.00 42.00 Isolator + combiner + filter Isolator + combiner + filter RF-peak power, combiner output 33.00 26.00 M=K-L RF-peak power, combiner output 30.00 33.00 M=K-L Cable loss + connector Cable loss + connector TX-antenna gain 11.00 TX-antenna gain 18.00 Peak EIRP 28.00 Peak E