a method of obtaining optimum rf performance for a slave base station when co - siting a master base station with said slave base station involves calculating operating characteristics of the slave base station that is sharing an antenna assembly with the master base station . the third order intercept and the noise figure characteristics of the slave base station are calculated and plotted versus a range of upfront gain values . the plots are studied and compared against vendor specifications and standalone performance characteristics . a desired upfront gain value is then selected to achieve a particular ip3 and nf characteristic for the slave base station . upon selection , the upfront gain supplied to the slave base station is adjusted via an attenuator placed in - line before the slave base station to match the desired upfront gain .