ons tell us that more capacity depends on less pilot pollution, fewer areas with multiple sectors of nearly equal radio signal path gain. We need a map that makes it visibly clear where there are areas of high pi- lot pollution and significant traffic. Areas of pilot pollution are only a capacity problem when there are subscribers using the system in those areas. Thus we want to know where the worst combination of high interference and high traffic occurs. We use our propagation models to calculate the radio signal path gain from each base station to each bin. We can use the antenna radiation patterns to figure out the path gain from each antenna face to each bin. Then, for each bin, we can rank-order the an- tenna faces in order: first, second, third, and fourth. We look at the ratio, or the differ- ence in decibels, between the first and fourth best path gains for each bin. This differ- ence is the fourth-pilot delta described in Sec. 32.1. The areas where the fourth-pilot delta is low are areas of pilot pollution, areas where CDMA capacity is compromised. These are the areas we want to see geographically on a map so that we can figure out what to do about them. The pilot delta map shows these areas superimposed on a layout of the CDMA system. When these areas are also high-traffic-density areas, we have a loss of system ca- pacity as a result. This is why we need a map that shows areas with both pilot pollu- tion and heavy call volume. It is these areas that require attention if we want to get the most capacity from our wireless telephone system. It is these areas that we want highlighted on the pilot delta map. 48.6 Measurement-Based Decisions A CDMA system analysis starts with predictive tools. The computer programs give us a preview of system performance and a diagnosis of system problems. However, the on- going operation of a CDMA system should incorporate measurements into the engi- neering process. The predictions of a computer program are no match for observing the system first- hand with measurement te