rder of the same three sec- tors, then there is some area of significant population where all three sectors have nearly the same radio path gain. Getting this information from the system means that we have to measure not only the individual handoffs but also the sequences of handoffs so that we know which groups of cells are nearly equal in radio path gain. Measuring soft-handoff activity gives us an excellent handle on the nearly equal ra- dio zones. While it appears that soft handoff reduces forward-link capacity by having multiple CDMA channels for one call, it mitigates the even greater problem of having a hard-handoff process serving the call on the wrong sector while trying to catch up. Three-way, four-way, and five-way soft handoffs are the CDMA system's way of telling us which areas are pilot-pollution zones. Once we know which cell and sector boundaries have a lot of handoff activity, we know which areas are using the CDMA carrier less efficiently than we would like. should be measuring the handoff activity levels as part of our CDMA system capacity monitoring process. 39.4.1 Soft handoff Hard handoffs are events that happen, and we can record these events. Soft handoff is an ongoing process, a call can be in a soft handoff for an extended period of time. The Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Measuring System Performance for Growth Measuring System Performance for Growth events that define soft handoff are the adds and drops of cell sectors to the soft-hand- off list. It is the soft-handoff add and drop events that we should be tracking so that we know the level of soft-handoff activity. Once we have the soft-handoff additions and deletions, we can infer the soft-handoff states in between these events. If a call starts on sector A and we see sector B added, then we have a soft handoff between A and B. When we see secto