city, we might be smug about the coverage problems of initial sys- tem configurations. It is the ability to add subscribers to an existing system at mini- mum cost that excites the growth planner. Getting the wireless telephone radio signal to the millionaires in Sweetwood Canyon is something they better do right in early de- ployment because those people are the corporate executives who decide which wireless carriers are getting the big contracts. However, before we get too comfortable, as students of CDMA capacity, we have a few issues and challenges of our own. The conventional-reuse channel sets with their distant cochannel interferers protect us from the immediate threat of interference from neigh- boring cells and sectors. In a CDMA call, about half the interference comes from same- sector calls, and about half comes from immediate neighboring sectors and cells. We are being a bit loose here because "about half" could be anywhere from one-quarter to three- quarters, but the important point is that little interference is coming from anywhere else. A large area of nearly equal radio signal path gain to four or more cell sectors is a CDMA capacity nightmare. Thus our conventional-reuse friends can relax while we worry about the intricacies of the radio environment at cell boundaries that concern them far less. 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. Propagation Models Modeling for CDMA In conventional reuse, capacity planning is an issue for mature systems with a lot of cells. During the early stages, there are plenty of radio channels to spread around the few cells being constructed. The distinction between coverage and capacity engineering is not so clear-cut in CDMA. Weak signal paths in CDMA lead not always to poor calls but often to low capacity. The link budget of a CDMA carrier that could carry 60 calls under ideal circumst