ons as gi- ant cells. Just as the service area is divided into cells, base stations are divided into MSC regions. In the CDMA air interface, the borders between cells are the problem ar- eas from both a capacity and a communication perspective. In the same way, the bor- ders between MSC regions are the problem areas for inter-MSC communications. We want to assign base stations to MSCs so that the MSC giant cells have little in- teraction, less demand for inter-MSC handoffs and inter-MSC handoff requests, which are generated when the signal strength is close to equal at base stations served by dif- ferent MSCs. Calls from inter-MSC border areas will have inter-MSC handoffs. If the border area involves three or four MSCs, then inter-MSC handoffs become more com- plicated. Those are the areas where the ANSI-41 signaling system uses all the compli- cated messages in Sec. 15.1. This means that we want to keep inter-MSC borders away from busy areas. Like reg- ular cells, the giant cells of MSC regions have to have borders, and somewhere, they have to have triple-points. Thus one goal of base station assignment is to ensure that those MSC triple-points are areas with low wireless telephone demand, and another is to have few zones involving four or more MSCs and to place those in areas of low de- mand as well. If the giant cells have borders in high-traffic areas, then we may need to change assignment of base stations to MSC SO that the borders are in low-traffic areas. We may 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. Mobile Switching Center (MSC) Planning Mobile Switching Center (MSC) Planning have to do some base station assignment gerrymandering.' There are inter-MSC com- munication and confusion issues during call setup as well as handoffs. The job of assigning base stations to MSCs is done when the base stations generate an even workload 