dio range and to restrict their coverage. These microcell areas could be dense residential areas or heav- ily traveled commuter routes. In either case, we want to position a microcell to cover the area rather than try to find a macrocell solution that puts those subscribers in com- petition with others for CDMA resources. When the high-demand area is concentrated in a particular building or part of a building, we can use picocells. These create radio service areas confined to a radius of a few tens of meters. Large office buildings are obvious picocell targets, but train sta- tions and airport waiting areas may generate enough demand for picocells as well. 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. Planning Locations for Base Stations Planning Locations for Base Stations When there is a community of demand in an area without telephone transport, we can think about using repeaters. These are two-way reradiators with a line-of-sight path to the base station and high radio path gain to the subscriber community. We think of repeaters as a solution to be used in remote areas in countries where telephone transport is not universal as it is in the United States and Europe. The repeater might sit on a hilltop to serve people living between two mountains. Of course, repeaters re- quire electrical power, so we cannot use them in truly remote areas. Anyplace where there is a large and concentrated subscriber community is a good candidate for local equipment to serve local CDMA demand. We look at neighborhoods, office buildings, train stations, airports, or any place where we expect a lot of wireless telephone demand in one place. These are the areas where microcells and picocells can provide cost-effective service. Engineers should identify these areas in the planning process and evaluate the impact of serving the demand locally. Another opportuni