ble to colocate base stations on their towers and lease space on their mi- crowave pipe at low cost. One service that has been defined and prototyped but not fully deployed is worth mentioning as a possible backhaul alternative. It is the multichannel multipoint dis- tribution system (MMDS), which is designed to function as a high-capacity radio net- work operating on a cellular model. It can offer digital television and high-speed data services. Cells have a radius of up to 35 miles. Where MMDS exists, it might be possi- ble to use it as backhaul for one or more base stations. MMDS deployment has run into financial difficulty, so in cities where prototypes exist the owners of the prototype sys- tems might welcome the revenue they would receive by providing backhaul for cellular telephone networks. 35.8 Conclusion Following the steps in this chapter, it should be possible to develop a reliable, cost- effective backhaul network that provides sufficient capacity to support all the voice and data services through each base station of our cellular system. We now turn our tention to planning our networks so that they have sufficient capacity to support signaling. 3 One of us (Kemp) worked for a university that used microwave transmission to deliver cable TV programs to the TV studio for broadcast but was unable to receive cable TV in the same build- ing for a number of years. This was in central Manhattan, where it cost over $1 million to lay a pipe with cable across a small crosstown street. 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. Backhaul Planning 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. Source: CDMA CAPACITY AND QUALITY OPTIMIZATION Chapter Signaling Capaci