as a redundant fiberoptic link for the radar data from an alter- nate service provider. However, no one knew, until too late, that the alternate service provider leased space on the same fiberoptic cable bundle under the Hudson River that held the primary service pipe. It pays to investigate the details of the plans that your service providers offer. 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 Backhaul Planning become more numerous rather than more capacious. Most communication networks grow by having small nodes get bigger, but our communication network is growing by having more and more small nodes. Our pipes, however, will grow as the fan-out back- haul network concentrates more traffic from more cells on the same transport links. When cells split, the new base stations have to send their packets somewhere, and the best place to send them is probably one of the existing base stations nearby. Thus backhaul transport pipes are likely to get bigger as well as more numerous. It is portant to anticipate growth in planning the backhaul network for the initial system. 35.7 Other Backhaul Technologies In certain areas, there may be alternative technologies for backhaul networks. In Sec. 32.5 we discussed leasing space or colocating transport facilities with cable TV net- works. Using the cable TV network would be similar to using PSTN backbone facilities, as we discussed in Sec. 35.3. Point-to-point microwave is frequently used in rural networks, especially in areas with rocky terrain that makes underground cable installation expensive. It also can be used in urban areas if there is some difficulty reaching the network. 3 In addition to in- stalling our own point-to-point microwave, we might find innovative alternatives. For example, if a company has built its own point-to-point microwave link for internal use, we might be a