verloads at this blocking criterion, we would lower the call-blocking power threshold. And if the system is actually blocking calls and the amplifier never gets above 80 percent, then we might raise the blocking threshold to 60 percent of full power. Our time-of-day efficiency is the peak-to-average ratio, the amount of traffic demand we can serve compared with how much we could serve if our system were busy all the time. In Chap. 45 we discuss ways to improve this efficiency. 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. Base Station Planning Planning for CDMA Capacity The traffic engineering job is done when every cell sector is engineered to meet its blocking requirements for the full suite of services with time of day taken into account for the serving sector, its neighboring sectors, and its neighboring cells. 33.6 Migration from FDMA or TDMA to CDMA Conversion of existing FMDA or TDMA systems to CDMA is an opportunity to increase revenue greatly with existing radio spectrum. We wish that we could throw the switch and instantly transform the entire system and subscriber community to CDMA. How- ever, it is not that simple because there is a substantial community of legacy system users with legacy cell phones who are not going away. Thus we have to form a plan that gradually replaces the old equipment with more efficient CDMA technology. If the tran- sition is managed properly, then a dwindling legacy subscriber community continues receive good service while a new CDMA community brings in increased revenue. The specific conditions for frequency migration depend on the technology. Advanced Mobile Phone Service (AMPS), Global System for Mobility (GSM), U.S. TDMA, and SO on are different technologies and require different migration plans. Frequency migra- tion also depends, of course, on the CDMA technology being substituted. Guard-band re