ffic in picocells where user terminals are near their base stations. These data ser- vices can be circuit-switched or packet-based. There is a wide range of circuit-switched data rates: 32- to 64-kbps computer connections analogous to dial-up modem connections Integrated Services Digital Network (ISDN) access up to 144 kbps 64- to 384-kbps connections for videoconferencing Packet services are looking even brighter. Plans include multimedia and other data ser- vices to a public packet data network (PPDN) such as the Internet with peak rates ranging from 64 kbps to 2 Mbps. This includes Internet Protocol (IP) packet-based videoconferencing. Traffic data services are carried in RLP. 7We wanted to call them substandards, but they may not be substandard. 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. Worldwide CDMA Standards Standards for Cellular Systems TABLE 10.2 cdma2000 Bandwidth Bandwidth Suffix 1.25 MHz 3.75 MHz 7.5 MHz 11.25 MHz 15.0 MHz 10.2.2 cdma2000 speech coding The speech coding standards for cdma2000 are the two optional codecs from cdmaOne, the 8.55-kbps EVRC codec using RS1 and the 13-kbps codec using RS2. 10.2.3 cdma2000 radio bandwidth The radio spectrum of cdma2000 is based on the cdmaOne FDD 1.25-MHz channel as its quantum level of radio spectrum. The cdma2000 standard offers five bandwidths each direction, as shown in Table 10.2 with their multiplier suffixes. Add an extra 1.25 MHz for guard bands in each direction, and double these bandwidth figures for a full two-way FDD system, so a 3x system uses 10 MHz of radio spectrum. There is more flexibility than just a selection of five bandwidth choices, however. First, the wireless service provider may elect to use different bandwidths for forward and reverse. For a community that surfs the World Wide Web, a 3x forward link and a 1x reverse link may be ideal. Second, the bands 