rated Services Data Network (ISDN) rates up to 64 Kbps. The next phase of cdmaOne is a standard known as 1XRTT and enables 144-Kbps packet data in a mobile environment. Other features available include a twofold increase in both standby and talk time on the handset. All of these capabilities will be available in an existing cdmaOne 1.25-MHz channel. The next phase of cdmaOne evolution will incorporate the capabilities of 1XRTT, support all channel sizes (5 MHz, 10 MHz, and SO on), provide circuit and packet data rates up to 2 Mbps, incorporate advanced multimedia capabilities, and include a framework for advanced 3G voice services and vocoders, including voice over packet and circuit data. Many of the steps have already been started and put in place. Table 11-2 summarizes the variations of CDMA. 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. Future Enhancements and Services Future Enhancements and Services Table 11-2 CDMA Type Description The Various Forms of CDMA Composite CDMA/TDMA Wireless technology that uses both CDMA and TDMA. For large-cell licensed band and small-cell unlicensed band applications. Uses CDMA between cells and TDMA within cells. In addition to the original Qualcomm-invented Narrow- band CDMA (N-CDMA) (originally just CDMA) also known in the United States as IS-95. Latest variations are B-CDMA, W-CDMA, and composite CDMA/TDMA. CDMA is characterized by high capacity and small cell radius, employing spread-spectrum technology and a spe- cial coding scheme. B-CDMA is the basis for 3G UMTS. cdmaOne 1G N-CDMA (IS-95). cdma2000 The new 2G CDMA Memorandum of Understanding (MoU) specification for inclusion in UMTS. The cdma2000 Family of Standards The cdma2000 family of standards includes core air interface, minimum performance, and service standards. The cdma2000 air interface standards specify a spread-spectrum radio interfa