d nations, have deployed cdmaOne. There are about 100 million subscribers in North America in 2002. 10.1.1 cdmaOne services The service of cdmaOne is primarily voice telephone calls, but there are three cate- gories of data service in cdmaOne: short message service (SMS), asynchronous data and facsimile (fax), and packet data services. Voice service in cdmaOne has evolved beyond the original IS-95 standard of IS-96A code excited linear prediction (CELP) speech coding using rate set 1 (RS1), 8.55 kbps. In the next section we point out the enhanced variable-rate codec (EVRC) and a higher- bit-rate codec using rate set 2 (RS2), 13 kbps. SMS is the service described in Chap. 20 that allows subscribers to send messages up to 160 bytes in length. Typically, recipients of short messages are other mobile sub- scribers, but there are also SMS subscribers outside the wireless telephone network. These short text messages have a function similar to text paging. SMS user messages are data carried on the signal channel without requiring call setup and without using a dedicated channel. 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 Worldwide CDMA Standards Asynchronous data and facsimile are circuit-switched data services with a dedicated data path for the duration of a call. Data rates of up to 14.4 kbps are supported by the Radio Link Protocol (RLP) with automatic repeat request (ARQ), forward error correction (FEC), and flow control. ARQ is an error-control protocol in data transmission. The ARQ receiver automatically requests the transmitter to resend the packet when it detects an error in the packet. Efficient ARQ and error correction can bring the error rates down from typical cellular channel bit error rate (BER) values of 10-2 to acceptable data trans- mission values of 10-6.3 With IS-95B, up to eight RS1 or RS2 channels 