Graw-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. GPRS Introduction GPRS Introduction Figure 2-8 The timeline for packet-switched data. wireless users. In addition, limited support for SMS was introduced to offer paging-like and text-messaging services. In second-generation (2G) wireless networks, SMS services became the deployed architecture of choice. It uses the existing infrastructure of 2G wireless networks, with the addition of the Message Center component. 2G also introduced asynchronous data and facsimile services over the air inter- faces, with initial data rates of up to 14.4 Kbps. This enables users to fax and have dial-up access to an ISP account, corporate account, and the like. Packet data technology gained momentum in 2G and then on to 2.5G net- works. This includes GPRS and packet data support in Code Division Mul- tiple Access (CDMA). Data rates for the packet switching currently range from 9.6 to 19.2 Kbps. In the future of 2G, we can expect to see data rates at up to 115 Kbps. 3G, when it happens, will support data rates of 384 Kbps to 2 Mbps. Mul- timedia and high-speed Internet access will be the expected normalized data access applications. Wireless Data Technology Options Today, GSM has the capability to handle messages via the SMS and 14.4-Kbps circuit-switched data services for data and fax calls. The maxi- mum speed of 14.4 Kbps is relatively slow compared to the wireline modem 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. GPRS Introduction Chapter 2 speeds of 33.6 and 56 Kbps. To enhance the current data capabilities of GSM, operators and infrastructure providers have specified new extensions to GSM Phase II, as shown in Figure 2-9, to provide High-Speed Circuit-Switched Data (HSCSD) by usi