Wireless Data Developer Program
Migrating from CDPD to GPRS
Developer Guide
Document Number 12253 Revision 1.0 Revision Date 10/31/02
AT&T Wireless Developer Program © 2002 AT&T Wireless. All rights reserved.
Legal Disclaimer
This document and the information contained herein (collectively, the "Information") is provided to you (both the individual receiving this document and any legal entity on behalf of which such individual is acting) ("You" and "Your") by AT&T Wireless Services, Inc. ("AWS") for informational purposes only. AWS is providing the Information to You because AWS believes the Information may be useful to You. The Information is provided to You solely on the basis that You will be responsible for making Your own assessments of the Information and are advised to verify all representations, statements and information before using or relying upon any of the Information. Although AWS has exercised reasonable care in providing the Information to You, AWS does not warrant the accuracy of the Information and is not responsible for any damages arising from Your use of or reliance upon the Information. You further understand and agree that AWS in no way represents, and You in no way rely on a belief, that AWS is providing the Information in accordance with any standard or service (routine, customary or otherwise) related to the consulting, services, hardware or software industries. AWS DOES NOT WARRANT THAT THE INFORMATION IS ERROR-FREE. AWS IS PROVIDING THE INFORMATION TO YOU "AS IS" AND "WITH ALL FAULTS." AWS DOES NOT WARRANT, BY VIRTUE OF THIS DOCUMENT, OR BY ANY COURSE OF PERFORMANCE, COURSE OF DEALING, USAGE OF TRADE OR ANY COLLATERAL DOCUMENT HEREUNDER OR OTHERWISE, AND HEREBY EXPRESSLY DISCLAIMS, ANY REPRESENTATION OR WARRANTY OF ANY KIND WITH RESPECT TO THE INFORMATION, INCLUDING, WITHOUT LIMITATION, ANY REPRESENTATION OR WARRANTY OF DESIGN, PERFORMANCE, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, OR ANY REPRESENTATION OR WARRANTY THAT THE INFORMATION IS APPLICABLE TO OR INTEROPERABLE WITH ANY SYSTEM, DATA, HARDWARE OR SOFTWARE OF ANY KIND. AWS DISCLAIMS AND IN NO EVENT SHALL BE LIABLE FOR ANY LOSSES OR DAMAGES OF ANY KIND, WHETHER DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, PUNITIVE, SPECIAL OR EXEMPLARY, INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, LOSS OF GOODWILL, COVER, TORTIOUS CONDUCT OR OTHER PECUNIARY LOSS, ARISING OUT OF OR IN ANY WAY RELATED TO THE PROVISION, NON-PROVISION, USE OR NON-USE OF THE INFORMATION, EVEN IF AWS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH LOSSES OR DAMAGES.
i Developer Guide AT&T Wireless Confidential and Proprietary 10/31/02 12253 Rev. 1.0 Use pursuant to Company instructions © 2002 AT&T Wireless
Revision History
All marks, trademarks, and product names used in this document are the property of their respective owners.
Date Revision Description 10/31/02 1.0 Initial release
ii Developer Guide AT&T Wireless Confidential and Proprietary 10/31/02 12253 Rev. 1.0 Use pursuant to Company instructions © 2002 AT&T Wireless
Table of Contents
1. Introduction...... 1 1.1 Audience...... 1 1.2 Contact Information ...... 2 1.3 Resources ...... 2 1.4 Terms and Acronyms...... 2 2. Technology Overview...... 5 2.1 GPRS Compared to CDPD ...... 6 2.2 GPRS Capabilities and Architecture ...... 7 2.3 Evolution and Comparison ...... 10 3. Software Considerations ...... 13 3.1 IP Addressing ...... 13 3.2 Mobile-Terminated Communications ...... 15 3.3 Pricing Considerations ...... 16 3.4 Throughput and Latency ...... 16 3.5 New GPRS Application Features...... 17 3.6 Wireless Application Protocol (WAP) ...... 17 3.7 Evolution of GPRS to EDGE and UMTS ...... 19 4. Integration and Deployment Considerations ...... 20 4.1 Coverage...... 20 4.2 Devices...... 20 4.3 Access Point Names (APN) ...... 21 4.4 Fixed-End Connections ...... 23 4.5 Supporting Both CDPD and GPRS During the Transition ...... 25 4.6 Roaming...... 26 Appendix A. GPRS Protocols...... 27 Appendix B. Managing Data Volume ...... 29 Appendix C. Short Message Service (SMS) ...... 30 Appendix D. GPRS Attachment and PDP Context Activation ...... 31
Figures Figure 1 GPRS Architecture...... 8 Figure 2 Example of GSM/GPRS Time Slot Structure ...... 9 Figure 3 The Evolution of Cellular Technologies ...... 11 Figure 4 Fixed-End Connectivity Options for GPRS ...... 23 Figure 5 GPRS Protocols (User Plane)...... 27
iii Developer Guide AT&T Wireless Confidential and Proprietary 10/31/02 12253 Rev. 1.0 Use pursuant to Company instructions © 2002 AT&T Wireless
Table of Contents
Tables Table 1 Glossary of Terms and Acronyms ...... 2 Table 2 Summary of Differences Between GPRS and CDPD...... 6 Table 3 Summary of Access for Different APNs...... 23 Table 4 Fixed-End Connectivity Options for CDPD and GPRS...... 24
iv Developer Guide AT&T Wireless Confidential and Proprietary 10/31/02 12253 Rev. 1.0 Use pursuant to Company instructions © 2002 AT&T Wireless Migrating from CDPD to GPRS
1. Introduction
This document explains how developers and customers can migrate applications from Cellular Digital Packet Data (CDPD) to General Packet Radio Service (GPRS), an evolved and powerful wireless-data technology.
CDPD technology has proven to be an extremely effective wireless technology, enabling a multitude of mobile applications over nearly a decade. CDPD revolutionized wireless data communications, being the first packet-data service to operate on cellular networks and to support the Internet Protocol (IP). In conjunction with CDPD, AT&T Wireless (AWS) has offered digital PCS voice services based on the ANSI standard 136 (See Section 1.3, Resources).
Over this same period, Global System for Mobile Communications (GSM) has become the most successful cellular technology worldwide, representing over 70% of the global cellular market, with 747 million subscribers in September 2002 (Source: GSM Association, see Section 1.3 Resources). Originally deployed in Europe, GSM is now available in nearly every country around the world. AWS has made a strategic decision to migrate its technology from TDMA and CDPD to GSM, which includes GPRS packet-data service. As discussed below, GPRS provides its users with significant advantages over CDPD.
For developers and customers using CDPD today, AWS is providing thorough support to facilitate the migration of applications from CDPD to GPRS, including both WAP and non-WAP applications. For most customers, this migration will be relatively straightforward as the capabilities of GPRS are essentially a superset of those of CDPD. This document describes the principle considerations and approaches in this migration. The document is in three sections: Technology Overview, Software Considerations, and Integration and Deployment Considerations. Appendices are included that provide additional reference information. This document also references supporting documents and information that aid in this migration.
1.1 Audience
This document is intended for use by AWS alliances, enterprise customers, and independent developers who are migrating applications from CDPD to GPRS.
1 Developer Guide AT&T Wireless Confidential and Proprietary 10/31/02 12253 Rev. 1.0 Use pursuant to Company instructions © 2002 AT&T Wireless Migrating from CDPD to GPRS
1.2 Contact Information