Introduction to mobile data
Introduction to Mobile Data Circuit Switched, Packet Switched, Mobitex, CDPD, and GPRS Lawrence Harte Excerpted From: Wireless Systems With Updated Information ALTHOS Publishing Packet Switched Data TCP/IP Protocol Information Services General Packet Radio Service (GPRS) ALTHOS Publishing Copyright © 2004 by the ALTHOS Publishing Inc. All rights reserved. Produced in the United States of America. Except as permitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without prior written permission of the publisher. ISBN: 0-9746943-9-8 All trademarks are trademarks of their respective owners. We use names to assist in the explanation or description of information to the benefit of the trademark owner and ALTHOS publishing does not have intentions for the infringement of any trademark. 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ALTHOS and/or its licensors shall not be liable for any damages including incidental, indi- rect, punitive, special, consequential or similar types of damages that may result from the attempted use or operation of the work. -ii- Copyright ©, 2004, ALTHOS, Inc -iii- Copyright ©, 2004, ALTHOS, Inc About the Author Mr. Harte is the president of Althos, an expert information provider covering the communications industry. He has over 29 years of technology analysis, development, implementation, and business management experience. Mr. Harte has worked for leading companies including Ericsson/General Electric, Audiovox/Toshiba and Westinghouse and consulted for hun- dreds of other companies. Mr. Harte continually researches, analyzes, and tests new communication technologies, applications, and ser- vices. He has authored over 30 books on telecommunications technologies on topics including Wireless Mobile, Data Communications, VoIP, Broadband, Prepaid Services, and Communications Billing. Mr. Harte’s holds many degrees and certificates include an Executive MBA from Wake Forest University (1995) and a BSET from the University of the State of New York, (1990). -iv- Copyright ©, 2004, ALTHOS, Inc -v- Copyright ©, 2004, ALTHOS, Inc Table of Contents INTRODUCTION TO MOBILE DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 M ARKET DECLINE AND GROWTH . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 TECHNOLOGIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Circuit Switched Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 Packet Switched Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Sub-Band Data Transmission . . . . . . . . . . . . . . . . . . . . . . . . . .8 Shared Voice and Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Wireless Modem Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Modem Pools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 Internet Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 General Packet Radio Service (GPRS) . . . . . . . . . . . . . . . . . . .14 W IRELESS DATA APPLICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Credit Card Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Parking Meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Vending . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 Environmental Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 Energy Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 Dispatch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 Utility Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 Wireless E-mail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 Wireless Internet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 Mobile Computing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 Advertising . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 Vehicle Monitoring Services . . . . . . . . . . . . . . . . . . . . . . . . . . .21 C OMMERCIAL MOBILE DATA SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . 21 Data over Cellular . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 DataTACTM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22 Mobitex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 Cellular Digital Packet Data (CDPD) . . . . . . . . . . . . . . . . . . . .23 -vi- Copyright ©, 2004, ALTHOS, Inc Cellemetrysm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 Aeris Microburst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25 Teletrac . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 Ricochet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 FM Sub-band Signaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 S ERVICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Circuit Switched Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 Packet Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 Wireless Messaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 FUTURE ENHANCEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 High-Speed Packet Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 Introduction to Mobile Data -1- Copyright ©, 2004, ALTHOS, Inc Introduction to Mobile Data Mobile data is the transmission of digital information, through a wireless network, to radios that can typically move throughout a relatively large geo- graphic area. The success of mobile wireless data systems had been limited, until the mid 1990’s, due to the high cost of service and equipment, and lim- ited geographic coverage areas. In the mid 1990’s, service usage and equip- ment costs dropped due to competition and availability of applications and end user devices. Many wireless data systems are now available globally. In addition to the mobile wireless data systems covered in this chapter, there are also many types of short-range wireless data systems. These sys- tems include wireless local loop (WLL), wireless local area network (WLAN) and wireless cable. These short rage wireless systems are covered in chap- ter 9 and chapter 12. The growth of the Internet has also enabled low cost, standardized access to wireless data networks that is accelerating the growth of the wireless data marketplace. In 2003, some dedicated wireless data systems had more then 15 million devices operating in their system (CNET provides wireless elec- tric utility monitoring service). Introduction to Mobile Data -2- Copyright ©, 2004, ALTHOS, Inc Figure 1.1 shows a basic mobile wireless data system. In this system, many types of wireless data devices (mobile data terminals) communicate to near- by base station transmitters using a radio protocol that is unique to this sys- tem. A packet switch is used to route the packets between mobile data ter- minals or through a gateway that connects the mobile data system to the Internet. The packet switch is connected to a subscriber database that is used to determine which services are authorized, where the customer is located (location register), and the amount of services that the customer has used. This diagram shows that base station transmitters typically provide more transmitter power (50 Watts in this example) than the mobile data ter- minals (2 Watts in this example.) Figure 1.1, Mobile Wireless Data System <ag_mobile_ data_system> Introduction to Mobile Data -3- Copyright ©, 2004, ALTHOS, Inc Market Decline and Growth Wide area mobile data systems are transitioning from narrowband (low- speed) mobile data to shared (mobile telephone voice and data) mobile com- munication system. This transition can be confusing as some of the tradi- tional mobile data applications such as wireless credit card machines can now operator using a different type of wireless system. To date, most mobile data applications are non-human in nature and require small amounts of data transfer. The key mobile data applications include monitoring vending machines, utility measurement, providing road sign information, security system, environmental measurements, wireless credit card machines, and hundreds of other applications. Mobile data appli- cations that require human interaction (such as email) are transitioning from low speed data systems to high-speed mobile telephone systems. Figure 1.2 shows the growth rate for packet based wireless data services. This diagram shows the dramatic increase of GSM mobile data users from 2002 through 2003. Figure 1.2, Wireless Data Market Growth Source: EMC Word Cellular Data Technologies There are several wireless technologies that are used for mobile wireless data. These technologies allow data rates to vary from a few kilobytes per second to several hundred kilobytes per second. Wireless data technology is commonly divided into two types of transmis- sion: circuit switched data and packet switched data. Circuit switched data is characterized by the continuous connection between two points. Packet data is identified by the dividing of data into small packets that may take different routes between points. There is a new type of wireless data called “control channel data. Control channel technology utilizes the excess capacity of a wireless system control channel to transmit packets or burst of data. While this technology is usu- ally limited to small amounts of data (a few hundred bytes per message), existing systems can have good coverage area and it is relatively inexpen- sive to upgrade the existing system to provide mobile data services. Circuit Switched Data Circuit switched data is the continuous transfer of data between two points. To establish a circuit switched data connection, the connection address (nor- mally a phone number) is sent first and a connection path is established. After this path is setup, data is continually transferred using this path until the path is disconnected by request from the sender or receiver of data. Circuit switched data would be understood better if it was entitled “A phone- call for data” because a connection (usually a public telephone call) must be made beforehand. After the phone call is connected through the public switched telephone network (like most modems do on home computers), the telephone circuit remains in conversation mode while data is transmitted back and forth between the two devices. For circuit switched data, the tele- phone circuit resources (wires and switching) remain dedicated to (and typ- ically paid for by) the user regardless if data transmission has stopped. Introduction to Mobile Data -4- Copyright ©, 2004, ALTHOS, Inc [...]... used to convert radio data into data that can be Copyright ©, 2004, ALTHOS, Inc -21- Introduction to Mobile Data sent through the network (such as to the Internet) Some cellular systems do not include this equipment (it can be expensive for a cellular operator to offer data capability) or the cellular service provider may not offer the data service DataTACTM The DataTAC system uses the advanced radio data. .. consumer electronics in automobiles In one application, if the car develops a fault (breaks down), a wireless data transmitter automatically calls for help to the nearest location and begins transmitting stored computer data to aid in diagnosis of the problem that is likely occurring Commercial Mobile Data Systems The commercial mobile data systems include sending data over cellular (mobile telephone), ARDIS,... wireless data systems do not directly use TCP/IP They usuCopyright ©, 2004, ALTHOS, Inc -12- Introduction to Mobile Data ally have protocol adapters that allow the conversion of their proprietary protocol to TCP/IP protocol This allows most wireless data systems to offer interconnection to the Internet (while keeping the airlink usage to a minimum) Figure 1.7 shows how transaction control protocol (TCP).. .Introduction to Mobile Data Figure 1.3 shows a circuit switched data system In this figure, a computer is sending a data file through a circuit switched data communications network to a home office computer To start the data file transfer, the computer sends the destination address (address 202.196.22.45) to the data network The destination address is used to program the switches... starting to find its way into wireless devices Already, some cellular phone systems automatically call a roaming customer that has entered into their system to inform them that they are authorized to use the service in their system Wireless data can be used to send advertising messages to billboards, displays on vending machines or to set top boxes that display text or graphics on televisions or monitors... receivers that can separate the data signal from the audio broadcast signal Figure 1.5, Sub-Band Data System Copyright ©, 2004, ALTHOS, Inc -9- Introduction to Mobile Data Shared Voice and Data Shared voice and data systems allow data transmission on radio channels when voice communication is not in process The concept of shared voice and data allows a voice system to offer data services during idle radio... ALTHOS, Inc -11- Introduction to Mobile Data Mobile data systems adapt the radio protocols (protocol adaptation) to the protocols that are used in the landline or data communication network This process may involve syntax changes (text format and command name changes,) timing relationships, and other functional processes Modem Pools Modem pools are the inter-working functions between a mobile radio modem... routes to reach their destination When the 3 packets reach their destination, the remote computer reassembles the data packets into the original data file Figure 1.4, Packet Switched Data Copyright ©, 2004, ALTHOS, Inc -7- Introduction to Mobile Data The question of choice between using circuit switched data and packet switched data is often an easy one, but the choice may not be predicated totally... cellular telephones to take advantage of information on the web without transferring large quantities of data Mobile Computing Mobile computing provides the ability for mobile workers to connect to information sources while on the road Mobile computing can involve a combination of wired and wireless connection Typical applications for mobile computing include sales force automation, inventory tracking and... cellular system is used To send data over digital cellular systems, a data adapter is used to convert the data signals from the computing device to the format that is required by the digital cellular telephone This data transfer function may be built into the cellular phone or into the computing device (such as a portable computer) While it is may be possible to directly transfer data files via digital . 31 High-Speed Packet Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 Introduction to Mobile Data -1- Copyright ©, 2004, ALTHOS, Inc Introduction to Mobile Data Mobile data is the transmission. [ 1 ]. Introduction to Mobile Data -12- Copyright ©, 2004, ALTHOS, Inc Mobile data systems adapt the radio protocols (protocol adaptation) to the protocols that are used in the landline or data. paid for by) the user regardless if data transmission has stopped. Introduction to Mobile Data -4- Copyright ©, 2004, ALTHOS, Inc Introduction to Mobile Data -5- Copyright ©, 2004, ALTHOS, Inc Figure