Understanding the Standards

One of my key ambitions with the book was to give people enough knowledge to be able to use the actual standardization documentation in order to learn more. Books and articles are excellent in order to get into new technical areas and when you need the implementation (reality check) aspect as well. Many of us, however, also sometimes need to get into the depth of the technology and find out exactly what the standard states. Here we sometimes face a challenge, as the standards are somewhat hard to find and navigate through. At times, it is even hard to know who is responsible for a standardization area. In this article, I intend to shed some light over some of the major standardization bodies and help you navigate safely in these unknown waters. This is a one of the few kinds of articles for which I actually prefer the electronic format with its hyperlinks as opposed to the printed version when reading it.

First of all, we have the mobile networks and the associated architectures. Cdma2000 is standardized by 3GPP2, www.3gpp2.org, but here we mainly focus on the other 2.5G and 3G technologies, GPRS, EDGE and WCDMA (UMTS). All of these three are standardized in the 3^rd Generation Partnership Program (3GPP) and available on the Internet. The 3GPP standardization is based on releases, and everything is a migration.

The 3GPP release phases:

Release 1997: GPRS is added to existing GSM systems and adds packet data (Release 1998 is another upgrade to GPRS but not as significant a step). Commercial networks on a broad scale during 2001.

Release 1999 (Release 3): WCDMA (UMTS) is added, with high-speed packet and circuit switched data. Commercial operations expected to start 2002.

Release 4 (The years format have been skipped): Adding more IP multimedia functionality. Standardization finalized March 2001.

Release 5: Standardization targeted to be finalized 1^st half of 2002.

Then for each release of the standard, there is a quarterly update (e.g. 3GPP Rel 3, March 2001) which contains change requests and small corrections.

The 3GPP standards (at www.3gpp.org) can be a bit difficult to read for beginners, although they are freely available on the Web. The page http://www.3gpp.org/3G_Specs/3G_Specs.htm explains the structure and links to the relevant document databases. On the FTP–site, ftp.3gpp.org, there are directories for the different workgroups and the specifications are grouped by 3GPP meetings and releases, e.g. ftp://ftp.3gpp.org/Specs/2000-12/ contains all the specifications resulting from the December 2000 proceedings. Then you just choose what release of the standard you want to look at, for example R1999 to check out the first release of the WCDMA(UMTS) system.

FTP Directory: ftp://ftp.3gpp.org/Specs/2000-12/

 Parent Directory 
 Drafts . . . . . . . . . . . . . Mar 13 12:36        
 Ph1. . . . . . . . . . . . . . . Mar 13 12:37        
 Ph2. . . . . . . . . . . . . . . Mar 13 12:38        
 R1996. . . . . . . . . . . . . . Mar 13 12:39        
 R1997. . . . . . . . . . . . . . Mar 13 12:41        
 R1998. . . . . . . . . . . . . . Mar 13 12:42        
 R1999. . . . . . . . . . . . . . Mar 13 12:44        
 Rel-4. . . . . . . . . . . . . . Mar 13 12:48        
 Rel-5. . . . . . . . . . . . . . Mar 13 12:49        
 status_2000-12.zip . . . . . . . Jan  3 11:17    301k  
 withdrawn. . . . . . . . . . . . Mar 13 12:49        

The tricky part is now how to find the document numbers for these files. The web page http://www.3gpp.org/3G_Specs/spec_titles.htm holds exactly that information and the status file (e.g. ftp://ftp.3gpp.org/Specs/2000-12/status_2000-12.zip also explains how far a document has come. Thus, to find the document TS21.101 you just click on the '21_Series' folder under ' R1999' and the file is found as 21101-320.zip (ftp://ftp.3gpp.org/Specs/2000-12/R1999/21_series/21101-320.zip).

Applications Enablers

Parlay is an organization that drives the standardization of open APIs that developers can use. This includes call control and charging features that usually not are available outside the mobile network(Chapter 9, "Application Architectures."). More information about Parlay is found at http://www.parlay.org/. For the current version of Parlay, 2.1, the specifications are found at http://www.parlay.org/specs/index.asp. 2.1 includes API's for the following functions:

• Call Processing APIs 2.1 [1.6 MB]
• Connectivity Manager APIs 2.1 [600 KB]
• Framework APIs 2.1 [1.1 MB]
• Messaging APIs 2.1 [430 KB]
• Mobility APIs 2.1 [560 KB]
• Common Data & IDL 2.1 [650 KB]

Many of the operators that install a Service Network will support the Parlay API's in order to give developers access to these features.

SyncML is another key enabler that will have a great impact on developers as well as operators. In short, SyncML enables many different devices to synchronize with servers over a standardized, XML-based protocol. Synchronizing your Calendar or e-mail over the air is just a start and later sales databases and other applications will join. The SyncML Forum, http://www.syncml.org/, standardizes SyncML and there is plenty of good info on their webpage. The White Paper, http://www.syncml.org/download/whitepaper.pdf, is a good start and for the techies we find the specifications at  http://www.syncml.org/downloads.html. For operators, SyncML is like a dream because of all the traffic over the air it is expected to generate.

Multimedia Messaging Service (MMS) is standardized in 3GPP and in the WAP Forum and it is a natural evolution for today's messaging technologies. The hugely popular Short Message Service (SMS) has taken the world by storm and has become a huge cash cow for mobile operators. In Q1 2001 alone, over 50 Billion messages where sent world wide! With MMS you can attach send entire multimedia presentations that contain images, sounds, text and later also video clips.  The presentations  can be sent either between mobiles or between mobiles and fixed PC's with e-mail capabilities. WAP is used on top of the bearers to facilitate efficient and robust transport of the messages. TS 22140 and TS 23140 contain the MMS specifications for phase 1 and 2 respectively (Release 1999).

Summary

Reading the standards is not always easy, especially when it comes to the telecoms world. Reading a book only gets you to a certain level and many developers will have to check out some specifics in the specifications in order to get ahead in the development process. Hopefully you now are fit to face this challenge.

About the author: Christoffer Andersson is Senior Specialist and Manager of Special Projects at Ericsson. In this position he works with strategic issues and projects in the area of Terminals & Applications 2G/3G. Christoffer is also author of the Amazon.com best-selling book 'GPRS and 3G Wireless Applications - The Professional Developer's Guide', published in May 2001 by John Wiley & Sons. Christoffer can be reached at christoffer@wirelessdevnet.com.

The opinions expressed in this column are those of the author and not necessarily Ericsson.