User Data Header

User Data Header SearchSearch
Author Message
Anonymous
Posted on Friday, July 11, 2003 - 07:05 pm:   

Where can I find more reference material on User Data Header?
Bryce Norwood - NowSMS Support
Posted on Friday, July 11, 2003 - 07:31 pm:   

What type of reference are you looking for on the User Data Header (UDH)?

Basically, UDH is used in a variety of different ways.

The ETSI GSM 03.40 specification defines how UDH is formatted. You can download this specification at http://www.etsi.org.

The most common use of UDH is for concatenated short messages. Information in the user data header is used by the client to reconstruct a message that has been split into multiple parts.

UDH is also used very heavily by Nokia Smart Messaging and WAP Push. Both of these protocols make use of the application port addressing scheme defined in GSM 03.40. The idea is that messages to different ports can be directed to different applications. So in Nokia Smart Messaging, you send ring tones to a particular port, operator logos to another port, etc. WAP Push also has its own port. The WAP Wireless Datagram Protocol (WDP) Specification has a section on mapping the WAP WDP protocol to GSM SMS which has a pretty good explanation of how both message concatenation and port addressing works in GSM SMS. The WAP WDP spec can be downloaded from the Open Mobile Alliance site at http://www.openmobilealliance.org. The Nokia Smart Messaging spec can be downloaded at http://www.forum.nokia.com.

UDH is also used by EMS, which is an Ericsson-Motorola-Siemens-Alcatel developed specification intended to support features similar to Nokia Smart Messaging, but in a vendor neutral format. It employs a different concept than Nokia Smart Messaging and WAP Push. Instead of port addressing, it defines new UDH elements where pictures and ring tone data are actually embedded in the user data header ... this in contrast to Nokia Smart Messaging, where the picture or ring tone content is in the payload of the message and the UDH just defines a port number. As a result, EMS applications tend to be a little more difficult to develop. The EMS specifications can be found at the Ericsson MobilityWorld site ... http://www.ericsson.com/mobilityworld.

If you have any more specific questions on the subject of UDH, please feel free to ask.

-bn
Anonymous
Posted on Wednesday, August 27, 2003 - 12:53 pm:   

Can i use UDH to send information like userid and password etc.
Bryce Norwood - NowSMS Support
Posted on Friday, September 05, 2003 - 05:26 pm:   

I'm not aware of any UDH fields that would be used for that purpose.

What are you trying to send a userid and password for?