Binary Content User Data Headers

User Data Headers (UDH) are required for sending binary messages and are specific to the make of the handset that the message is sent to. The data header tells the particular handset the type of binary content and therefore how it should be treated.

Binary messages can be used to send operator logos, ringtones, VCards, WAP push and more.

Here are some example UDH's for a Nokia phone:

• Operator logo: 060504415820000
• Ringtone: 06050415810000
• WAP Push: 0605040B8423F0
• VCard: 06050423F423F4

These are defined in Nokia's Smart Messaging specification. Sony Ericsson have done likewise at http://developer.sonyericsson.com.

You may also wish to see our articles on Concatenation Headers and Binary SMS.