COMMZGATE Web API supports the sending of concatenated long messages.

The API  parameter “UserHeader” is used when sending special binary formatted message (melodies, pictures etc) or when concatenating multipart messages into 1 long message.

The data sent in the UserHeader corresponds to the User-Data-Header segment within Transport Protocol Data Unit (PDU) as defined in the GSM specifications (3GPP TS 23.040).

An example UserHeader for sending a long concatenated message is

 0500030F0201

In this example UserHeader the first 3 Octets 050003 represent the standard identifier for a concatenated message:

05--User Data Header Length (5 octets)

00--Concatenated message (8-bit reference)

03--Information Element Data Length

The next 3 Octets are described as follows:

0F--Concatenated Message Reference. This is a modulo 256 number which remains the same for all segments composing a concatenated message.

02--Total Message Parts (value 0-255) . This number represents the number of segments composing the concatenated message.

01--Part Number of this Segment (value 0-255). The first segment of a concatenated message has a sequence number of 1. Value 0 is reserved.

Further examples of User Header settings can be obtained from each respective handset manufacturers’ SMS specification documents. (eg. Nokia Smart Message FAQ)

As long as the required binary User Data Header info is submitted in the UserHeader parameter and the rest of the binary message body in the Message parameter, the SMS will be delivered as specified.

When sending concatenated  ASCII messages, 7 characters are reserver for the User Header, hence the  message content is restricted only 153 characters per message part.