National language shift

Along with the standard features of SMPP 3.4, we also provide the National Language Shift functionality which enables you to use special characters from language-specific character sets. National Language Shift Tables are character sets that are customized for specific characters according to the language, the list of supported languages can be found in the table below.

Using the extended character sets, you can send messages with language-specific special characters at the same price as standard GSM-7 messages. As an example, Turkish locking shift characters like ğ, Ğ, € are then at the cost of a single GSM-7 character⁠—there is no need for Unicode messages that would limit the total message amount down to 70 characters. Using the UDH we only reduce the message to 155 characters (since UDH takes up additional space in the message payload).

When a single shift of a particular character set is used, each extended letter will take up double space because an invisible space character has to be used to access the shift table.

For example, when using Spanish NLI Ú is only accessible in the single shift character set extension, which requires the use of an escape character. With each new single shift character introduced, the message length reduces by 1 respectively. This means in case there are 3 single shift characters, the default limit of 155 characters per NLI message is reduced to 152.

Example:

1B55 (1B is the escape character, 55 is Ú that is used from the extended character set)

Language selection is possible by using language identifiers within the UDH part of the message payload. The IEI (Information-Element-Identifier) specifies whether the single or locking shift will be used.

• ESM class parameter, in this case, must be defined to 64.
• Data coding values that can be used are 0 or 1.

Locking Shift Example UDH

UDH Length	IEI (Information Element Identifier)	IE Length	Selected shift
03	25	01	01
Remaining UDH length in bytes	National Language Locking Shift		Locking Shift - Turkish

Single Shift Example UDH

UDH Length	IEI (Information Element Identifier)	IE Length	Selected shift
03	24	01	02
Remaining UDH length in bytes	National Language Single Shift		Single Shift - Spanish

UDH Identifier Reference

Below is a UDH reference for each language and here’s a detailed character set reference for GSM 7.

Language	Single Shift	Locking Shift	UDH Identifier
Reserved	Basic	Basic	0x00
Turkish	Turkish	Turkish	0x01
Spanish	Basic	Spanish	0x02
Portuguese	Portuguese	Portuguese	0x03
Bengali	Bengali	Bengali	0x04
Gujarati	Gujarati	Gujarati	0x05
Hindi	Hindi	Hindi	0x06
Kannada	Kannada	Kannada	0x07
Malayalam	Malayalam	Malayalam	0x08
Oriya	Oriya	Oriya	0x09
Punjabi	Punjabi	Punjabi	0x0A
Tamil	Tamil	Tamil	0x0B
Telugu	Telugu	Telugu	0x0C
Urdu	Urdu	Urdu	0x0D