Ozeki NG SMS Gateway

Data Coding Scheme (TP-DCS)

The TP-Data-Coding-Scheme field, defined in GSM 03.40, indicates the data coding scheme of the TP-UD field, and may indicate a message class. Any reserved codings will be assumed to be the GSM default alphabet (the same as codepoint 00000000) by a receiving entity. The octet is used according to a coding group which is indicated in bits 7..4. The octet is then coded as follows:

Coding Group Bits 7..4Use of bits 3..0
00xxGeneral Data Coding indication
Bits 5..0 indicate the following:
Bit 5
0Text is uncompressed
1Text is compressed

Bit 4
0Bits 1 and 0 are reserved and have no message class meaning
1Bits 1 and 0 have a message class meaning

Bit 3Bit 2Alphabet being used
00Default alphabet
018 bit data
10UCS2 (16bit)

Bit 1Bit 0Message classDescription
00Class 0Immediate display (alert)
01Class 1ME specific
10Class 2SIM specific
11Class 3TE specific

NOTE: The special case of bits 7..0 being 0000 0000 indicates the Default Alphabet as in Phase 2

0100..1011Reserved coding groups
1100Message Waiting Indication Group: Discard Message

Bits 3..0 are coded in exactly the same way as Group 1101, however, with bits 7..4 set to 1100 the mobile may discard the contents of the message, and only present the indication to the user.

1101Message Waiting Indication Group: Store Message This Group allows an indication to be provided for the user about the status of types of message waiting on systems connected to the GSM PLMN. The mobile may present this indication as an icon on the screen, or another MMI indication. The mobile may take note of the Origination Address for the message in this group and group 1100. For each indication supported, the mobile may provide storage for the Origination Address which is to control the mobile indication.
Text included in the user data is coded in the Default Alphabet.
Where a message is received with bits 7..4 set to 1101, the mobile will store the text of the SMS message in addition to setting the indication.
Bit 3Description
0Set Indication Inactive
1Set Indication Active

Bit 2 is reserved, and set to 0

Bit 1Bit 0Indication Type
00Voicemail Message Waiting
01Fax Message Waiting
10Electronic Mail Message Waiting
11Other Message Waiting*
* Mobile manufacturers may implement the "Other Message Waiting" indication as an additional indication without specifying the meaning. The meaning of this indication is intended to be standardized in the future, so Operators should not make use of this indication until the standard for this indication is finalized.
1110Message Waiting Indication Group: Store Message The coding of bits 3..0 and functionality of this feature are the same as for the Message Waiting Indication Group above, (bits 7..4 set to 1101) with the exception that the text included in the user data is coded in the uncompressed UCS2 alphabet.
1111Data coding/message class

Bit 3 is reserved, set to 0.

Bit 2Message coding
0Default alphabet
18-bit data

Bit 1Bit 0Message ClassDescription
00Class 0Immediate display (alert)
01Class 1ME specific
10Class 2SIM specific
11Class 3TE specific

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