TP-PID Text Message Protocol identifier

TP-PID Text Message Protocol identifier(3GPP 23.040)

1) its definition in the Protocol: the Protocol-identifier is the information element by which the SM-TL either refers to the higher layer protocol being used, or indicates

Interworking with a certain type of telematic device.

The Protocol identifier is an information element, through which the SM-TL (Short Message Transport Layer) can either be referenced to use higher level protocols, either imply interaction with a specific type of information communication device.

2) It occupies an 8-bit group in the pdu. The allocation of each bit is as follows:

Bit No. 7 6
0 0 as defined in the allocation bit no.0-bit No. 5 below (usually set to 00)
0 1 See full definition of the gsm03.40 protocol logo
1 0 Reserved
1 1 Allocation of bit no.0-bit No. 5 for special purposes of the service center (SC)

When bit No. 7 = 0 and bit No. 6 = 0, the value of bit No. 5 is as follows:

0-No remote network is used, but the protocol between Short Message devices;

1-use a remote network

When bit 5 is set to 1, bit no.0-bits No. 4 indicates the network type used. The values are as follows:
Bit no.0-bits No. 4:
00000-implicit;
00001-telex;
00010-group 3 Telefax;
00100-voice;
00101-European wireless Information System (ERMES );
00110-domestic system;
10001-any x.400-based public information processing system;
10010-email...

If bit 5 = 1 appears in the PDU of the SMS-SUBMIT, it implies that the SME (Short Message entity) is a device determined by the value of bit no.0-bits No. 4, then it also requires SC to be able to convert Sm to a type suitable for their own reception.
If bit 5 = 1 appears in the PDU of the SMS-DELIVER, it indicates that the receiving end SME is a device determined by the value of bit no.0-bits No. 4.
If bit 5 = 0 appears in the PDU of the SMS-DELIVER, the value of bit no.0-bits No. 4 is used to identify the SM-AL (Short Message application layer) protocol between SME and Ms.

In standard cases, MS-to-SC short message transmission only needs to set this domain to 00 (indicating standard point-to-point communication ).

Well, you just need to know about it. I personally have a limited level. I hope to share this with you and give you some help.