First octet of the SMS-SUBMIT PDU

The first octet of the SMS-SUBMIT PDU has the following layout:

Bit no76543210
NameTP-RPTP-UDHITP-SRRTP-VPFTP-VPFTP-RDTP-MTITP-MTI

where the fields have the following meaning:

FieldnameMeaning
TP-RPReply path. Parameter indicating that reply path exists.
TP-UDHIUser data header indicator. This bit is set to 1 if the User Data field starts with a header
TP-SRRStatus report request. This bit is set to 1 if a status report is requested
TP-VPFValidity Period Format. Bit4 and Bit3 specify the TP-VP field according to this table:
bit4 bit3
0 0 : TP-VP field not present
1 0 : TP-VP field present. Relative format (one octet)
0 1 : TP-VP field present. Enhanced format (7 octets)
1 1 : TP-VP field present. Absolute format (7 octets)
TP-RDReject duplicates. Parameter indicating whether or not the SC shall accept an SMS-SUBMIT for an SM still held in the SC which has the same TP-MR and the same TP-DA as a previously submitted SM from the same OA.
TP-MTIMessage type indicator. Bits no 1 and 0 are set to 0 and 1 respectively to indicate that this PDU is an SMS-SUBMIT

Example

A first octet of "11" (hex) has the following meaning:

Bit no76543210
NameTP-RPTP-UDHITP-SRRTP-VPFTP-VPFTP-RDTP-MTITP-MTI
Value00010001