vb.net encoded PDU in SMS (i.)

The encoder of the PDU works as a reverse process of the decoder. It is relatively straightforward to work with the PDU code sent only by the encoder as required . This article explains the coding idea, the specific code please refer to the Blog pduencoder part

I took The PDU code is divided into two parts,SMS and EMS. the EMS section I only provided the Concatenatedshortmessage encoder. This is the code of the long text message, the most used.

SMS Encoding

encode a SMS generally requires the following information:

Tp_data_coding_scheme tp_ud Encoding method

Tp_destination_address the other number

Tp_message_reference Reference Number

Tp_status_report_request Status Report

Tp_user_data User Information

Tp_validity_priod Validity

Servicecenternumber SMS Center number

so there are the above attributes in the encoder, and the A processing code is added to the set to convert the readable information into the corresponding hexadecimal information.

the special attention is the Tp_user_data property, which automatically sets tp_udl based on user data encoding . For pure English encoding,tp_udl is the number of characters; for Unicode encoding, because one character is represented by two bytes,tp_udl is the number of characters . Note that the length of the Tp_user_data is checked, and the encoded tp_ud length cannot exceed the number of bytes for SMS . In other words , the English characters (140/7*8), Chinese characters .

for Tp_ud code in the decoder also has a description, not to repeat this.

I've also designed several enumeration variables:

Enum_tp_dcs Encoding Method

Enum_tp_sri Status Report

Enum_tp_valid_period Validity

ENUM_TP_VPF Expiration Format

These enumeration variables can simplify the input and also facilitate future expansion.

when the above content is set up, basically a message shelf is out. At this point the call Getsmspducode is combined, the simple hexadecimal stitching together to form a complete PDU code.

Transfer from bbs.sendsms.cn

vb.net encoded PDU in SMS (i.)