Command in PDU format Meaning
06 Length of Short Message Service Center (SMSC) designation
91 Type of address (international)
56 69 48 95 99 Service center number (in swapped octet order)
11 First octet of message
E5 Message reference
0A Length of phone number (in semi-octets)
91 Address type
56 69 29 04 56 Recipient number (in swapped semi-octet order)
20 Protocol identifier
00 Encoding scheme
AD Validity period
0C Length of message (must add 1)
C9 39 E8 FA 76 93 CB 72 73 9D 0D Message

Table 2 Send a Message in PDU Format.
Every SMS message must encode certain fundamental elements of text messaging communications. Here are the commands used by the accompanying sample applications, rendered in hexadecimal PDU format, along with their descriptions.