Because the PDU type octet is in hex, the value for PDU type is 01. Putting that value
into our TPDU gives us:
PDU
Type
Message
Reference
Destination
Address
Protocol
Identifier
Data
Coding
Scheme
Validity
Period
User
Data
Length
User
Data
01
1 Octet
2-12 Octets 1 Octet
1 Octet
0,1, or 7
Octets
1 Octet 0-140
Octets
The next parameter of the TPDU is
Message Reference (MR)
. It is the reference
number for the message. The MR should automatically be incremented from 0 to 255. If
the message fails to get delivered, you should use the same MR when resending the
message.
The
Destination Address
is the phone number that receives your SMS message. It
has the format:
Length of
Phone Number
Number
type
Phone Number
If the phone number has an odd number of digits, than you should add an F to make it
an even number. For example 15551234567 would be entered as 5155214365F7 when
storing the phone number with the low nibble first.
The number type is either 91 for a with-international-prefix number or 81 for a
without-international-prefix number.
Unlike when coding the SCA number, the length of the phone number does not include
the number type nor does it include the F used for padding. In our example, the length
of the number is 11 decimal, which is the octet 0B. So assuming an international number,
our Destination address would be:
Length of
Phone Number
Number
type
Phone Number
0B 91 5155214365F7
29
