Length is 2 plus the number of digits transmitted for the SC phone number, as detailed
below. When calculating the Length, it’s important to remember that it is expressed in
octets; and since each octet is 2 hexadeciimal characters you can count the number of
hexadecimal characters in your SCA and divide by 2.
The Number Type for the SCA is an octet, either 91 for a number that has an
international country code prefix or 81 for one that doesn’t have an international country
code prefix. For instance, 91 is appropriate for the US number 13123149810 and 81 is
appropriate for the US number 3123149810.
The SC Phone Number is the phone number of the SMS center, which can vary in
length. The SC phone number must have an even number of hexadecimal digits, so an
F is sometimes added. Storing the phone number with the low nibble first as explained
above, the SC phone number 13123149810 is expressed as 3121139418F0. The SC
phone number 3123149810 is expressed as 1332418901.
Now let’s assume that we want to create an SCA parameter for a
with-international-prefix number 13123149810. The Length is 2 plus the number of
digits in 3121139418F0, for a total of 14. This is expressed by 7 octets. Therefore the
SCA parameter is 07913121139418F0.
Creating the TPDU Parameter of your PDU
The TPDU Parameter consists of the following fields:
PDU
Type
Message
Reference
Destination
Address
Protocol
Identifier
Data
Coding
Scheme
Validity
Period
User
Data
Length
User
Data
1 Octet 1 Octet
2-12 Octets 1 Octet
1 Octet
0,1, or 7
Octets
1 Octet 0-140
Octets
The bits for the first octet
PDU Type
are as follows:
Reply
Path
User
Data
Header
Status
Report
Validity Period
Format
Reject
Duplicates
Message type
Indicator
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