Mobile Communication

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Mobile Communication
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Mobile Communication

• Transaction/Submit, deliver, report and command

At the transfer layer SIX types of transactions
can occur between a SME and the SMSC

• SMS-Submit
• This transaction corresponds to the submission of
  the message from SME to SMSC. The SMSC
  acknowledges the submission with
  SMS-SUBMIT-REPORT
• SMS-Deliver
• This transaction corresponds to the delivery of
  the message from SMSC to SME. The SMSC
  acknowledges the submission with
  SMS-DELIVER-REPORT
• SMS-Status Report
• This transaction corresponds to the transfer of a
  status report from an SMSC back to the SME
• SMS-Command
• This transaction corresponds to the request from
  a SME usually an ESME for a specific command

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Mobile Communication

• Transport Protocol Data Unit

A TPDU has been assigned to each transaction that
can occur between a SME and an SMSC at the
transfer layer.
High-level parameters in TPDU are bold, TP-MTP,
TP-UDHI and TP-UD
TP-UDHI Provides instructions with the presence
of binary elements TP-UD Important parameter
which contains the text part of a message segment
and may also contain binary elements,
instructions, melodies or pictures. The parameter
is divided into two sub-parts UDH Which
contains binary elements while the remaining
contains text.
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Mobile Communication

• Transport Protocol Data Unit

A TPDU has been assigned to each transaction that
can occur between a SME and an SMSC at the
transfer layer.
High-level parameters in TPDU are bold, TP-MTP,
TP-UDHI and TP-UD
TP-UD The UDH then is further divided into
Sub-Parts, the first sub-part UDHL indicates the
length of the UDH in octets. A set of information
elements follow. Whatever the coding the UDH is
always 8bit encoded. If the UDH is 7bit aligned
then fill in bits inserted between UDH and
remaining part of TP-UD. This allows older
handsets that do not support UDH to use 7bit
text
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Mobile Communication
Fig 3.9

• Message Types

The set of possible transaction types in fig 3.9
can occur SMSC and the originator or receiving
SME. A dedicated value assigned to the TP-MTI
corresponds to each transaction type.
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Mobile Communication
Fig 3.9

• Text Coding Schemes

The Two coding schemes used in SMS are GSM 7 bit
default alphabet defined in 3GPP-23.038 and the
Universal Character Set (UCS2) defined in
ISO-10646 The amount of text that can be
included in a message needs to fit in 140 Octets.

• GSM 7bit DA is composed of 128 charactors 9
  additional
• - UCS2is used for encoding complex sets of
  non-latin charators such as Arabic/Chinese

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Mobile Communication

• Message Classes

There are four classes in TP-DCS (data coding
scheme) of TPDU which indicate which class the
message belongs too.
It has to be noted that most cases, a msg does
not belong to any of the four classes, therefore
a non-class msg is handled as Class 1 or 2 by the
receiving SME
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Mobile Communication

• Coding Groups

A message may belong to one of the three groups.
The coding group indicates what the receiving SME
should do with the message once it has read or
interpreted. The TP-DCS ltData-Coding-Schemegt,
indicates the coding group to which the message
belongs
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Mobile Communication

Protocol Identifier
A message is also associated to a protocol
identifier. The protocol Identifier indicates how
the receiving message application should handle
an incoming message.