TP-Message-Refernce

The TP-Message-Reference field gives an integer representation of a reference number of the SMS-SUBMIT or SMS-COMMAND submitted to the SC by the MS. The MS increments TP-Message-Reference by 1 for each SMS-SUBMIT or SMS-COMMAND being submitted. The value to be used for each SMS-SUBMIT is obtained by reading the Last-Used-TP-MR value from the SMS Status data field in the SIM card and incrementing this value by 1. After each SMS-SUBMIT has been submitted to the network, the Last-Used-TP-MR value in the SIM is updated with the TP-MR that was used in the SMS-SUBMIT operation. The reference number may possess values in the range 0 to 255. The value in the TP-MR assigned by the MS is the same value which is received at the SC.

In the case where no response or an RP-ERROR with an appropriate cause value is received in response to an SMS-SUBMIT, then the MS shall automatically repeat the SMS-SUBMIT but must use the same -MR value and set the TP-RD bit to 1. The number of times the MS automatically repeats the SMS-SUBMIT shall be in the range 1 to 3 but the precise number is an implementation matter. The automatic repeat mechanism should be capable of being disabled through MMI.

If all automatic attempts fail, the user shall be informed. The failed message shall be stored in the mobile in such a way that the user can request a retransmission using the same

TP-MR value, without the need to re-enter any information. Such storage need only be provided for a single failed message, i.e. the one most recently attempted.

The SC should discard an SMS-SUBMIT which has the TP-RD bit set to a 1 and which has the same TP-MR value as the previous SMS-SUBMIT received from the same originating address. In the case of a discarded SMS-SUBMIT, the SC should respond with an RP-ERROR, in which case the RP-ERROR shall include a SMS-SUBMIT-REPORT with TP-FCS indicating “SM Rejected – Duplicate SM”. In some cases, for backward compatibility with earlier phases and versions of this specification, the SC may be configured to respond with an RP-ACK.

The SMS-STATUS-REPORT also contains a TP-Message-Reference field. The value sent to the MS shall be the same as the TP-Message-Reference value generated by the MS in the earlier SMS-SUBMIT or SMS-COMMAND to which the status report relates.