MT Message Flow

MT messages are the messages which are terminated from the mobile phone. The origination of the MT messages is the SMSC. This is somewhat complex process compared with the MO flow which had less number of steps.

The message flow of the MT messages is explained in the picture below.

Step 1

Accept the submission of MT messages to the relevant module in the SMSC. Origination of this messages could be from an applications or could be a MO message.

Step 2

Then for message is to be sent, SMSC access HLR (Home location register) to obtain the location information for a particular user. HLR replies with the relevant information

Step 3

Then the message is transferred to required MSC with the relevant information which would need for MSC to proceed.

Step 4

In step 4, authentication and other information

Step 5

Message is then actually sent to the subscriber. At this stage VLR is updated changing the status of the SMS delivery.

Step 6

Status report of the message is then sent to SMSC.

Step 7

Finally SMSC will update the relevant personal information on HLR and message is then sent to the next step processing