Application Originated Mobile Terminated (AOMT) Message Flow
AOMT is one of the widely used modes in SMSC by external clients for sending SMS such as advertisements , One time passwords (OTP) , application specific notifications etc. this example to explain the flow, it is assumed External
application is interfaced to SMSC on SMPP protocol and with operator network MSC over
SIGTRAN / SS7
- External application bind to SMSC on SMPP
protocol as transceiver submits a message using SUBMIT_SM operation to SMSC which
includes info on source number, destination number, SMS content
- SMSC on receiving the message and validation acknowledges with a SUBMIT_SM_RSP. A unique reference number allocated to the message is returned in this response. Later when SMSC generates Delivery Status Report (DSR) , it will be referenced with same message ID
- SMSC after successful validation, initiates a MAP Send Routing Info for Short Message (SRI-SM) to HLR of the destination number to collect the VLR details of the destination number to which SMS has to be forwarded.
- HLR of the destination number which has the current VLR address under which subscriber is present, returns VLR number in SRISM response
- SMSC decodes the VLR GT of destination number from this SRISM response, frames the MAP MTFSM message and forwards to the VLR GT
- VLR performs the paging procedure to locate the exact location where the destination number is present, forward the short message
- On successful paging and message delivery and acknowledgment from the mobile station, returns a positive MTFSM acknowledgment to SMSC
- SMSC then on decoding the MTFSM response, submits a DSR through DELIVER_SM operation to the external application over SMPP with the same message reference number which was sent in SUBMIT_SM_RSP and Delivery Status