MOMT is the common messaging mode for forwarding SMS from one subscriber to another subscriber.
- When the sender composes and sends a SMS to a destination, MAP Mobile Originated Forward Short Message (MOFSM) is initiated from the serving MSC to the SMSC GT which is usually present in the sender subscriber SIM.
- On receiving MOFSM , SMSC performs various validations such as source number , destination number , SMS content analysis and on successful validation returns MOFSM acknowledgment. Sender will receive an acknowledgment on handset if enabled , indicating message is accepted by SMSC for delivery
- 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