SMS MO(Mobile Originated) and MT(Mobile Terminated) 

 SMS MO(Mobile Originated) and MT(Mobile Terminated) Call Flow Example on YateSMSC Equipment

   In the following article we will explain the MO and MT call flow on YateSMSC equipment. 

Based on the following figure we are assuring that UE using MSISDN: +1414361-1234 is sending SMS to UE with MSISDN: +1414361-4321.  MSISDN is the phone number used to connect with a specific mobile user on a specific network and it is made up of three elements: Country Code (CC) National Destination Code (NDC) Subscriber Number (SN).

SMS delivery from +1414361-1234 to +1414361-4321 will contain two main phases:

– First phase when SMS is travelling from mobile subscriber with MSISDN +1414361-1234 to YateSMSC which is referred as Mobile Originated (MO).

– Second phase when SMS is travelling from YateSMSC to mobile subscriber +1414361-4321 which is referred as Mobile Terminated (MT).

 

SMS Mobile Originated and Mobile Terminated Call Flow 

The diagram below illustrates the message flow and signals between YateSMSC and various network elements when SMS is sent from subscriber +1414361-1234 to subscriber +1414361-4321. 

Behind SMS, there are standard telecommunication protocols such as SS7 (Signaling System No.7)/MAP (Mobile Application Part) and SMPP (Short Message Peer to Peer Protocol). SS7/MAP supports communication between core network elements. The SMPP protocol is TCP/IP based and it is responsible for communication between SMS center (in our case YateSMSC) and ESME (external short messaging entity). YateSMSC also supports JSON API over HTTP delivery for easy application development.

 

This are the steps for the entire SMS process from mobile originating part (MO) to mobile terminating part(MT):

 

•  The SMS-SUBMIT is the MO FSM message (mobile originating forward short message) which is between origin MSC and  YateSMSC.

 

• The message received by SMSC is acknowledged to the origin subscriber +1414361-1234 by SMS-SUBMIT REPORT and it gets indication message as “message sent” from YateSMSC.

 

• YateSMSC gets the required information from HLR regarding destination MSC/VLR to route the SMS. This information is obtained by SRI SM request (send routing information for short message). HLR responds the required information to YateSMSC in RESP message.

 

• After receiving the routing information YateSMSC delivers the message to respective destination MSC/VLR, which in turn delivers the SMS to our subscriber with MSISDN +1414361-4321. The same is indicated in the figure by MT-FSM and MT-FSM ACK (Mobile Terminating Part-Forward Short Message Acknowledged).

 

• Once the SMS is delivered to +1414361-4321, the UE with MSISDN: +1414361-1234 gets indication message as “message delivered” OR “message successfully delivered”. The same is mentioned by SMS-STATUS REPORT in our figure.

 

Please note that connection from +1414361-1234 and +1414361-4321 is with the BTS (Base Transceiver Station) as shown and BTS is connected with BSC (Base Station Controller) and BSC is interfaced with the MSC (Mobile Switching Centre)

 

 

SMS MO(Mobile Originated) and MT(Mobile Terminated)  1

Testing Mobile Originated and Mobile Terminated SMS using YateSMSC

We can send SMS from YateSMSC console using the following steps:
        Step 1. Enter the YateSMSC console from Linux using command: telnet 0 5043
        Step 2. In YateSMSC enter Command: smsc send +14143611234 +14143614321 testing

SMS MO(Mobile Originated) and MT(Mobile Terminated)  2

SMS was received on UE with MSISDN +14143614321 from MSISDN +14143611234

SMS MO(Mobile Originated) and MT(Mobile Terminated)  3

Sending SMS using JSON API Request from Linux console using curl command: 

curl -X POST http://127.0.0.1/api.php -H ‘Content-Type: application/json’ -d ‘{“request”: “schedule_sms”,”params”: {“originator”:”+14143611234″,”destination”:”+14143614321″,”text”:”testing2″}}’ 

SMS MO(Mobile Originated) and MT(Mobile Terminated)  4

SMS was received on UE with MSISDN +14143614321 from MSISDN +14143611234

SMS MO(Mobile Originated) and MT(Mobile Terminated)  5

We can see the delivered SMSs in the YateSMSC console using the command: smsc list delivered

SMS MO(Mobile Originated) and MT(Mobile Terminated)  6

Sniffed ‘call.route’ message from YateSMSC Equipment

SMS MO(Mobile Originated) and MT(Mobile Terminated)  7

YateUCN
Unified LTE/GSM+GPRS core network, including SGSN, GGSN, GMSC, MME, SGW, PGW
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