Tsp (application id: 16777346)

Tsp interface facilitates communication between the Service Capability Server (SCS) and the Machine Type Communication Interworking Function (MTC-IWF) within the 3GPP network, specifically for Machine-Type Communication (MTC) services. The Tsp interface enables the SCS, which manages MTC applications, to interact with the MTC-IWF to perform actions like device triggers, message forwarding, and notifications within the network.

The Tsp interface connects the SCS and MTC-IWF, allowing for the secure and efficient exchange of signaling messages related to MTC services. The SCS is responsible for handling MTC applications, enabling them to communicate with the 3GPP network through the MTC-IWF. The MTC-IWF acts as an intermediary that translates and forwards commands from the SCS to the appropriate network elements, ensuring that the MTC services are executed as intended.
Key functional elements:

• Service Capability Server (SCS): The SCS is the interface between MTC applications and the 3GPP network. It facilitates the initiation of service requests and actions related to MTC devices and applications. The SCS can connect to multiple MTC-IWFs, and it is controlled by the HPLMN operator or an MTC service provider.
• MTC Interworking Function (MTC-IWF): The MTC-IWF resides within the HPLMN and handles communications between the SCS and the network. It supports multiple interfaces, including Tsp, S6m, T4, and others, to provide functions such as device triggering, session management, and secure communication.

Tsp interface workflow:

1. Session Initialization: The SCS initiates a connection to the MTC-IWF over the Tsp interface to perform actions related to MTC services, such as sending a device trigger or managing notifications.
2. Request Handling: Upon receiving a request from the SCS, the MTC-IWF processes the command. This could involve triggering a device, forwarding a message, or executing other MTC-related actions within the network.
3. The MTC-IWF may need to interact with other network elements, such as the HSS, to retrieve necessary information or to complete the requested action.
4. Command Execution: The MTC-IWF executes the command received over the Tsp interface. For instance, it might send a device trigger request to a connected device or forward a notification back to the SCS about the status of the action.
5. The execution of these commands is based on the Diameter base protocol, ensuring reliable communication and processing.
6. Notification and Response: After executing the command, the MTC-IWF sends a response back to the SCS, notifying it of the outcome. This could include success, failure, or additional information related to the request.
7. The notification is sent using Diameter messages that are securely transported over the Tsp interface.
8. Session Termination: Once the transaction is complete, the session between the SCS and MTC-IWF is implicitly terminated. The Tsp interface does not maintain session state information beyond the completion of the current transaction, ensuring efficient resource usage.

For complete technical specification of Tsp interface in Diameter protocol please refer to: [3GPP TS 29.368]