ETSI TS 129 305 is to specify the InterWorking Functions (IWF)

• between MAP-based Gr, Gf interfaces and Diameter-based S6a, S6d, S13, S13a interfaces;
• between the S6a interface with SMS subscription data on the MME side and the S6a interface without SMS subscription data plus the MAP-based D interface for SMS subscription on the HSS side;
• between MAP-based C for SMS interface and Diameter-based S6c interface;
• between MAP-based E for SMS interface and Diameter-based SGd interface.

The InterWorking Function between the S6a interface with SMS subscription data and the S6a interface without SMS subscription data plus the MAP-based D interface for SMS subscription (S6a/S6a+D) is described in Annex A.

The InterWorking Function between MAP-based C for SMS interface and Diameter-based S6c interface is described in Annex A.3.

The InterWorking Function between MAP-based E for SMS interface and Diameter-based SGd interface is described in Annex A.2.

For each IWF scenario, the present document will specify the mapping of related procedures and the corresponding parameter handling.

The present document will also specify the related mechanisms for the IWF, e.g. message routing, user data handling.

The other mechanism, such as security, will also be described in this document as a part of the whole solution.

If there is no specific indication, the SGSN in the specification refers to a S4-SGSN which supports S4 interface.