The SEALDD layer provides a general functionality to support data storage and data delivery by introducing 5G interaction (N5/N33 in control plane, N6 in user plane), including application data storage and management, application signalling and data transmission, E2E URLCC transmission, IoT message transmission (i.e. MSGin5G), etc.

For media delivery functionality in SEALDD, as shown in Figure D.2-1, the functionality/protocol defined in SA4 can be reused and further enhanced by SEALDD for supporting media type traffic, 5GMS/RTC AF and 5GMS RTC AS in TS 26.501 and TS 26.506 is utilized in SEALDD server to support the general media type delivery. The 5G transmission adaptation component is added in SEALDD, to facilitate the specific optimization for XR application provided by 5G network. NOTE: The functionality about 5G transmission adaptation component for media type will be further detailed based on the other progresses (e.g. application enabler for XR Services).

When utilizing the SEALDD to deliver the media stream, the SEALDD server integrates the 5GMS/RTC AF and 5GMS/RTC AS, the SEALDD client integrates as the media session handler and the media player/framework, and follows the support the uplink media transmission and the downlink media transmission defined in TS 26.501 and TS 26.506. The SEALDD-UU integrates the M4 and M5 interfaces of 5GMS according to TS 26.501, and the RTC-4 and RTC-5 interfaces of 5G RTC system according to TS 26.506. The SEALDD-S integrates the M1 and M2 interfaces of 5GMS according to TS 26.501, and the RTC-1 interface of 5G RTC system according to TS 26.506.