Content for  TS 26.501  Word version:  19.0.0

From the network slicing architecture specification in TS 23.501, the following is inferred:

1. A UPF instance may be shared between multiple network slices.
2. Multiple PDU Sessions terminating in different Data Networks may share the same slice.
3. PDU Sessions in different network slice instances may terminate in the same Data Network.

Based on this, the following two collaborations are possible:

• Media streaming wherein content is delivered by/to a 5GMS AS through two different network slices.
• Media streaming wherein 5GMS AS instances deployed in different Trusted DNs are accessed by the 5GMS client in the same network slice.

This clause describes collaboration options based on the above two possibilities.

This collaboration scenario shown in Figure G.2.2-1 represents the case of accessing the same external Data Network through two different network slices. An external CDN (5GMS AS) is accessed by the UE via this Data Network.

The 5GMS Application Provider may negotiate with the MNO to setup two different network slices with different service level agreements (SLA). After the SLA negotiation, the operator may provision two network slices, and provide connectivity services to the external Data Network through both the slices. The 5GMS Application Provider may deliver Service Access Information through reference point M8. The Service Access Information delivered to the 5GMS-Aware Application may have information about different Service Operation Points accessible through each of the network slices. Upon receiving the Service Access Information, the 5GMS-Aware Application passes this information to the 5GMS Client. The 5GMS Client selects the Service Operation Point of interest, and requests media streaming session establishment over the PDU Session in the network slice that provides the required Service Operation Point. Media streaming (M4) thus happens through the selected network slice. The other network slice may be used to fetch/contribute other media streaming assets (depending on criticality and SLA availability considerations), or serves as an alternate network slice in case the first slice becomes unavailable, as discussed in clause 6.3.

This collaboration scenario shown in Figure G.2.3-1 represents the case of accessing two different Data Networks using the same network slice. A CDN server (5GMS AS) is either deployed in each of the trusted Data Networks, or presents a multi-homed interface at reference point M4 through each of the trusted DNs.

The 5GMS Application Provider may negotiate with the MNO to provision a network slice. The operator provisions the network slice, and provides connectivity services to both the DNs through the slice. The 5GMS Application Provider may deliver Service Access Information through reference point M8. The Service Access Information delivered to the 5GMS-Aware Application may have information about different Service Operation Points accessible through each of the DNs. For example, an enterprise may use an enterprise-specific CDN (e.g., hosting enterprise-related video tutorials). 5G Media Streaming sessions for enterprise-related video tutorials use the PDU Session terminating in the enterprise-specific CDN, while some other video tutorial requests are sent through PDU Sessions terminating in a different CDN. Alternatively, a DN may act as a back-up CDN, utilised by the 5GMS Client if the primary CDN is inaccessible or unavailable for any reason. In a variant of this scenario, the second CDN may be a CDN edge with optional media processing. In another variation of the above scenario shown in Figure G.2.3-1, a common 5GMS AS may serve traffic via two trusted Data Networks down the separate PDU Sessions, as shown in Figure G.2.3-2.