26.5013GPP5G Media Streaming (5GMS)General description and architectureRelease 18TS
The 5GMS architecture offers the option to create aContent Hosting Configuration for external 5GMSd AS(s) through a provisioning interface, as described in clause 5.4. A Content Hosting Configuration is a 5GMS-optimized configuration that is tailored to a third-party content or service provider to leverage the capabilities of the 5G System to achieve optimized delivery of media content.
Upon successful setup of a Content Hosting Configuration, the 5GMSd AF uses the NSaaS to create or use an existing corresponding network slice, and assigns the Content Hosting Configuration domain as the network slice selection assistance information rule. This allows any traffic to and from the Content Hosting Configuration domain to be mapped to the correct network slice instance.
The concept of Network Slice as a Service (NSaaS) is defined in TS 28.530 . NSaaS can be offered by an MNO to third-party providers in the form of a service. This service allows the providers to use the network slice instance as the end user and to manage the network slice instance via a management interface exposed by the MNO. In turn, these providers offer their own services, e.g. OTT service, on top of the network slice instance obtained from the MNO.
The NSaaS offered by the MNO can be characterized by certain properties (capabilities to satisfy service level requirements), e.g.
– radio access technology,
– end-to-end latency,
– guaranteed / non-guaranteed QoS,
– security level, etc.
The interface that is used for the creation and management of network slices is defined in TS 28.531  and the information elements are defined in TS 28.541 .
The network (HPLMN) may provision the UE with Network Slice Selection Policy (NSSP) as part of the UE Route Selection Policy rules as described in TS 23.503 . This ensures that the UE will request a particular network slice when establishing the PDU session. Note that this mapping can also be established through associating an Application with the Content Hosting Configuration and the network slice, which in turn will be associated with a PDU session that includes the Content Hosting Configuration domain as a matching domain.
Once the PDU session is established using the network slice instance that corresponds to the Content Hosting Configuration, the media distribution to the UE may start. The network slice instance may be provisioned to support processing and edge computing in addition to the appropriate QoS allocation. The 5GMSd AF is responsible for ensuring appropriate traffic routing, e.g. request the routing of traffic to a local access to a Data Network (identified by a DNAI) that hosts the media processing compute instances.