7.17 LI at 5GMS AF

33.1273GPPLawful Interception (LI) architecture and functionsRelease 18TS

7.17.1 Background

5G Media Streaming (5GMS) is a concept described in 3GPP TS 26.501 [53] and is defined as the delivery of time-continuous media as the predominant media. Streaming points to the fact that the media is predominantly sent only in a single direction and consumed as it is received. Additionally, the media content may be streamed as it is produced, referred to as live streaming. If media content being streamed is already produced, it is referred to as on-demand streaming.

The overall 5G Media Streaming Architecture is shown in Figure 4.1-2 of clause 4.1 of TS 26.501 [53].

7.17.2 Architecture

The 5GMS AF shall provide the IRI-POI function. Figure 7.17.2-1 gives a reference point representation of the LI architecture with 5GMS AF as a CP NF providing the IRI-POI function for 5G Media Streaming. A 5GMS AF that is edge-enabled shall support EES functionality. A UE may request edge processing for a streaming session from the EES embedded in the 5GMS AF. EES provides the IRI-POI function as specified in clause 7.16.

Figure 7.17.2-1: LI architecture for 5G Media Streaming showing LI at 5GMS AF

7.17.3 Target identities

The LIPF present in the ADMF provisions the intercept information associated with the following target identities to the IRI-POI present in the 5GMS AF:

– GPSI.

7.17.4 IRI events

The IRI-POI in the 5GMS AF shall generate xIRI when it detects the following specific events or information in both roaming and non-roaming situations:

– Service access information (see clause 4.2.3 of TS 26.501 [53]).

– Consumption reporting (see clause 5.6 of TS 26.501 [53]).

– Metrics reporting (see clause 5.5 of TS 26.501 [53]).

– Dynamic policy invocation (see clause 5.7 of TS 26.501 [53]).

– Network assistance (see clauses 5.9 and 6.5 of TS 26.501 [53]).

– Start of interception with already configured UE.

The service access information xIRI is generated when the IRI-POI present in the 5GMS AF detects that a 5GMS AF has sent service access information to the Media Session Handler in the target UE. Service access information consists of a set of parameters and addresses that are needed by a UE to activate the reception of a downlink media streaming session or the transmission on an uplink media streaming session, perform dynamic policy invocation, consumption reporting and/or metrics reporting, and request AF-based network assistance.

The consumption reporting xIRI is generated when the IRI-POI present in the 5GMS AF detects that the Media Session Handler in the target UE has reported downlink media consumption to the 5GMS AF.

The metrics reporting xIRI is generated when the IRI-POI present in the 5GMS AF detects that the Media Session Handler in the target UE has reported QoE metrics reports to the 5GMS AF.

The dynamic policy invocation xIRI is generated when the IRI-POI present in the 5GMS AF detects that a Media Session Handler in the target UE requests a specific policy and charging treatment to be applied to a particular application data flow of a downlink or uplink media streaming session to the 5GMS AF.

The network assistance xIRI is generated when the IRI-POI present in the 5GMS AF detects that the Media Session Handler in the target UE requests a bit rate recommendation from the 5GMS AF or requests a delivery boost during the ongoing media streaming session from the 5GMS AF.

The unsuccessfulProcedure xIRI is generated when the IRI-POI present in the 5GMS AF detects an unsuccessful procedure or error condition for the Media Session Handler in the target UE.

The start of interception with already configured UE xIRI is generated when the IRI-POI present in the 5GMS AF detects that interception is activated on the target UE that has already received the service access information for the configuration of its media streaming sessions from the 5GMS AF.