# 3GPP TR 26.942 Change Request - Solution for Media Application Server Energy Management

## Change Request Overview

**CR Number:** 0007 rev 6  
**Specification:** 3GPP TR 26.942 v19.0.0  
**Work Item:** FS_Energy_Ph2_MED  
**Category:** B (Addition of feature)  
**Release:** Rel-20

This CR proposes Solution #11 addressing Key Issue #5 (Media Application Server Energy management) by introducing a content steering mechanism based on energy characteristics for downlink media streaming service location selection.

## References Added

- **[88]** 3GPP TS 26.512: "5G Media Streaming (5GMS); Protocols"
- **[89]** ETSI TS 103 998: "Content Steering for DASH"

## Solution #11: Selection of Downlink Media Streaming Service Locations Driven by Content Steering Server Based on Energy Characteristics

### Key Issue Mapping (Clause 7.12.1)

Addresses KI#5 specifically:
- Exposing energy-related information from the network (via EIF) to media delivery systems
- Enabling 5GMS AS to modify ongoing media delivery sessions based on energy-related characteristics shared by the network via Energy Information AF instantiated in the 5GMSAF

### Functional Description (Clause 7.12.2)

**Core Concept:**
- Leverages existing content steering capabilities in MPEG-DASH and HLS (already supported in 5GMS from Rel-19 per TS 26.512 clause 10.3A.4)
- Extends steering server decision-making to include environmental impact considerations alongside traditional QoS criteria
- Utilizes network energy characteristics from EIF (Energy Information Function) to select delivery paths with lowest environmental impact

**Key Differentiator:**
- Compared to Solution #5, this approach adapts streaming sessions based on network environmental impact without affecting the UE or impacting the data plane
- Decision-making is implementation-dependent but could use metrics like kgCO₂e per Joule of energy supplying the AS
- Example use case: Content available on 2 Media 5GMSd AS service locations with different energy supply mixes; MNO adapts steering to maximize use of location with lower kgCO₂e per Joule

**Applicability:**
- Exclusively for downlink media streaming (as per TS 26.512 clause 10.3A.4)

### Collaboration Scenario (Clause 7.12.3)

**Requirements:**
- Energy information reporting from EIF and/or 5GMSd AS
- No energy information from UE required
- Downlink media streaming only

### Reference Architecture Mapping (Clause 7.12.4)

**Architecture Components:**

Based on TS 26.501 and TS 26.506, instantiating Solution #5 architecture with modifications:

1. **Energy Information AF** (instantiated within 5GMSd AF):
   - Subscribes to and consumes NF Energy Information from EIF (per TS 23.501 clause 5.51) with required granularities (e.g., per UE)
   - Subscribes to and consumes AS Energy Information from 5GMSd AS
   - Operates according to Energy Information Processing Configuration provisioned by 5GMSd Application Provider

2. **Key Architectural Differences from Other Solutions:**
   - Energy Information Collector NOT instantiated in 5GMSd Client (UE)
   - 5GMSd AF is the decision-making function for service location selection
   - Uses reference point M4d for communicating service modification recommendations via steering information
   - Energy characteristics assumed unchanged on UE side; selection relies solely on network-provided energy information

3. **Reference Points:**
   - E5 and Energy Information Collector not instantiated (not required)
   - M4d used for steering information communication

**Advantages:**
- No impact on UE
- Compatible with legacy devices
- Less efficient than solutions incorporating UE energy data, but broader applicability

### Energy-Related Information (Clause 7.12.5)

#### Overview (7.12.5.1)

**Objective:** Dynamically select 5GMSd AS service location with energy information aligned with 5GMSd Application Provider configuration

**Information Required:**
- Energy consumed from EIF and various 5GMSd AS instances
- Environmental cost of energy supply
- Network energy consumption related to specific 5GMSd AS service locations (since AS typically only report direct consumption)

**Relevant Granularities:**

1. **Per network slice and/or Data Network:** Aggregating energy consumed by all NFs and AS instances active in particular slice/DN
2. **Per service:** Aggregating energy consumed by all Application Data Flows sharing same Application ID, service characteristics in IP 5-tuple, or served from all 5GMSd AS service locations sharing same AS host name
3. **Per service location:** Aggregating Media AS Energy Reports from all (Edge) Media AS instances to which service location has been deployed
4. **Per media streaming session:** Aggregating energy consumed by all Application Data Flows associated with same media delivery session identifier

#### Energy Configuration (7.12.5.2)

*Editor's Note: Energy Information Configuration will be detailed in separate solution*

High-level baseline parameters describing 5GMSd Application Provider's operational constraints regarding collection, reporting, and exposure of energy-related information.

#### NF Energy Report (7.12.5.3)

**Source:** TS 29.566 clause 6.1

**Subscription Parameters:**
- Initial: Application ID only
- During session: Refined using Service Data Flow Description per Service Location

**Report Content:**
- Total energy consumption in joules (per TS 29.122 clause 5.3.2.3.20)
- Provided at requested granularity
- For specific timestamp

#### 5GMSd AS Energy Report (7.12.5.4)

**Subscription Parameters:**
- Initial: Application ID and Service Location Identifier
- During session: Fine-tuned using Service Data Flow Description (exchange between all UEs and particular Service Location)

**Report Content:**
- Energy consumed in joules at specified granularity
- Reports from currently used Service Location AND other available Service Locations
- Allows UE to be informed of Service Locations with better performance characteristics aligned with user mode requirements
- Uplink data volume not used in this solution

### Procedures (Clause 7.12.6)

**Procedure Overview:**
Combines content steering procedure (TS 26.512 clause 10.3A.4) with baseline energy information sharing procedure (clause 7.6.3.2 Solution #5), omitting Energy Information Collector interactions.

**Key Procedure Steps:**

**Step 0:** Provisioning
- 5GMSd Application Provider creates Provisioning Session and Content Hosting Configuration in 5GMSd AF
- Content Hosting Configuration declares multiple service locations in different Distribution Configurations eligible for content steering
- 5GMSd AF provides:
  - Endpoint of content steering service at M4d
  - Base URLs of provisioned 5GMSd AS service locations at M4d
  - Information included in Service Access Information advertised via M8d

**Step 1:** Energy Information Configuration
- 5GMS Application Provider provisions 5GMS AF via M1d
- Includes Provisioning Session resource and Energy Information exposure configuration for Energy Information AF
- Contains Application Identifier for filtering Energy information reports
- Flag indicating Energy Information Collector NOT instantiated in UE

**Steps 4a-4c:** Initial Content Steering Configuration
- **4a:** Energy Information AF processes NF and AS Energy Information reports (moved from step 10 in baseline; no UE interaction expected)
- **4b:** 5GMS AF makes content steering prioritization decision considering:
  - Load on available service locations
  - Energy-related information from step 4a
  - Configures selected service location with higher priority in steering instructions
- **4c:** 5GMSd AF provides content steering configuration via M3d to 5GMSd AS content steering service

**Steps 15-17:** Network Energy Reporting
- **15:** EIF submits Network Energy Information report to Energy Information AF via E12
- **16:** 5GMSd AS submits AS Energy Information report to Energy Information AF via E3
- **17:** Energy Information AF processes reports and provides to 5GMSd AF

**Steps 17a-17b:** Content Steering Update (replaces baseline steps 18-25)
- **17a:** 5GMSd AF makes content steering prioritization decision based on energy-related information
- **17b:** 5GMSd AF provides updated content steering configuration via M3d

**Steps 20, 20a, 20b:** Session-based Updates
- Similar to steps 4a-4c, repeated during media streaming session

**Steps 28a/28a bis:** Media Player Entry Conditioning
- 5GMSd AS conditions Media Player Entry to add content steering service endpoint (if not already added by Application Provider)

**Step 28b:** Steering Instruction Request
- Media Player requests steering instruction from content steering service
- No specific energy information in steering instructions themselves

**Step 29:** Service Operation Point Selection
- Media Stream Handler selects based on steering instruction

**Step 30/30bis:** Transport Session Establishment
- Media Player establishes new transport session at M4d for acquiring media from selected Service Location (per content steering instruction)

**Step 37/37bis:** Media Content Request
- Media Player requests media content from selected 5GMSd AS service location

### Gap Analysis (Clause 7.12.7)

**Identified Gaps in Rel-19 Specifications:**

1. **Step 0:** Ability for 5GMSd Application Provider to declare in Content Hosting Configuration that service locations are eligible for content steering

2. **Step 0:** Ability for 5GMSd AF to nominate endpoint address of content steering service instantiated in 5GMSd AS

3. **Step 1:** Ability to indicate Energy Information Collector NOT instantiated in UE

4. **Steps 4b, 20a:** Functionality for 5GMSd AF to make content steering decision incorporating energy-related information from Energy Information AF

5. **Steps 4c, 20b:** Ability for 5GMSd AF to provide content steering configuration to 5GMSd AS content steering service via M3d

6. **Steps 28a, 28a bis:** Functionality for 5GMSd AS to condition Media Player Entry to add content steering service endpoint address

*Editor's Note: Additional gap regarding "steering request" to be explained*

### Proposed Normative Changes (Clause 7.12.8)

#### Stage 2 Changes (7.12.8.1)

**New Stage 2 Specification for Energy Information AF:**

1. Provisioning capability via M1d based on energy-related information requirements (clause 7.12.5), with option to not instantiate Energy Information Collector
   - *Editor's Note: Specific provisioning requirements TBD*

2. Energy-related information reporting by 5GMSd AS via E3 supporting aggregations:
   - Per network slice (for 5GMSd Client access to 5GMSd AS at M4d)
   - Per Data Network (for 5GMSd Client access to 5GMSd AS at M4d)
   - Per 5GMSd AS Distribution Configuration (service location)
   - Per Application ID
   - Per media streaming session

**Changes to TS 26.501:**

1. Inclusion of content steering service in 5GMSd AS as part of Energy Information AF instantiation

2. Documentation of content steering based on energy-related information in Energy Information AF procedures (per clause 7.12.6), either:
   - Included in baseline procedural definition, OR
   - Documented in separate procedure in Annex A of TS 26.501, motivated by collaboration scenario (clause 7.12.3)

**Changes to TS 26.506:**

*Editor's Note: To be determined*

#### Stage 3 Changes (7.12.8.2)

**New Stage 3 Specification for Energy Information AF:**

1. Provisioning capability via M1d based on energy-related information requirements (clause 7.12.5), with option to not instantiate Energy Information Collector
   - *Editor's Note: Specific provisioning requirements TBD*

2. Energy-related information reporting by 5GMSd AS supporting same aggregations as Stage 2

**Changes to TS 26.510:**

1. New clauses specifying extensions to procedures and service-based interfaces at E1, E3, and E12 reference points pertaining to 5GMS, regarding additional energy-related information from 5GMS AS and EIF for media streaming sessions enabling steering servers to select AS based on environmental impact

2. **Step 1 (clause 7.12.6):** New Energy Information Exposure Configuration resource (clauses 5.2 and 8) identifying which applications fall within scope

3. **Content Hosting Configuration extensions** (clauses 5.2.8 and 8.8.3.1):
   - **Gap 1:** Boolean flag in DistributionConfiguration indicating eligibility for content steering participation
   - **Gap 2:** URL of content steering service endpoint at M4d nominated by 5GMSd AF and passed to 5GMSd Application Provider

**Changes to TS 26.512:**

Extensions (as needed) to procedures and service-based interfaces at M1d, E3, and M5d reference points, particularly regarding additional energy-related information from 5GMS AS for media streaming sessions

*Editor's Note: Specifics TBD*

**Changes to TS 26.113:**

*Editor's Note: To be determined*

### Summary (Clause 7.12.9)

**Candidate Solution Proposal:**

New mechanism enabling 5GMSd Application Providers to steer 5GMSd Client towards service location with lowest environmental impact based on:

1. **Collection of network energy-related characteristics** by MNO:
   - Information provided by EIF and 5GMSd AS to Energy Information AF (included in 5GMSd AF)

2. **Standardized interfaces** between 5GMSd AF and 5GMSd Application Provider:
   - Allows Application Provider to provision content steering mechanism with goal of reducing environmental impact of downlink media streaming

3. **Dynamic steering** by 5GMSd AS (acting as content steering server):
   - Uses energy information to steer 5GMSd Clients toward service locations with desired energy characteristics

**Benefits:**
- Optimizes energy efficiency of multimedia content delivery
- Contributes to reducing environmental footprint of media streaming services
- Applies to any 5GMSd Application Provider delivering content via 5GMSd System
- Integrates naturally into existing adaptive streaming architectures (MPEG-DASH, HLS)

**Implementation Characteristics:**
- No impact on UE (leverages existing adaptive streaming protocol mechanisms)
- No impact on data plane
- Service location selection achieved by prioritizing desired location in steering instructions
- Compatible with legacy devices

## Additional Changes

### Clause 7.1: Mapping of Solutions to Key Issues

Solution #11 added to table mapping, addressing KI#5 (Media Application Server Energy management).

### Clause 7.6.3.2: Baseline Procedures

Steps 10a to 10d added to baseline procedures (specific details not provided in change markings).