Change Request Summary: Media Service Level Degradation Based on Accumulated Energy Consumption

Document Information

• CR Number: 0012 rev 4
• Specification: TS 26.942 v19.0.0
• Work Item: FS_Energy_Ph2_MED
• Category: B (addition of feature)
• Release: Rel-20

Purpose

This CR proposes a solution for Key Issue 4 (Energy-related configuration by ASP) and Key Issue 6 (Client-driven management of media delivery service energy optimization) by introducing energy event-driven media service level degradation based on accumulated energy consumption.

Main Technical Contributions

1. Energy Policy Framework

1.1 Core Concept

• Introduces Energy Policies - UE-specific energy-related policies provisioned by the Media Application Provider in the Energy Information AF
• Each Energy Policy defines:
• Energy accounting period: Duration over which network energy consumption is monitored and accumulated
• Energy Segments: Ordered list of quotas representing contiguous intervals of cumulative energy consumption
• Each segment defined by lower/upper energy thresholds
• Each segment mapped to specific service performance levels (QoS parameters or Service Operating Points)

1.2 Energy Policy Parameters

Key information elements include:
- External reference: Unique identifier for UE Media Client selection
- Names/Descriptions: Multilingual human-readable information
- Granularity: Scope of energy measurement (per-UE, per-PDU session, per-QoS flow, per-slice, or AS)
- Accounting period: Time period for continuous energy monitoring (e.g., session, hour, day)
- Client subscription permissions: Flag for Energy-driven Service Level Change Event notifications
- Energy segments: List of segments with:
- Segment range (lower/upper thresholds)
- Applicable QoS parameters (e.g., degraded bit rate)
- Applicable Policy Template identifier (optional)
- AS Energy Policy parameters (optional, for AS granularity)

1.3 Multiple Policy Support

• Multiple Energy Policies can be provisioned with the same accounting period
• Allows ASP to offer UEs choice between different service performance constraints
• All policies reflect same current/predicted energy-related characteristics of serving network

2. Service Level Change Notification Mechanism

2.1 Energy Segment Transitions

• Energy Information AF continuously monitors and tracks cumulative energy consumed by UE
• When accumulated energy crosses Energy Segment boundaries, service performance level changes
• Energy Information AF triggers degradation/improvement based on segment mapping

2.2 Energy-driven Service Level Change Events

New event type containing:
- Current Energy Segment status: Details of currently applied segment (unit, current usage, range)
- Undegraded Policy Template/bit rate: Performance achievable if energy situation improves
- Energy-degraded Policy Template/bit rate: Current degraded performance due to energy impacts
- Predicted duration/end time: Optional timing information for degradation
- Scope of degradation: Indicates whether degradation applies to UE/user, cells, service location, or network
- Degradation cause: Network-to-device transmission or server processing

2.3 Notification Flow

• Energy Information AF notifies Media AF of service level changes
• May trigger Dynamic Policy changes for the media delivery session
• Events delivered to Energy Information Collector in UE Media Client
• Media Client receives actionable information for adaptation decisions

3. Client Adaptation Mechanisms

3.1 UE Response Options

Upon receiving Energy-driven Service Level Change Event, Media Client can:
1. Continue with degradation: Adapt media delivery to stay within degraded service level
2. Upgrade service level: Spend energy credits or purchase mechanism
3. Re-select Energy Policy: Change to different policy (e.g., from "green" to "less green")
4. Other actions: Including session termination

3.2 Informed Decision Making

• UE can distinguish energy-driven degradation from congestion or connection issues
• Additional context (scope, cause, duration) enables intelligent adaptation
• Autonomy preserved for client-side decision making

4. Architecture and Reference Points

4.1 Key Components

• Energy Information AF: Instantiated in Media AF
• Provisions and manages Energy Policies
• Monitors accumulated energy consumption
• Generates Service Level Change Events
• Interfaces with EIF and Media AS
• Energy Information Collector: Instantiated in Media Session Handler
• Receives Energy Policies from Energy Information AF
• Subscribes to Service Level Change Events
• Exposes information to Media Client

4.2 Reference Points

• M1: Energy Policy provisioning by ASP to Media AF
• E5: Energy Policy configuration, instantiation, and event delivery between Energy Information AF and Collector
• E12: NF Energy Information reporting from EIF to Energy Information AF
• E3: AS Energy Information reporting from Media AS to Energy Information AF
• M6: Energy Policy Status and Service Level Change Event exposure to Media-Aware Application
• M5: Dynamic Policy change notifications (optional)
• N5: PCF policy control for QoS modification (optional)

5. Detailed Procedures

5.1 Provisioning Phase (Steps 1-4)

1. ASP provisions Media AF with Energy Policy provisioning resource and Energy Information exposure configuration
2. Energy Information AF subscribes to NF Energy Information from EIF
3. Energy Information AF configures Media AS
4. Energy Information AF subscribes to AS Energy Information from Media AS

5.2 Session Initiation Phase (Steps 5-15)

1. Media-Aware Application initiates session with energy collection and Energy Policy features enabled
2. Media Session Handler obtains Service Access Information including Energy Policy configuration
3. Media Session Handler creates energy collection context in Energy Information Collector
4. Energy Information Collector requests UE Energy Information collection configuration including Energy Policies
5. Energy Information Collector subscribes to Service Level Change Events
6. Energy Information AF processes energy reports and identifies initial energy segment
7. Initial Energy Policy Status report delivered to Energy Information Collector
   12-15. Energy Policy Status information propagated to Media-Aware Application

5.3 Media Delivery Phase (Steps 16-21)

16-17. Media-Aware Application selects Media Entry Point based on Energy Policy Status
18-19. Media Stream Handler establishes transport and requests Media Entry Point
20-24. Optional Service Operation Point selection and Service Data Flow updates
25. Media delivered between Media Stream Handler and Media AS

5.4 Runtime Monitoring Phase (Steps 29-37)

29-30. EIF and Media AS expose energy information reports to Energy Information AF
31. Energy Information AF processes reports, checks Energy Policy, detects segment changes
31a-d. Optional Dynamic Policy change triggered and Service Level Change Event generated
32. Network Energy Information report with Energy Policy status exposed to Energy Information Collector
35-36. Service Level Change Events shared with Media Session Handler and Media-Aware Application
37a-d. UE decides on energy-degradation response, results reported back through chain

6. Gap Analysis

6.1 Dependencies

• Based on Network Energy Information from EIF
• Builds on baseline Solution #5 (Energy Information AF and Collector entities)

6.2 New Capabilities Required

• Energy Policy provisioning via M1
• Energy Policy delivery and configuration via E5
• Energy Policy selection and instantiation by Media Session Handler
• Energy-driven Service Level Change Event subscription and delivery
• Energy Policy Status exposure to Media Client
• Dynamic Policy triggering based on segment changes
• Energy-degradation response handling

7. Normative Requirements

7.1 Stage 2 Specifications

• Generic architecture and procedures for Energy Information AF/Collector
• Energy Policy provisioning, exposure, configuration, and instantiation operations
• Service Level Change Event subscription and exposure mechanisms

7.2 Stage 3 Specifications

• Network APIs for reference points E1, E3, E5
• Energy Policy provisioning API and resources
• Energy Policy configuration in UE Energy Information Collection
• Resource update notification channel for events

7.3 5GMS-Specific Extensions (TS 26.501, TS 26.510, TS 26.512)

• Energy Policy provisioning by 5GMS Application Provider
• Energy Policy usage for monitoring and triggering events
• Dynamic Policy change triggering
• Service Level Change Event creation and exposure
• M1 extensions for Energy Policy provisioning API
• M5 extensions for Energy Policy in Service Access Information
• M6 extensions for Energy Policy Status and event exposure
• MQTT notification channel extensions

7.4 RTC-Specific Extensions (TS 26.506, TS 26.113)

• Equivalent procedures for RTC functions
• RTC AF instantiation of Energy Information AF
• RTC-specific collaboration scenarios

Key Changes from Previous Revisions

• Terminology refinement: "Energy subscription period" → "Energy accounting period"
• Enhanced Energy Policy Status reporting in procedures
• Clarified Energy Segment transition detection logic
• Expanded energy-degradation response reporting flow (steps 37a-d)
• Refined normative requirements structure