Description
Energy Savings Management (ESM) is a comprehensive framework within the 3GPP specifications, primarily falling under the domain of Operations, Administration, and Maintenance (OAM). It provides standardized mechanisms for network operators to implement energy-saving features across the Radio Access Network (RAN) and potentially other network domains. The core philosophy of ESM is to dynamically align network resource usage with traffic demand, thereby reducing energy consumption during periods of low load without significantly impacting the Quality of Service (QoS) experienced by users.
Architecturally, ESM functions are implemented within the Network Management (NM) and Element Management (EM) layers, as defined in the 3GPP Management Architecture (TS 28.628, TS 32.522). Key entities include the Energy Saving Management Function (ESMF), which is responsible for centralized energy-saving control and coordination. The ESM framework defines a control loop involving monitoring, analysis, decision, and execution phases. It collects energy-related performance measurements (PM) and configuration data from network elements like gNBs, ng-eNBs, and eNBs. Based on this data and operator policies, the ESMF can activate, deactivate, or adjust various Energy Saving (ES) actions on specific network elements or groups of elements.
These ES actions are the technical mechanisms that realize energy savings. They are extensively detailed in RAN specifications (e.g., TS 36.927, TS 38.927). Common actions include: putting carrier components into a dormant state where most RF components are powered down; switching off entire cells or sectors (Cell Switch Off); adjusting antenna tilt or power to reduce coverage area during low load; and implementing sophisticated symbol-level or slot-level switching in the time domain, where parts of the base station are powered down during empty or low-activity time slots. A critical aspect of ESM is the management of trade-offs. The framework includes concepts like Energy Saving State (ESS), which defines the level of energy-saving activity (e.g., 'not active', 'active with QoS maintained', 'active with QoS degraded'), and Compensation Neighbor Relations, which are pre-configured to ensure coverage is maintained by neighboring cells when a cell is switched off. The ESM procedures ensure these actions are coordinated to avoid coverage holes or service degradation.
Purpose & Motivation
ESM was created in response to the rapidly growing energy consumption and operational costs of mobile networks, driven by increasing data traffic and network densification. Prior to its standardization, energy-saving features were vendor-proprietary, making multi-vendor network management complex and limiting the operator's ability to implement cohesive, network-wide energy policies. The lack of standardization also hindered the development of advanced, coordinated savings mechanisms that require interoperability between network elements from different vendors.
The primary purpose of ESM is to provide a standardized, vendor-neutral framework that allows operators to effectively reduce their network's Power Consumption (PC) and Carbon Footprint (CF), which are key Performance Indicators (KPIs) for modern sustainable networks. It addresses the problem of inefficient static operation where network elements consume near-peak power regardless of actual traffic load. By enabling dynamic adaptation, ESM turns network energy consumption from a fixed cost into a variable one that scales with demand. Furthermore, it provides the management tools to control the inevitable trade-off between energy savings and network performance (coverage, capacity, QoS), allowing operators to implement savings strategies that align with their specific service level agreements and business objectives. Its introduction formalized energy efficiency as a first-class requirement in network management, on par with traditional KPIs like throughput and latency.
Classification
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (75 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.
Studied in Rel-8, normative work from Rel-15.
In Release 15, the ESM function was enhanced to support coordination and interworking procedures with the 5G Session Management (5GSM) protocol. This included updates to manage EPS bearer contexts during inter-system changes and alignments on back-off timer handling for ESM cause values. The release also introduced clarifications for network-requested UE policy management procedures and context management due to service request rejections.
- Coordination between ESM and 5GSM TS 24.301CR3003
- Add SON for AAS deployment management description and attributes TS 28.628CR0016
- Alignment on ESM cause #66 on back-off timer handling TS 24.301CR2938
- ESM protocol impacts to support interworking with 5GS TS 24.301CR3103
- No operation code for UE policy management TS 24.501CR0112
- Correction to 5GSM/ESM coordination TS 24.501CR0164
+ 6 more changes
In Release 16, key enhancements for ESM included the introduction of procedures for the transfer of port management information containers, MAC addresses, and DS-TT residence time, primarily to support Ethernet-based connectivity and wireline access management. This release also added specific capabilities for exchanging these port management features during PDU session establishment and introduced corrections for handling ESM timers and QoS errors in abnormal cases. Furthermore, it defined management mechanisms for service area and forbidden area restrictions in wireline access scenarios.
- Signalling of UE support for transfer of port management information containers, MAC address and DS-TT residence time TS 24.501CR1358
- Adding support for transfer of Ethernet port management information containers TS 24.501CR1359
- Port management information container: Delivery via the NAS protocol and coding TS 24.501CR1470
- Exchange of port management capabilities during PDU session establishment TS 24.501CR1693
- Correction on retry restriction for ESM#66 TS 24.301CR3363
- Correction to handling of ESM timers in abnormal cases TS 24.301CR3377
+ 14 more changes
In Release 17, specific enhancements were made to the EPS Session Management (ESM) protocol to improve the handling of non-congestion related back-off timers and UE retry restrictions. This included clarifications and corrections for the handling of the ESM non-congestion back-off timer during detach procedures and for specific ESM causes. Furthermore, updates were provided for session management aspects over non-3GPP access and for the port management information container.
- The impact on UE due to the introduction of Authentication and Key Management for Applications (AKMA) TS 24.501CR2794
- Clarify mobility management based on NSAC per access type independently TS 24.501CR3516
- Clarification of mobility management based NSAC for roaming case TS 24.501CR3515
- Update to session management based NSAC TS 24.501CR3468
- Clarify ESM non-congestion back-off timer handling for detach required TS 24.301CR3484
- Correction on UE retry restriction for ESM causes #50#51#57#58#61 TS 24.301CR3496
+ 10 more changes
In Release 18, ESM enhancements primarily introduced mechanisms for optimized handling of temporarily available network slices, including specific PDU session management procedures when the UE is outside a slice's area of support. The release also defined a new ESM cause for "User authentication or authorization failed" and refined the application of custom throttling to temporarily failed ESM procedures. Additionally, it strengthened congestion control integration by allowing UE unavailability period reporting to override mobility management congestion control in certain scenarios.
- Exchanging the SDNAEPC EAP message in ESM procedures TS 24.301CR3853
- UE unavailability period reporting for enhanced discontinuous coverage overrides mobility management congestion control - EPS TS 24.301CR3939
- Transport of messages of network-requested UE policy management procedure TS 24.301CR3934
- Mobility management for the support of optimised handling of temporarily available network slices TS 24.501CR5176
- Clarification about the condition of the PCF initiating the Network-requested UE policy management procedure TS 24.501CR5430
- Session management for optimized handling of temporarily available network slices TS 24.501CR5344
+ 13 more changes
In Release 19, the ESM function was enhanced to handle APN congestion control upon reception of an ESM DATA TRANSPORT message and to enable the sending of ESM TRANSPORT messages in EMM-IDLE mode with a suspend indication. Furthermore, procedures were clarified for using ESM STATUS messages to indicate invalid EPS bearer identities received via EMM TRANSPORT messages during the EMM data transport procedure. These updates refine session management interactions, particularly for congestion control and message transport in idle mode.
- Inclusion of ATSSS status in related session management messages TS 24.501CR6880
- NOTE regarding session management timer extension TS 24.301CR4080
- Handling of APN congestion control on reception of ESM data transport message TS 24.301CR4038
- Reception of ESM cause value is #50, #51 etc. during attach TS 24.301CR4203
- Sending ESM TRANSPORT Message in EMM-IDLE mode with suspend indiccation TS 24.301CR4239
- Correct T3451 management in timer table TS 24.301CR4487
+ 2 more changes
Explore further
Broader topics and technologies where ESM plays a role.
Defining Specifications
3GPP specifications that define or reference ESM, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 24.301 vj60 | NAS protocol for Evolved Packet System | Rel-19 |
| TS 24.305 vj00 | Selective Disabling of 3GPP UE Capabilities | Rel-19 |
| TS 24.501 vj50 | 5G NAS Protocols Specification | Rel-19 |
| TS 24.801 v810 | CT1 SAE NAS Aspects for EPC | Rel-8 |
| TS 24.890 vg00 | 5G NAS Protocol for 5GS Stage 3 | Rel-16 |
| TS 28.628 vj00 | SON Policy NRM IRP Information Service | Rel-19 |
| TS 29.272 vj40 | Diameter Interfaces for MME/SGSN | Rel-19 |
| TS 32.522 vb70 | SON Policy NRM IRP Information Service | Rel-11 |
| TS 32.551 vj00 | Energy Savings Management Concepts and Requirements | Rel-19 |
| TS 32.826 va00 | Study on Energy Savings Management in LTE/SAE Networks | Rel-10 |
| TS 32.834 vb00 | Inter-RAT Energy Saving Management Study | Rel-11 |
| TS 36.401 vj00 | E-UTRAN Overall Architecture Description | Rel-19 |
| TS 36.509 vh40 | EPC Special UE Conformance Testing Functions | Rel-17 |
| TR 36.927 vj00 | Network Energy Saving for E-UTRAN | Rel-19 |