notEnergySaving state

Description

The notEnergySaving state is a fundamental concept in 3GPP energy efficiency management, defined in specifications such as TS 28.310 (Energy Efficiency of 5G) and TS 32.551 (Energy Efficiency of 5G). It represents the baseline operational mode of a network function or network element when no energy saving features are engaged. In this state, the network operates at full capacity, prioritizing service availability and performance over energy consumption. This is the default state that a cell, gNB, or other managed entity assumes when energy saving policies are not actively reducing its capabilities.

Architecturally, the notEnergySaving state is one of several energy saving states defined within the 3GPP management framework. The Management Data Analytics Function (MDAF) and the Energy Saving Management (ESM) function within the Operations, Administration, and Maintenance (OAM) system monitor network load and trigger transitions between states. When traffic demand is high, the network remains in notEnergySaving state to ensure adequate quality of service. When traffic decreases, the network may transition to an energySaving state, where certain resources are deactivated or put into sleep mode. The notEnergySaving state thus serves as the reference point for measuring energy savings and for defining control policies.

The state is typically controlled through the Energy Saving Management (ESM) procedures. The OAM system configures energy saving policies that specify thresholds and conditions for entering and leaving the notEnergySaving state. For example, a policy might dictate that a cell enters energy saving when its load falls below a certain percentage for a specified duration, and returns to notEnergySaving when load exceeds another threshold. The state information is exchanged between network elements and the management system using protocols such as the Network Resource Model (NRM) and the Integration Reference Point (IRP) mechanisms.

In multi-RAT and multi-layer deployments, the notEnergySaving state is crucial for coordinating energy saving across different radio access technologies and frequency layers. For instance, when a 5G NR cell enters energy saving, it may offload traffic to LTE or to other NR carriers, which must be in notEnergySaving state to handle the additional load. The management system ensures that coverage and capacity requirements are met by keeping a sufficient set of cells in notEnergySaving state. This coordination prevents coverage holes and service degradation.

The notEnergySaving state also plays a role in the broader context of network slicing and QoS management. When energy saving is active, the network must ensure that service level agreements (SLAs) for different slices are still met. The notEnergySaving state provides a fallback to guarantee that critical services can be supported when energy saving would otherwise compromise them. As networks evolve towards higher automation, the transition between notEnergySaving and energySaving states is increasingly driven by AI/ML algorithms that predict traffic patterns and optimize energy consumption while maintaining performance.

Purpose & Motivation

The notEnergySaving state exists to provide a clear, standardized baseline for energy saving management in cellular networks. Before its introduction, energy saving mechanisms were vendor-specific and lacked a common framework for coordination and measurement. The 3GPP defined this state to enable interoperable energy saving features across multi-vendor networks, allowing operators to reduce operational expenditure (OPEX) by lowering energy consumption during low-traffic periods without sacrificing service quality during peak hours.

The concept addresses the growing need for energy efficiency in mobile networks, which contribute significantly to operational costs and environmental impact. By defining a default state where no energy saving is active, the standard ensures that network performance is not compromised when traffic demands are high. It also provides a reference for calculating energy savings: the difference between energy consumption in notEnergySaving state and energySaving state quantifies the benefit of energy saving features.

Furthermore, the notEnergySaving state facilitates coordination among different network functions and domains. It allows the management system to know when a network element is operating at full capacity, which is essential for load balancing, mobility management, and ensuring end-to-end service continuity. As networks become more complex with the introduction of 5G and beyond, the notEnergySaving state remains a cornerstone for automated energy saving solutions that balance efficiency with performance.