Scell Activation Control Using L1 On-Off Signaling

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Solution Overview

Problem

The existing Scell activation/deactivation mechanisms in LTE and NR CA systems are slow, leading to increased power consumption and inefficient Scell operation due to long activation delays, which can be exacerbated by frequent deactivation and reactivation.

Innovation Solution

Implementing Layer 1 (L1) on/off commands in addition to MAC CE-based higher layer signaling for Scell activation/deactivation, allowing more aggressive control of Scell procedures, such as PDCCH monitoring and PUCCH/SRS transmissions, to reduce activation times and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If MAC CE-based activation/deactivation commands are used for Scell management, then the control mechanism is standardized and reliable, but the activation and deactivation delays are slow leading to increased power consumption

Engineering Contradiction:
Improvecontrol mechanism reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent segments the Scell management control into two distinct signaling layers: MAC CE commands for activation/deactivation decisions and new physical layer (L1) commands for rapid execution control. This segmentation allows the system to maintain the reliability of MAC CE-based standardized control while introducing faster L1 signaling to reduce execution delays and power consumption.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces physical layer (L1) signaling as an intermediary between the MAC CE commands and the actual Scell activation/deactivation execution. The L1 commands act as a mediator that can rapidly trigger or prevent Scell activation, bridging the gap between the slower MAC CE decision-making and the need for fast execution, thereby reducing overall delay and power consumption.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If MAC CE-based commands are used for Scell activation/deactivation, then the signaling is standardized, but the response time and network efficiency are reduced

Engineering Contradiction:
Improvesignaling standardizationVSAvoidnetwork efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent divides the signaling function into two segments: MAC CE signaling for standardized activation/deactivation decisions and new physical layer (L1) signaling for rapid response control. This segmentation preserves the standardized nature of MAC CE commands while adding a faster L1 layer to improve network efficiency and response time.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic control capability through physical layer (L1) commands that can rapidly adjust Scell activation status based on current network conditions. This dynamic L1 signaling layer complements the standardized but slower MAC CE commands, enabling the system to respond quickly to changing conditions while maintaining standardized control procedures.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If frequent Scell activation/deactivation is performed using MAC CE commands, then the network can adapt to changing conditions, but the power consumption increases due to slow response delays

Engineering Contradiction:
Improvenetwork adaptabilityVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent introduces physical layer (L1) signaling as an intermediary that enables frequent and rapid Scell activation/deactivation without the power consumption penalty of repeated MAC CE exchanges. The L1 commands can quickly trigger activation or deactivation decisions, allowing the network to adapt frequently to changing conditions while minimizing the energy cost of signaling.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent enables preliminary preparation of Scell activation parameters and configurations through L1 signaling, allowing the network to pre-configure Scell parameters so that when activation is needed, the process can proceed rapidly without extensive negotiation, thereby reducing power consumption during frequent adaptation cycles.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4167517B1Scell management for ca
Publication Date: 2026.05.06 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP4167517B1 patent drawingFigure 1
  • EP4167517B1 patent drawingFigure 2
  • EP4167517B1 patent drawingFigure 3

AI summary

Methods and apparatuses are disclosed for secondary cell (Scell) management. In one embodiment, a wireless device is configured to receive a first command, via a Medium Access Control, MAC, layer signaling, the first command being an activation/deactivation command; perform a first set of actions for at least one Scell of one or more Scells based at least in part on the first command; receive a second command, via a physical downlink control channel, PDCCH, signaling on a primary cell, Pcell; and perform a second set of actions for the at least one Scell of the one or more Scells based at least in part on the second command, the first set of actions and the second set of actions including starting or stopping PDCCH monitoring for the at least one Scell. In one embodiment, a network node is configured to send the first command and the second command.