Lower-Layer Cell Switching With Selective L2 Procedure Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing lower-layer based mobility procedures in cellular communication suffer from unpredictable UE trace and unclear configuration of L2 procedures during cell switch, leading to increased latency, overhead, and interruption time.

Innovation Solution

A method where a network device transmits information associated with a lower-layer signaling based cell switch, enabling the terminal device to determine whether to perform specific L2 procedures such as PDCP recovery, PDCP SDU discard, RLC re-establishment, or MAC reset, and the terminal device sends a completion indication to the network device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If lower-layer signaling is used to trigger cell switch, then latency and interruption time are reduced, but the configuration of L2 procedures becomes unclear and UE trace becomes unpredictable

Engineering Contradiction:

Improvelatency and interruption timeVSAvoidconfiguration clarity and trace predictability

Core Design Contradiction:

Loss of timeVSLoss of information

Solution Approach 1:

The patent introduces feedback mechanisms where the UE reports its trace information and the network device provides feedback on the configuration status. This allows the network to maintain predictability and control over L2 procedure configurations while using lower-layer signaling for fast cell switching, resolving the contradiction between speed and configurability.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent applies preliminary action by pre-configuring L2 procedure parameters and trace reporting mechanisms before the cell switch occurs. This ensures that even though lower-layer signaling is used for rapid switching, the necessary configuration information is already in place, maintaining predictability without sacrificing latency reduction.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If multiple L2 procedures are performed during cell switch, then reliability is improved, but overhead and processing complexity increase

Engineering Contradiction:

Improvecell switch reliabilityVSAvoidprocedure configuration complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the L2 procedures into distinct, independently controllable components (PDCP recovery, PDCP SDU discard, RLC re-establishment, MAC reset). Each procedure can be selectively enabled or disabled based on specific conditions, reducing overall complexity while maintaining reliability through targeted procedure execution.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent makes the L2 procedure configuration dynamic by allowing the network to adaptively select which procedures to perform based on real-time conditions such as cell type, UE capability, and service requirements. This dynamic approach reduces unnecessary processing complexity while maintaining reliability when needed.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS20260040167A1Method, device and computer storage medium of communication

Publication Date: 2026.02.05 NEC CORP

AI summary

Embodiments of the present disclosure relate to methods, devices and computer readable media of communication. A terminal device receives information associated with a lower-layer signaling based cell switch and determines, based on the information, whether a set of procedures are performed during the lower-layer signaling based cell switch. The set of procedures comprises at least one of the following: a PDCP recovery for a set of DRBs; a PDCP SDU discard for a set of SRBs; a RRC re-establishment for a set of DRBs and a set of SRBs; or a MAC reset. In this way, a terminal device may determine whether to perform or skip some L2 procedures for subsequent lower-layer based mobility procedures.