Layer 1/2 Mobility Random Access for Early Timing Alignment

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing wireless communication systems face challenges in efficiently managing layer 1 and layer 2 mobility, particularly in scenarios involving New Radio (NR) user planes, leading to suboptimal network performance and user experience.

Innovation Solution

Implementing a random access procedure that triggers layer 1 and layer 2 mobility, utilizing early time alignment acquisition and CSI reporting to enhance network connectivity and reduce latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional mobility management procedures are used in NR environments, then network compatibility is maintained, but network efficiency and user experience deteriorate due to suboptimal performance

Engineering Contradiction:

Improvenetwork efficiencyVSAvoiduser experience

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent changes the mobility management parameters by introducing layer 1 and layer 2 triggered mobility procedures that differ from traditional layer 3 handover. This includes new parameters for timing advance acquisition, CSI reporting configurations, and conditional handover triggers that optimize network efficiency and user experience in NR environments

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If layer 3 based handover is used, then mobility management is simplified, but latency increases and network connectivity is suboptimal

Engineering Contradiction:

Improvemobility management complexityVSAvoidhandover latency

Core Design Contradiction:

Device complexityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by performing timing advance acquisition and CSI reporting before the actual handover execution. The network configures conditional handover parameters in advance, and the UE prepares mobility measurements and reports beforehand, enabling faster handover execution and reducing overall latency

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent segments the handover procedure into distinct layer 1 and layer 2 triggered phases separate from traditional layer 3 handover. This segmentation allows independent optimization of different mobility aspects, reducing overall complexity while enabling lower latency through specialized handling of timing and measurement functions

Inventive Principle:

Principle #1Segmentation

3Reliability

If early time alignment acquisition and CSI reporting are implemented, then network connectivity and latency are improved, but procedure complexity increases

Engineering Contradiction:

Improvenetwork connectivityVSAvoidrandom access procedure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges early time alignment acquisition and CSI reporting into a unified random access procedure triggered by layer 1 and layer 2 events. This combination allows both functions to be performed together in a coordinated manner, improving network connectivity through better timing synchronization and channel state information while managing complexity through integrated processing

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS20250310971A1Random access procedure for layer 1 and 2 triggered mobility

Publication Date: 2025.10.02 OFINNO LLC

AI summary

A method comprises receiving, by a wireless device, a first physical downlink control channel (PDCCH) order initiating a random access procedure associated with early timing advance acquisition procedure of a layer 1 and/or 2 triggered mobility (LTM) procedure. The method further comprises, based on the first PDCCH order, setting a preamble power ramping counter (PPRC) to an initial value, and transmitting a first preamble via the first candidate cell, with a first power. The method further comprises receiving a second PDCCH order, and transmitting, with a second power determined based on increasing the PPRC by one, a second preamble via the first candidate cell, based on: a first field of the second PDCCH order indicating the first candidate cell and a second field of the second PDCCH order indicating a retransmission.