PDCCH-Triggered Random Access for Robust Cell Handover

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing wireless communication systems face challenges in ensuring robust and efficient handover procedures, particularly due to issues with decoding Physical Downlink Control Channels (PDCCH) during handovers, leading to potential radio link failures and interruptions in user experience.

Innovation Solution

Implementing a Physical Downlink Control Channel (PDCCH) order to trigger a random access procedure using dedicated preambles, ensuring synchronization and minimizing interruptions by utilizing PDCCH's robust link budget, and potentially combining it with Physical Downlink Shared Channel (PDSCH) commands for enhanced mobility management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional handover procedures are used, then the system operates with existing protocols, but PDCCH decoding failures occur leading to radio link failures and service interruptions

Engineering Contradiction:

Improvehandover reliabilityVSAvoidPDCCH decoding failures

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a dedicated random access procedure as an intermediary mechanism between the PDCCH command reception and successful handover completion. This dedicated procedure acts as a mediator that verifies the legitimacy of handover commands and ensures reliable connection establishment, preventing radio link failures caused by PDCCH decoding errors.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements preliminary verification through integrity checks on PDCCH commands before executing handover. The user equipment performs validation of received commands using dedicated random access procedures, ensuring that only authenticated and valid handover commands are executed, thereby preventing failures from erroneous decoding.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If standard random access procedures are used, then the process follows conventional protocols, but service interruptions and delays occur during handover

Engineering Contradiction:

Improvehandover speedVSAvoidhandover interruption time

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The patent employs a dedicated preamble for random access that is specifically allocated for handover purposes. This dedicated resource enables rapid and direct communication during handover without the need for extensive contention resolution procedures, significantly reducing handover interruption time and improving transition speed.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Ease of operation

If PDCCH commands are decoded without verification, then the process is simple and fast, but decoding errors lead to radio link failures

Engineering Contradiction:

Improvedecoding simplicityVSAvoidconnection stability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the user equipment sends a random access request after receiving the PDCCH command, and the network responds with a random access response. This feedback loop allows verification of command legitimacy and ensures proper handover execution, maintaining connection stability while adding minimal complexity to the decoding process.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12610300B2Method, apparatus and computer program

Publication Date: 2026.04.21 NOKIA TECHNOLOGIES OY

AI summary

There is provided a user equipment including at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the user equipment at least to: receive, from a source cell entity, a physical downlink control channel command; and based on the physical downlink control channel command, initiate a random access procedure to one or more target cells.