Uplink Mobility Handover Without Downlink Zone Signals

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Solution Overview

Problem

Existing wireless communication systems face challenges in supporting uplink-based mobility without the use of downlink zone signals, leading to inefficient resource utilization and increased energy expenditure for UE searching and measuring zone signals.

Innovation Solution

Implementing uplink-based mobility by using synchronization signals associated with serving or non-serving TRPs, along with keep-alive messages that include synchronization and power control information for uplink chirp signals, thereby eliminating the need for downlink zone reference signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If downlink zone signals are used for uplink-based mobility, then UE can perform synchronization and measurements, but resource utilization becomes inefficient and energy expenditure increases

Engineering Contradiction:
Improvemobility supportVSAvoidenergy expenditure for searching and measuring zone signals
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent extracts and removes the downlink zone reference signals from the system. Instead of using dedicated downlink zone signals for uplink-based mobility, the invention utilizes existing uplink signals (chirp signals) and downlink keep-alive messages, eliminating the need for separate zone signal transmission while maintaining mobility functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent makes existing signals serve multiple functions. Downlink keep-alive messages not only maintain connection state but also provide synchronization information for mobility. Uplink chirp signals serve both random access and zone identification purposes, eliminating the need for dedicated zone signals.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If downlink zone reference signals are transmitted, then UE can perform zone synchronization, but resource consumption increases

Engineering Contradiction:
Improvezone synchronizationVSAvoidresource consumption
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent makes existing signals serve multiple functions. Downlink keep-alive messages not only maintain connection state but also provide synchronization information for mobility. Uplink chirp signals serve both random access and zone identification purposes, eliminating the need for dedicated zone signals.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent extracts and removes the downlink zone reference signals from the system. Instead of using dedicated downlink zone signals for uplink-based mobility, the invention utilizes existing uplink signals (chirp signals) and downlink keep-alive messages, eliminating the need for separate zone signal transmission while maintaining mobility functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If zone signals are used for handover procedures, then mobility management is achieved, but communication procedures become complex

Engineering Contradiction:
Improvehandover managementVSAvoidcommunication procedures
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and removes the downlink zone reference signals from the system. Instead of using dedicated downlink zone signals for uplink-based mobility, the invention utilizes existing uplink signals (chirp signals) and downlink keep-alive messages, eliminating the need for separate zone signal transmission while maintaining mobility functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3520544B1Uplink-based mobility without downlink zone signals
Publication Date: 2026.04.15 QUALCOMM INC
  • EP3520544B1 patent drawingFigure 1
  • EP3520544B1 patent drawingFigure 2
  • EP3520544B1 patent drawingFigure 3

AI summary

Certain aspects of the present disclosure provide techniques for supporting UL-based mobility without DL zone signals. A DL zone signal may refer to a zone synchronization signal or a zone measurement reference signal. As described herein, a UE may perform certain operations upon power-up or RLF recovery, perform operations in each DRx cycle, and/or perform inter-zone handovers without relying on DL zone signals. Thus, aspects create a more user-centric environment and reduce and/or avoid transmission DL zone signals.