Relay UE Sleep Mode for Pilot Pollution Reduction

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Solution Overview

Problem

A large number of activated relay UEs in a given area create 'pilot pollution,' reducing signal quality for terminal UEs and wasting battery life, as similar coverage can be achieved with fewer relays, leading to interference and inefficient battery consumption.

Innovation Solution

Implementing a sleep mode for relay UEs, where they measure and report signals from other relays during designated subframes, allowing the network to determine which relays to turn off, and adjusting transmission intervals based on serving status to reduce interference and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a large number of relay UEs are activated in a given area, then coverage area is expanded, but signal quality deteriorates due to pilot pollution and interference

Engineering Contradiction:
Improvecoverage areaVSAvoidsignal quality
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent implements periodic action by configuring relay UEs to operate in alternating subframe patterns - some subframes are designated for transmission while others are for measurement and sleep mode. This periodic activation and deactivation reduces continuous interference while maintaining coverage, as relays only transmit during their designated subframes rather than continuously

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies dynamics by making relay UE activation status changeable based on network conditions. The network can dynamically configure which relay UEs are active and which are in measurement mode, allowing the system to adapt the number of active relays to optimize signal quality while maintaining adequate coverage

Inventive Principle:
Principle #15Dynamics

2Area of stationary object

If a large number of relay UEs are activated in a given area, then coverage area is expanded, but battery life is wasted due to inefficient power consumption

Engineering Contradiction:
Improvecoverage areaVSAvoidbattery life
Core Design Contradiction:
Area of stationary objectVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic action by configuring relay UEs to operate in alternating subframe patterns - some subframes are designated for transmission while others are for measurement and sleep mode. This periodic activation and deactivation reduces continuous interference while maintaining coverage, as relays only transmit during their designated subframes rather than continuously

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies discarding and recovering by temporarily deactivating (discarding) relay UEs from active transmission duty during periods when their service is not needed, allowing them to enter low-power measurement modes. The network can recover and reactivate these relays when additional coverage or capacity is required, thus conserving battery life while maintaining coverage availability

Inventive Principle:
Principle #34Discarding and recovering

3Reliability

If relay UEs continuously transmit signals, then coverage is maintained, but interference among relay UEs increases

Engineering Contradiction:
Improvecoverage maintenanceVSAvoidinterference
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent implements periodic action by configuring relay UEs to operate in alternating subframe patterns - some subframes are designated for transmission while others are for measurement and sleep mode. This periodic activation and deactivation reduces continuous interference while maintaining coverage, as relays only transmit during their designated subframes rather than continuously

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies segmentation by dividing time into distinct subframe segments with different functions - transmission subframes where relays send signals, and measurement subframes where relays listen and report. This temporal segmentation separates conflicting transmission activities, reducing interference while ensuring coverage is maintained during transmission phases

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2735199B1Sleep mode for user equipment relays
Publication Date: 2019.08.21 QUALCOMM INC
  • EP2735199B1 patent drawingFigure 1~2
  • EP2735199B1 patent drawingFigure 3
  • EP2735199B1 patent drawingFigure 4

AI summary

Certain aspects of the present disclosure provide methods and apparatus for subframe muting and/or discontinuous reception (DRX) mode related to sleep mode for user equipment (UE) relays. One method generally includes measuring, at a UE functioning as a relay (i.e., a UE relay), signals of one or more other UEs functioning as relays during one or more particular subframes and reporting the measurements of the signals to an apparatus. Another method generally includes determining, at a first UE functioning as a relay, that no UEs are being served by the first UE; based on the determination, increasing an interval between broadcast signals; and transmitting the broadcast signals according to the increased interval.