Inter-frequency LTE-D Discovery via Base Station Relay

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Solution Overview

Problem

In Long Term Evolution (LTE) communication systems, user equipment (UE) in one cell operating at a first frequency needs to constantly monitor communication on a second frequency to discover UEs in another cell, which is inefficient and undesirable.

Innovation Solution

The UE receives discovery information from the base station on the first frequency, including discovery resource information, radio parameters, and timing reference information, allowing it to discover UEs in a second cell without constantly monitoring the second frequency, using system information blocks (SIBs) or RRC dedicated signaling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the UE constantly monitors communication on the second frequency to discover UEs in another cell, then the discovery reliability is improved, but the power consumption increases and resource utilization deteriorates

Engineering Contradiction:
Improvediscovery reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The base station performs preliminary actions by collecting discovery information from other base stations and proactively sending it to the UE through system information blocks or dedicated signaling. This allows the UE to discover UEs in neighboring cells without having to constantly monitor those frequencies, thereby reducing power consumption while maintaining discovery reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The base station acts as an intermediary that gathers discovery information from neighboring base stations and delivers it to the UE. Instead of the UE directly monitoring multiple frequencies, the base station mediates the information flow, providing discovery data through the serving cell's frequency, thus reducing the UE's monitoring burden and power consumption.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the UE constantly monitors communication on the second frequency to discover UEs in another cell, then the discovery completeness is improved, but the resource utilization deteriorates

Engineering Contradiction:
Improvediscovery completenessVSAvoidresource utilization
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The base station performs preliminary actions by collecting discovery information from other base stations and proactively sending it to the UE through system information blocks or dedicated signaling. This allows the UE to discover UEs in neighboring cells without having to constantly monitor those frequencies, thereby reducing power consumption while maintaining discovery reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The base station acts as an intermediary that gathers discovery information from neighboring base stations and delivers it to the UE. Instead of the UE directly monitoring multiple frequencies, the base station mediates the information flow, providing discovery data through the serving cell's frequency, thus reducing the UE's monitoring burden and power consumption.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3281426B1Inter-frequency LTE-d discovery
Publication Date: 2022.08.17 QUALCOMM INC
  • EP3281426B1 patent drawingFigure 1
  • EP3281426B1 patent drawingFigure 2A~2D
  • EP3281426B1 patent drawingFigure 3

AI summary

When a UE in a first cell operating at a first frequency attempts to discover another UE in a second cell operating at a second frequency, the UE in the first cell may need to constantly monitor communication on the second frequency to discover the UE in the second cell, which may not be desirable. According to an aspect of the disclosure, the apparatus receives, on a first frequency of a first channel from a first base station serving a first cell, discovery information associated with a second frequency of a second channel corresponding to a second cell, wherein the first frequency is a downlink (DL) frequency and the second frequency is an uplink (UL) frequency. The apparatus discovers, based on the received discovery information, one or more UEs on the second frequency of the second channel.