LTE-Direct Relay Discovery for Out-of-Coverage Devices

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Solution Overview

Problem

Wireless communication systems face service disruptions when mobile devices move out of the coverage area of a base station, leading to loss of connectivity.

Innovation Solution

Mobile devices can transition to a relay status, broadcasting a peer discovery signal to indicate their capability to act as a relay between other mobile devices and a base station, establishing direct links to maintain communication even when out of coverage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mobile device transitions to relay status and transmits peer discovery signals continuously, then relay service availability is improved, but power consumption increases

Engineering Contradiction:
Improverelay service availabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The mobile device transmits peer discovery signals periodically at defined intervals rather than continuously, allowing the device to enter low-power states between transmission cycles while still maintaining relay service availability when needed

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The mobile device autonomously determines whether to transition to relay status by evaluating local conditions such as its own power level and the presence of out-of-coverage devices, making the relay service self-regulating and power-efficient

Inventive Principle:
Principle #25Self-service

2Reliability

If a mobile device transitions to relay status, then connectivity for out-of-coverage devices is improved, but device complexity increases

Engineering Contradiction:
ImproveconnectivityVSAvoidrelay functionality
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The mobile device acts as an intermediary relay node between out-of-coverage devices and the base station, using standardized peer discovery signals and relay protocols that simplify the complexity by providing a clear mediator role without requiring complex peer-to-peer negotiation

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The relay-capable mobile device can function in multiple modes (normal operation, relay status, out-of-coverage status) and the peer discovery signals are universally interpretable by any device in the network, reducing the need for device-specific complex logic

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

3Speed

If peer discovery signals are transmitted frequently, then relay discovery speed is improved, but transmission power increases

Engineering Contradiction:
Improverelay discovery speedVSAvoidtransmission power
Core Design Contradiction:
SpeedVSPower

Solution Approach 1:

Peer discovery signals are transmitted at periodic intervals rather than continuously or on-demand, achieving a balance between discovery speed and power consumption by using defined transmission cycles that allow quick discovery when needed while conserving power during idle periods

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The mobile device determines relay status and prepares peer discovery signals in advance based on predicted needs (such as detecting out-of-coverage conditions), allowing rapid relay establishment when required without continuous high-power transmission

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3028533B1Power efficient discovery of LTE-direct relay for out-of-coverage devices
Publication Date: 2021.09.08 QUALCOMM INC
  • EP3028533B1 patent drawingFigure 1
  • EP3028533B1 patent drawingFigure 2
  • EP3028533B1 patent drawingFigure 3A

AI summary

Methods, systems, and devices are described for managing wireless communications. In one method, a mobile device may determine to transition to a relay status. The relay status may indicate a capability of the mobile device to function as a relay device between at least one other mobile device and a base station. A peer discovery signal that indicates the relay status may then be transmitted. In another method, a mobile device may broadcast an out-of-coverage status indicator in a first peer discovery signal. A second peer discovery signal may be received from at least one other mobile device. The second peer discovery signal may indicate a capability of the at least one other mobile device to function as a relay device.