Relay Migration for Robust Ultra-Low-Power UE Wake-Up Signaling

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Solution Overview

Problem

Existing wake-up mechanisms for ultra-low-power UEs, such as IoT devices, are inefficient and unreliable, particularly in areas with poor RF links, leading to high energy consumption and potential misdetection, as they require direct communication with the base station for wake-up and data transfer.

Innovation Solution

Implementing relay migration and relayed group wake-up signaling, where ultra-low-power UEs communicate through relay nodes, optimizing synchronization and wake-up signals to minimize power consumption and ensure robust connectivity, even in non-coverage areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If direct wake-up signaling from base station to ultra-low-power UE is used, then the system maintains simple architecture, but energy consumption increases and reliability decreases in poor RF conditions

Engineering Contradiction:

Improvewake-up signaling reliabilityVSAvoidUE energy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent introduces relay UEs as intermediary nodes between the base station and ultra-low-power UEs. The relay UE receives wake-up signals from the base station and forwards them to the target UE, enabling reliable wake-up signaling in poor RF conditions without requiring the ultra-low-power UE to maintain direct connection with the base station, thus reducing its energy consumption.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The wake-up signaling process is segmented into multiple hops: base station to relay UE, and relay UE to target UE. This segmentation allows the signal to be transmitted through intermediate nodes with better RF conditions, improving overall reliability while allowing the ultra-low-power UE to remain in deep sleep mode longer, reducing its energy consumption.

Inventive Principle:

Principle #1Segmentation

2Reliability

If relay nodes are introduced for wake-up signaling, then energy consumption and reliability are improved, but system complexity increases

Engineering Contradiction:

Improvewake-up signaling reliabilityVSAvoidsystem architecture complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The relay UE autonomously performs wake-up signal forwarding without requiring complex network coordination. The relay UE monitors for wake-up signals intended for its associated ultra-low-power UEs and automatically forwards them, reducing the need for complex network-side relay management and minimizing system complexity.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The relay UE serves multiple functions: it acts as a wake-up signal forwarder, a data relay node, and a local base station for associated UEs. This multi-functionality reduces the need for dedicated infrastructure and simplifies the overall system architecture by using existing UEs to provide multiple services.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If relay UE handover is implemented for robustness, then system reliability against relay failure is improved, but handover complexity and signaling overhead increase

Engineering Contradiction:

Improverelay connection robustnessVSAvoidhandover management complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The network pre-configures multiple candidate relay UEs for each ultra-low-power UE before handover is needed. When the current relay UE fails or conditions deteriorate, the network can quickly switch to a pre-selected candidate relay UE, avoiding complex real-time selection procedures and reducing handover signaling overhead.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements monitoring mechanisms where the network and UEs track relay connection quality and relay UE status. This feedback enables proactive handover decisions based on measured parameters such as signal strength and relay UE availability, allowing handovers to be triggered by objective criteria rather than complex predictive algorithms.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS20250227784A1Power efficient and robust wake up signaling - relay migration

Publication Date: 2025.07.10 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

Systems and methods are disclosed for relay migration. In one embodiment, a method of operation of a network node for handover of one or more remote User Equipments (UEs) from a source relay UE to a target relay UE comprises determining that a triggering condition for handover of one or more remote UEs from a source relay UE to a target relay UE has occurred. The method further comprises, responsive to determining that the triggering condition has occurred, selecting one of a number of candidate target relay UEs as the target relay UE for the handover and causing handover and migration of state information to the target relay UE, the state information comprising state information of the one or more remote UEs.