Terminal Device, Network Node, and Methods Therein Dynamic QoS Configuration for 5G Sidelink Relay

This patent addresses the challenge of maintaining end-to-end quality-of-service in 5G networks when one user device relays traffic for another through a sidelink connection, providing a configurable framework that can adapt to changing radio conditions without forcing the network to repeatedly reconfigure every device in the relay chain.

The Problem

5G New Radio supports a relay architecture called Layer-2 UE-to-Network Relay, in which one user device (the relay UE) forwards traffic between a remote UE and the cellular network. This is useful for extending coverage, reducing power consumption on the remote device, and supporting devices that are outside direct network coverage. The technical challenge lies in quality-of-service management across two distinct radio links: the PC5 sidelink between the remote UE and the relay UE, and the Uu air interface between the relay UE and the base station (gNB). Each link has its own radio link control channels, latency budget, and packet error rate requirements. To satisfy end-to-end QoS, these parameters must be coordinated and split across both links. The existing approach assigns this responsibility to the gNB, which sends a semi-static configuration mapping PC5-RLC channels to Uu-RLC channels. However, radio conditions on both links change continuously. If the initial mapping becomes unsuitable, the gNB must trigger a full RRC Reconfiguration, which introduces significant delays, signalling overhead, and packet loss during the reconfiguration window. There is no mechanism for the remote UE or relay UE to receive a flexible, pre-provisioned set of configuration options they can apply adaptively without waiting for the gNB to react.

What This Invention Does

Ericsson‘s invention provides a method for the remote UE (referred to as the first terminal device) to receive from the network, the relay UE, or a control device a configuration that covers PC5-RLC channels, QoS requirements and Layer-2 parameters for the first link, and mappings between radio bearers carrying a service or flow and the available PC5-RLC channels. A complementary method covers the relay UE (second terminal device), which receives a corresponding configuration for its links. By pre-provisioning these configurations — including alternative mappings and QoS parameter sets — the system gives the relay UE and remote UE the information they need to adapt the channel mapping locally and dynamically, without waiting for RRC Reconfiguration from the gNB each time radio conditions shift. The patent covers the methods, the terminal devices, the network node, and the computer program products implementing the approach.

Key Features

• Comprehensive configuration delivery. The configuration sent to the remote UE includes PC5-RLC channel definitions, Layer-2 parameters for the PC5 link, QoS requirements, and mappings between radio bearers and PC5-RLC channels, giving the device a complete picture of how its traffic should traverse the relay.
• Relay UE complementary configuration. The relay UE receives its own configuration covering Uu and PC5-RLC channels, Layer-2 parameters for both links, and inter-channel mappings, enabling it to manage the traffic forwarding function with full QoS context.
• Reduced dependence on gNB reconfiguration. By providing richer configurations upfront, the design reduces the frequency with which full RRC Reconfiguration is needed to respond to changing conditions, lowering signalling overhead and avoiding packet loss during reconfiguration.
• Multiple configuration sources. The configuration can be delivered by the gNB, by the relay UE itself, or by a separate control device, accommodating different network deployment architectures.
• Coverage of both Uu and PC5 links. The system handles QoS and channel mapping across the complete two-hop relay path, not just the access link, enabling true end-to-end QoS enforcement for relayed traffic.

Who Is Behind It?

The applicant is Telefonaktiebolaget LM Ericsson (publ), the Swedish telecommunications infrastructure and standards leader. The named inventors are Nithin Srinivasan, Antonino Orsino, Min Wang, and Zhang Zhang, researchers specialising in 5G radio access architecture. This application is a divisional of AU 2022347799, which is the national phase of PCT/CN2022/119306, itself claiming priority from PCT/CN2021/122489 (filed 1 October 2021) and PCT/CN2021/119175 (filed 17 September 2021). The Australian patent attorney is FB Rice in Sydney.

Why It Matters

UE-to-UE relay and ProSe (Proximity-based Services) are among the features that make 5G relevant for public safety communications, rural coverage extension, vehicle-to-everything (V2X) applications, and smart industrial deployments. Maintaining reliable QoS across a relay chain is a prerequisite for these use cases, particularly in safety-critical contexts where packet delay or loss has real-world consequences. Australia’s public safety networks, remote mining and resources operations, and emerging V2X deployments on major road corridors are all potential beneficiaries of robust sidelink relay technology. Ericsson’s position as a 3GPP standards contributor means this patent family is potentially relevant to every 5G network equipment vendor implementing NR sidelink relay functionality.

Related Concepts

Ericsson’s patent addresses quality-of-service (QoS) management across multi-hop relay chains in 5G New Radio networks. The UE-to-network relay architecture extends coverage to devices outside direct base station range, with applications in public safety, rural broadband, and V2X communications.

The core challenge – coordinating QoS across the PC5 sidelink and Uu air interface simultaneously – sits at the heart of 3GPP Release 17 standardisation for NR sidelink relaying. Ericsson’s pre-provisioned configuration approach reduces signalling overhead compared to the conventional method of triggering full RRC reconfiguration each time radio conditions change.

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AU 2026201832 was published in the Australian Official Journal of Patents on 2 April 2026 and is open for public inspection. Patent applications represent inventions that are sought to be protected and do not necessarily reflect commercially available products.