NR Relay WTRU Latency Reduction via Pre-allocated Resources

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Solution Overview

Problem

Current wireless communication systems face challenges in reducing latency when a wireless transmit/receive unit (WTRU) needs to communicate with another WTRU or the network that is out of range, particularly in relay scenarios, where existing techniques are inadequate for ensuring end-to-end packet delay bounds in New Radio (NR) sidelink communications.

Innovation Solution

The implementation of a relay WTRU configured to relay information between a remote WTRU and the network, utilizing specific rules, parameters, and configurations to control and reduce latency, including message exchanges between the remote WTRU and the relay WTRU, and between the relay WTRU and the network, to align resources and timing for proper latency management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a relay WTRU is used to communicate with a remote WTRU or network that is out of range, then communication coverage is extended, but latency increases due to the additional relay hop

Engineering Contradiction:

Improvecommunication coverage areaVSAvoidcommunication latency

Core Design Contradiction:

Area of stationary objectVSLoss of time

Solution Approach 1:

The relay WTRU is configured with pre-allocated uplink resources and timing advance values before data needs to be relayed. When data arrives from the remote WTRU, the relay WTRU can immediately transmit it to the network using pre-configured resources, eliminating resource allocation delay and reducing overall latency while maintaining extended coverage capability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The relay WTRU acts as an intermediary that maintains direct connections to both the remote WTRU and the network simultaneously. By pre-synchronizing timing with the network and maintaining ready-state resources, the intermediary relay minimizes the time penalty typically associated with multi-hop communication while preserving the extended coverage benefit

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of time

If strict rules and parameters are imposed on relay WTRU to ensure end-to-end packet delay bounds, then latency is reduced, but device complexity increases

Engineering Contradiction:

Improvepacket delayVSAvoidrelay configuration complexity

Core Design Contradiction:

Loss of timeVSDevice complexity

Solution Approach 1:

The relay WTRU autonomously applies pre-configured timing advance values and uses pre-allocated resources without requiring complex real-time negotiations or adjustments. The device self-manages the relaying process using stored configuration parameters, reducing the need for complex control logic while ensuring packet delay bounds are met

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

Specific parameters such as timing advance values and uplink grant configurations are optimized for relay operation. By pre-setting these parameters with appropriate values that account for the relay hop, the system ensures packet delay requirements are satisfied without requiring complex runtime parameter adjustment mechanisms

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20230309161A1NR relays methods for supporting latency reduction for SL relays

Publication Date: 2023.09.28 INTERDIGITAL PATENT HOLDINGS INC

AI summary

System(s), method(s), and device(s) for addressing new radio (NR) sidelink latency and protocols. A relay wireless transmit receive unit (WTRU) may be configured to relay information between a remote WTRU and the network. Certain rules, parameters, thresholds, and/or configurations may be used to control and/or reduce latency. In one example, the remote WTRU may send a message to the relay WTRU indicating parameters for data to be relayed; and the relay WTRU may send a message to the network regarding the same.