Terminal Positioning via On-Demand PRU Activation

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Solution Overview

Problem

Current positioning methods using positioning reference units (PRUs) in cellular communication systems are inefficient due to infrequent reference signal transmission and introduce latency, particularly in applications requiring accurate and low-latency positioning, such as automotive applications.

Innovation Solution

The method involves direct PRU activation requests from the terminal device to the access node, followed by unsolicited reporting of activated PRUs to the location management function (LMF), allowing simultaneous PRU selection and activation with the location request, reducing latency by parallel processing of PRU activation and positioning procedures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If PRUs constantly transmit reference signals, then positioning accuracy is improved, but energy consumption increases and system efficiency deteriorates

Engineering Contradiction:
Improvepositioning accuracyVSAvoidenergy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic transmission of reference signals by PRUs instead of continuous transmission. The network device configures periodic reference signal resources, and PRUs transmit reference signals at scheduled intervals based on activation indications. This periodic action maintains positioning accuracy when needed while significantly reducing energy consumption during non-positioning periods.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent enables PRUs to autonomously transmit reference signals when activated by the network device, without requiring constant network control. The PRUs use pre-configured transmission parameters and autonomously execute reference signal transmission based on activation indications, reducing signaling overhead and improving system efficiency.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If PRUs are separately activated before positioning, then positioning accuracy is ensured, but latency increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidpositioning latency
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements preliminary configuration of reference signal resources and PRU activation states before positioning is actually needed. The network device pre-configures multiple PRUs with reference signal transmission parameters, and PRUs remain in a ready state with pre-configured resources. When positioning is triggered, the network device simply sends an activation indication, eliminating the need for separate activation procedures and reducing latency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent merges the reference signal configuration procedure with the positioning trigger procedure. Instead of separate activation and positioning steps, the network device sends a single positioning trigger message that simultaneously activates PRUs and initiates positioning measurements. This merging of procedures eliminates intermediate steps and reduces overall positioning latency.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If all PRUs are activated for positioning, then positioning robustness is improved, but system complexity and resource overhead increase

Engineering Contradiction:
Improvepositioning robustnessVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements selective activation of PRUs based on their local suitability for positioning the specific terminal device. The network device evaluates which PRUs are geographically close to the terminal device and activates only those local PRUs for reference signal transmission. This local quality approach ensures positioning robustness using only the necessary PRUs, reducing system complexity and resource overhead compared to activating all PRUs.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4476984B1Assisted positioning of terminal device
Publication Date: 2026.01.14 NOKIA TECHNOLOGIES OY
  • EP4476984B1 patent drawingFigure 1~2
  • EP4476984B1 patent drawingFigure 3~4
  • EP4476984B1 patent drawingFigure 5~6

AI summary

This document discloses a solution for assisted positioning of a terminal device. According to an aspect, a method performed by the terminal device comprises: transmitting, to a network element of a radio access network, a first message requesting activation of at least one positioning reference unit for positioning of the terminal device; receiving, from the network element, a second message causing an uplink reference signal transmission for the positioning of the terminal device; and performing the uplink reference signal transmission based on the second message.