Network Synchronization Status for Terminal Time Accuracy

Solution Overview

Problem

Existing location-based services face challenges in maintaining accurate time information in mobile terminals, particularly in asynchronous networks, leading to increased power consumption and degraded user experience due to frequent connections to satellites or networks for time synchronization.

Innovation Solution

A method and apparatus that determine and utilize network synchronization status to maintain accurate time in terminals, allowing for pseudo-synchronization across different networks, reducing the need for frequent assistance data requests and improving location determination speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If frequent connections to satellites or networks are made for time synchronization, then accurate time information is maintained, but power consumption increases

Engineering Contradiction:

Improvetime accuracyVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies preliminary action by obtaining network synchronization status information in advance from the cellular network before satellite signal acquisition begins. This pre-obtained synchronization status allows the receiver to predict satellite signal parameters ahead of time, reducing the need for frequent time updates during the acquisition phase and thereby lowering power consumption while maintaining time accuracy.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses the cellular network as an intermediary to provide synchronization status information that bridges the gap between ground-based time references and satellite signal acquisition. Instead of directly and frequently connecting to satellites for time synchronization, the terminal uses the cellular network's synchronization status as an intermediate source to maintain accurate time information with reduced power consumption.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If frequent assistance data requests are made, then accurate time information is maintained, but user experience degrades

Engineering Contradiction:

Improvetime accuracyVSAvoiduser experience

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The patent applies preliminary action by obtaining network synchronization status information in advance from the cellular network before satellite signal acquisition begins. This pre-obtained synchronization status allows the receiver to predict satellite signal parameters ahead of time, reducing the need for frequent time updates during the acquisition phase and thereby lowering power consumption while maintaining time accuracy.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses the cellular network as an intermediary to provide synchronization status information that bridges the gap between ground-based time references and satellite signal acquisition. Instead of directly and frequently connecting to satellites for time synchronization, the terminal uses the cellular network's synchronization status as an intermediate source to maintain accurate time information with reduced power consumption.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If large code and frequency search spaces are used for satellite signal acquisition, then comprehensive signal detection is achieved, but Time-To-First-Fix increases

Engineering Contradiction:

Improvesignal detection completenessVSAvoidTime-To-First-Fix

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by obtaining network synchronization status information in advance from the cellular network before satellite signal acquisition begins. This pre-obtained synchronization status allows the receiver to predict satellite signal parameters ahead of time, reducing the need for frequent time updates during the acquisition phase and thereby lowering power consumption while maintaining time accuracy.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies parameter changes by using the network synchronization status to dynamically adjust and narrow the code and frequency search spaces for satellite signal acquisition. When the network is synchronized to GNSS time, the terminal can reduce the search space based on this information, significantly decreasing the Time-To-First-Fix while maintaining reliable signal detection through selective refinement of search parameters.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP2368394B1Synchronization indication in networks

Publication Date: 2020.10.21 NOKIA TECHNOLOGIES OY

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AI summary

Systems and methods provide a network's synchronization status to a terminal when the terminal receives a transmission from the network. This network synchronization status can be indicated in accordance with various methods including, but not limited to the following: with a status flag in a network message; in a network capability indication; in a network's positioning capability indication; cell/network time relation information; in a time relation information of different Radio Access Technologies; and implicitly with another parameter and/or by a request for a certain measurement. When the network's synchronization status is determined, accurate time information/time assistance data can be maintained at the terminal.