Peer-to-Peer Satellite Positioning Assistance for Mobile Devices

Solution Overview

Problem

Mobile communication devices operating outside network coverage face significant delays in acquiring positioning signals due to the lack of satellite positioning assistance information, leading to prolonged location determination times.

Innovation Solution

A method where a mobile communication device receives satellite positioning assistance information directly from a peer device that has already determined its location, reducing the need for a cold start and accelerating the location determination process through direct peer-to-peer communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a satellite positioning receiver performs a cold start to determine location autonomously, then location determination can be performed without network coverage, but the time required for location determination becomes significantly prolonged (several minutes or more)

Engineering Contradiction:

Improvelocation determination capabilityVSAvoidtime to first fix

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the mobile communication device acquire and store satellite positioning assistance information (ephemeris data, almanac, approximate location, time synchronization data) from the communication system before entering direct communication mode. This pre-acquired information is then utilized during peer-to-peer communication to significantly reduce the time required for satellite signal acquisition and location determination, avoiding a complete cold start search.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses the communication system and peer mobile devices as intermediaries to transfer satellite positioning assistance information. Instead of the positioning receiver performing an autonomous cold start search, the assistance information is transmitted via the communication system or directly from a peer device that has previously acquired it, acting as a mediator to provide the necessary data for rapid location determination.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If a mobile communication device operates in direct communication mode outside network coverage, then it can communicate without base station support, but satellite positioning assistance information becomes unavailable

Engineering Contradiction:

Improvecommunication capabilityVSAvoidsatellite positioning assistance information

Core Design Contradiction:

Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent applies preliminary action by acquiring and storing satellite positioning assistance information (ephemeris data, almanac, approximate location, time synchronization data) from the communication system before entering direct communication mode. This pre-acquired information is then utilized during peer-to-peer communication to significantly reduce the time required for satellite signal acquisition and location determination, avoiding a complete cold start search.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses the communication system and peer mobile devices as intermediaries to transfer satellite positioning assistance information. Instead of the positioning receiver performing an autonomous cold start search, the assistance information is transmitted via the communication system or directly from a peer device that has previously acquired it, acting as a mediator to provide the necessary data for rapid location determination.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Measurement precision

If a satellite positioning receiver searches for satellite signals without assistance information, then it can determine location autonomously, but the search time increases significantly due to unknown satellite positions and Doppler shifts

Engineering Contradiction:

Improvelocation accuracyVSAvoidsignal acquisition time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the mobile communication device acquire and store satellite positioning assistance information (ephemeris data, almanac, approximate location, time synchronization data) from the communication system before entering direct communication mode. This pre-acquired information is then utilized during peer-to-peer communication to significantly reduce the time required for satellite signal acquisition and location determination, avoiding a complete cold start search.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by enabling mobile devices to share their acquired satellite positioning assistance information with peers through direct communication. When one device acquires ephemeris data, almanac, or time synchronization information, it can transmit this information to other devices in the vicinity, allowing them to avoid redundant search processes and significantly reduce their signal acquisition time.

Inventive Principle:

Principle #23Feedback

Data Source

PatentEP1929326B1Method for providing location aiding among peers operating in a direct communication mode

Publication Date: 2014.02.26 MOTOROLA SOLUTIONS INC

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AI summary

A mobile communication device (202) outside the service area of a communications network 210 in need of satellite positioning assistance information to perform a location determination (308). The mobile communication device receives the assistance information from a peer mobile communication device (204, 206) over a direct link.