Radio Map Self-Healing via Harvest Trace Updates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional GPS-based location determination in mobile devices is prone to errors in areas with obstructed line of sight, such as buildings and tunnels, leading to inaccurate location identification, especially in determining floor, room, side of street, or block levels.
Innovation Solution
A method that involves receiving and processing 'harvest traces' from mobile devices, which include multiple location fixes with RSSI measurements from wireless access points, for updating and self-healing of radio maps by comparing and filtering data to account for changes in the venue's wireless signal environment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS signals are used for location determination, then outdoor location can be determined, but accuracy deteriorates in areas with obstructed line of sight such as buildings and tunnels
Solution Approach 1:
The patent introduces wireless access points as intermediary objects to establish indirect communication paths between mobile devices and positioning infrastructure. When direct GPS satellite signals are blocked by buildings or tunnels, the system uses Wi-Fi access points as mediators to transmit positioning information, enabling location determination in GPS-denied environments through an alternative communication channel.
Solution Approach 2:
The patent replaces the GPS satellite-based electromagnetic positioning system with a terrestrial Wi-Fi infrastructure-based positioning system for indoor and obstructed environments. Instead of relying on satellite signals that penetrate poorly through building materials, the system substitutes a local wireless network infrastructure that operates effectively within indoor spaces, achieving accurate positioning where GPS fails.
2Measurement precision
If radio map data is updated frequently to maintain accuracy, then positioning precision improves, but data processing complexity and energy consumption increase
Solution Approach 1:
The patent implements periodic updating of radio map data at scheduled intervals rather than continuous real-time updates. Mobile devices contribute location and signal strength measurements at predetermined time intervals, allowing the system to maintain positioning accuracy while reducing the frequency of data processing and energy consumption associated with constant updates.
Solution Approach 2:
The patent employs partial updating of radio map data by only processing and incorporating measurements from a subset of mobile devices rather than all devices. This selective approach maintains positioning accuracy through sufficient data samples while reducing overall computational load and energy consumption in the network.
Data Source
AI summary
A method comprising: receiving a harvest trace from a mobile device, the harvest trace including a plurality of location fixes each corresponding to a location at a venue, each location fix associated with data including one or more RSSI measurements of one or more wireless signals received from each of a plurality of wireless access points positioned at the venue, the plurality of location fixes including at least two location fixes that have a positional relationship with each other; comparing the data associated with one of the location fixes with data associated with a reference point identified in a radio map of the venue; and updating the radio map of the venue by updating the data associated with the reference point based on the data associated with the one of the location fixes.