Indoor Positioning with Dynamic Access Point Power Control
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Solution Overview
Problem
Conventional indoor positioning systems using RSSI measurements from access points with dynamic transmission power control are ineffective due to the unknown and varying transmission power, which prevents accurate determination of position fixes.
Innovation Solution
Receiving transmission power data from a central entity or positioning assistance server, and using this data along with RSSI values and heatmaps to determine a position fix for mobile platforms, either on the platform itself or by the server, providing updated RSSI heatmap information to the platform for navigation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If access points use dynamic transmission power control to adapt to changing environmental conditions, then system adaptability improves, but transmission power becomes unknown and varies, making accurate RSSI-based positioning impossible
Solution Approach 1:
The patent introduces an intermediary component (positioning assistance server or central entity) that mediates between the access points and the mobile platform. This intermediary collects transmission power data from access points and provides it to the mobile platform, enabling accurate positioning without requiring the mobile platform to directly query access points. The intermediary resolves the contradiction by making transmission power information available while allowing access points to maintain dynamic power control for adaptability.
Solution Approach 2:
The system performs preliminary action by having the mobile platform receive transmission power data from an intermediary before attempting to determine its position. This pre-acquisition of transmission power information allows the platform to accurately interpret RSSI measurements and calculate position fixes, even though the power levels are dynamic. The preliminary receipt of power data resolves the timing and information availability issue.
2Measurement precision
If mobile platforms directly query access points for transmission power data, then positioning accuracy improves, but energy and bandwidth are wasted due to frequent communication overhead
Solution Approach 1:
The intermediary (positioning assistance server) eliminates the need for mobile platforms to directly query access points for transmission power data. Instead, the intermediary collects and stores this information centrally and provides it to mobile platforms on demand. This reduces energy consumption and bandwidth usage by eliminating repeated direct communications between mobile platforms and access points, while still providing accurate positioning data.
Solution Approach 2:
The system creates a copy of the transmission power data and stores it in the intermediary (positioning assistance server). Mobile platforms receive this copied data rather than querying access points directly. This copying mechanism allows multiple mobile platforms to obtain the same power information without generating additional communication overhead with the access points, thereby conserving energy and bandwidth.
3Device complexity
If conventional RSSI measurements are used without transmission power data, then system simplicity is maintained, but positioning cannot be performed in environments with dynamic power control access points
Solution Approach 1:
The patent segments the positioning system into distinct functional components: access points that transmit signals, an intermediary (positioning assistance server) that manages transmission power data, and mobile platforms that perform positioning calculations. This segmentation allows each component to perform its specialized function efficiently. The access points maintain simple transmission, the intermediary handles the complexity of power data management, and mobile platforms focus on positioning, thereby achieving both simplicity and adaptability.
Solution Approach 2:
The intermediary serves as a mediator that bridges the gap between conventional RSSI measurements and dynamic power control environments. It provides the missing transmission power information to mobile platforms, enabling them to perform accurate positioning calculations. This intermediary approach extends the capability of conventional RSSI-based positioning to work in dynamic power control environments without fundamentally changing the mobile platform's operation.
Data Source
AI summary
A position fix for a mobile platform is determined using RSSI values for wireless signals received from access points (APs), at least one of which has dynamic transmission power control. The transmission power data for the APs is received from an entity separate from the APs, e.g., a central entity or a positioning assistance server. The RSSI values for wireless signals received from the APs are acquired, as is an RSSI heatmap. Using the transmission power data, the RSSI values and the RSSI heatmap, the position fix for the mobile platform is determined. The position fix may be determined by the mobile platform or a positioning assistance server. Additionally, a server may receive transmission power data for APs and may provide to a mobile platform RSSI heatmap information based on the transmission power data. The RSSI heatmap information may be, e.g., the transmission power data or a RSSI heatmap.