Rotating Acoustic Identifiers for Location Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Real-time location systems face challenges in accurately tracking objects and personnel within large environments due to limitations in the number of unique identifiers for acoustic transmitting devices, which can lead to signal interference and security vulnerabilities.
Innovation Solution
Implementing a rotating set of identifiers for acoustic transmitting devices, where each device uses a unique identifier for a specific time period, allowing mobile devices to determine the location based on the detected identifier and time period, and utilizing additional location determination methods like GPS and RF access points for large installations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a fixed set of identifiers is used for acoustic transmitting devices, then the system is simple to implement, but the number of unique identifiers is limited leading to signal interference and security vulnerabilities
Solution Approach 1:
The patent implements dynamic identifier assignment where identifiers are not fixed but change over time. Each acoustic transmitting device is assigned a different identifier in each time period from a rotating set of identifiers, allowing the system to support many more unique devices than the size of any single identifier set would suggest.
Solution Approach 2:
The system divides time into periodic intervals or time periods, and rotates through different identifiers in each period. This periodic rotation of identifiers allows the same identifier to be reused for different devices at different times, effectively multiplying the number of unique device identities available in the system.
2Measurement precision
If multiple acoustic transmitting devices use the same identifier simultaneously, then the identifier set can be small, but signal interference occurs making location determination inaccurate
Solution Approach 1:
The patent implements periodic time-based identifier assignment where each acoustic transmitting device is assigned a unique identifier for a specific time period. During each time period, only devices with active identifiers transmit acoustic signals, eliminating signal interference between devices using the same identifier. The system rotates through different identifier assignments in successive time periods.
3Reliability
If traditional location tracking methods are used in large environments, then the system is simple, but security vulnerabilities and inability to distinguish devices with same identifier occur
Solution Approach 1:
The patent implements dynamic identifier assignment where identifiers are not fixed but change over time. Each acoustic transmitting device is assigned a different identifier in each time period from a rotating set of identifiers, allowing the system to support many more unique devices than the size of any single identifier set would suggest.
Solution Approach 2:
The system pre-rotates identifiers through a known sequence that is synchronized across all acoustic transmitting devices and the location determination system. This preliminary establishment of the rotating identifier sequence allows devices to be reliably identified without complex real-time negotiation or authentication protocols.
Data Source
AI summary
The present disclosure relates to a location determination system that includes acoustic transmitting devices and mobile devices. A mobile device receives acoustic signals (e.g., ultrasound signals) from an acoustic transmitting device. The mobile device must be able to identify the acoustic transmitting device with particularity when receiving the acoustic signals. It is more efficient to use a short identifier, for example 6 bits, for this purpose because it requires less power to transmit and decode. By utilizing the rotating identifier system described herein, more acoustic transmitting devices can be distinguished than using a time-invariant identifier would otherwise provide, and the transmissions are more secure and therefore less vulnerable to free-riders.