RF Presence-Sensing Receiver Using Inter-Network Signals
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Solution Overview
Problem
Existing RF presence-sensing arrangements require a large number of RF transceivers to cover a sufficiently large sensing space due to limited presence-sensing volumes defined by the line of sight and multipath propagation, leading to high hardware expenditure.
Innovation Solution
The arrangement employs two or more local-area RF communication networks with inter-network RF sensing signals to create a bridging presence-sensing volume, reducing the need for extensive hardware by leveraging RF transceivers at larger distances and combining signal strengths from multiple networks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a large number of RF transceivers are deployed to cover a sufficiently large sensing space, then the presence-sensing coverage is improved, but the hardware expenditure increases
Solution Approach 1:
The patent combines multiple local-area RF communication networks into a unified presence-sensing arrangement. RF transceivers from different networks (first network spanning first presence-sensing volume, second network spanning second presence-sensing volume) work together to create an extended sensing capability, merging their individual sensing volumes into a larger coordinated sensing space without requiring each network to independently cover the entire area.
Solution Approach 2:
RF transceivers are configured to perform multiple functions: they participate in their own local-area network for intra-network communication while simultaneously receiving inter-network RF sensing signals from other networks. This multi-functionality allows each transceiver to contribute to both its local network's presence sensing and the overall multi-network presence sensing, reducing the total number of transceivers needed.
2Quantity of substance
If RF transceivers are placed at larger distances to reduce hardware requirements, then the hardware expenditure is reduced, but the detection accuracy may deteriorate
Solution Approach 1:
The system merges signal-strength information from multiple RF sensing signals (both intra-network and inter-network signals) to determine presence. By combining measurements from multiple transceivers at larger distances, the system maintains detection accuracy through aggregated data while reducing the need for densely spaced transceivers.
Solution Approach 2:
The system uses signal-strength determination units to continuously measure and evaluate the strength of received RF sensing signals. This feedback mechanism allows the presence detection unit to assess presence conditions based on actual signal measurements, adjusting detection decisions based on the quality and strength of signals received from transceivers at various distances.
3Volume of stationary object
If the presence-sensing volume is extended beyond direct line of sight using inter-network signals, then the sensing coverage is improved, but the system complexity increases
Solution Approach 1:
The extended presence-sensing arrangement is segmented into multiple manageable local-area RF communication networks, each spanning a defined presence-sensing volume. This segmentation allows the complex task of covering large spaces to be divided into smaller, independently configurable networks that can be deployed and managed separately while working together through inter-network signal exchange.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances detection accuracy and reduces hardware requirements by extending the sensing volume beyond the direct line of sight, allowing for more efficient coverage with fewer transceivers.
Implementation Method 1
signal absorption and signal forward and reflected backscatter of RF sensing signals caused by the presence of a biological mass
Implementation Method 2
signal forward and reflected backscatter of RF sensing signals caused by the presence of a biological mass
Data Source
AI summary
The invention is directed to a receiver (100) for an RF presence-sensing arrangement (150). The receiver is configured to receive a first intra-network RF sensing signal (102) from a first transmitter (104), both pertaining to a first local-area RF communication network (106) spanning a first presence-sensing volume (114) and to additionally receive an inter-network RF sensing signal (108) from a second transmitter (110) pertaining to a second local-area RF communication network (112), thus spanning a third presence-sensing volume (120) and to provide a first and an inter-network signal-strength signal (S1, S3) indicative of a respective received-signal strength. In the RF presence-sensing arrangement, a presence detection unit (122) is configured to provide, based on the signal-strength signals, a presence detection signal (SDET) indicative of a change in presence of a subject or object in the first or in the third presence-sensing volume, thus increasing the accuracy of the presence determination.