Localization in the IOT Embedded Software Engineer PhD in Wireless Communication Protocols and Radio Localization B. J. Dil
This presentation Why? Localization in IOT ≈ Energy efficient indoor GPS Short overview of Radio Localization systems in IOT Focus on large-scale Technology Applications
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Contents Main types of localization systems: TDOA-based localization systems RSS-based localization systems
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Main types of localization systems: Time-Difference-Of-Arrival
WHEN two transmitters transmit pulse at same time: Receiver receives pulse at different times based on distance. TDOA uses the difference between arrival times to locate receiver.
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Main types of localization systems: Received Signal Strength
WHEN one transmitter transmit signal: Signal strength decreases over distance. RSS-based localization uses RSS to estimate distance.
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Contents Main types of localization systems: TDOA-based localization systems RSS-based localization systems
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First Radio Localization Systems (naval/maritime) Highly synchronized fixed infrastructure Transmit signals (>1000 km)
Source: https://commons.wikimedia.org/wiki/Category:LORAN-C_transmitter_Rantum 7
First Radio Localization Systems (naval/maritime) Highly synchronized fixed infrastructure Transmit signals
Mobile receivers Receive signals
Source: https://commons.wikimedia.org/wiki/File:LORAN_AN-APN-4_receiver_set.jpg 8
First Radio Localization Systems (naval/maritime) Highly synchronized fixed infrastructure Transmit signals
Mobile receivers Receive signals
Localization@Receiver
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First Radio Localization Systems (naval/maritime) Highly synchronized fixed infrastructure Transmit signals
Mobile receivers Receive signals
Localization@Receiver Technology: Time-Difference-Of-Arrival of transmitted signals => Speed of light e.g. Loran 10
Current Radio Localization Systems Highly Synchronized Fixed infrastructure Transmit signals Receive signals
Source: https://www.zebra.com/us/en/solutions/location-solutions/enabling-technologies/wherenet.html 11
Current Radio Localization Systems Highly Synchronized Fixed infrastructure Transmit signals Receive signals
Mobile receivers transmitters Receive signals Transmit signals (up to 1 km)
Source: https://www.zebra.com/us/en/solutions/location-solutions/enabling-technologies/wherenet.html 12
Commercial Radio Localization Systems Highly Synchronized Fixed infrastructure Transmit signals Receive signals
Mobile receivers transmitters Receive signals Transmit signals
Localization @Receiver @Server
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Commercial Radio Localization Systems Highly Synchronized Fixed infrastructure Transmit signals Receive signals
Mobile receivers transmitters Receive signals Transmit signals
Localization @Receiver @Server
Technology: Time-Difference-Of-Arrival of transmitted signals => Speed of light
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Complete solutions are available on the market TDOA deployed in Rotterdam: https://www.youtube.com/watch?v=kUF033RdUUc&feature=youtu.be
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Technology, Requirements and Performance: TDoA Requirements: 1. 2.
Highly synchronized infrastructure Hardware support (e.g. not available on BLE and ZigBee)
Performance: Depends on temporal frequency bandwidth
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Contents Main types of localization systems: TDOA-based localization systems RSS-based localization systems
What’s next...
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Commercial localization systems: RSS (far field) Solution indoor RSS: WiFi/BLE radio Inertial sensors on smartphone
Source: https://commons.wikimedia.org/wiki/File:Beacons_by_jnxyz.education_(13570846665).jpg 18
Commercial localization systems: RSS (far field) Solution indoor RSS: WiFi/BLE radio Inertial sensors on smartphone Rough estimate of predefined routes
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Commercial localization systems: RSS (far field) Solution indoor RSS: WiFi/BLE radio Inertial sensors on smartphone Rough estimate of predefined routes Calibration phase or Position of WiFi routers/BLE modules Points of interest
Example of smartphone indoor localization system: https://www.youtube.com/watch?v=dCJrmFdv8MQ
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Technology, Requirements and Performance: RSS (far field) Requirements: 1.
Available on any radio (BLE/WiFi/ZigBee/LoRa)
Performance RSS only: Depends on spatial frequency bandwidth ≈ Density of measurements over space
Note performance: Inertial sensors on smartphone => relate measurement positions to each other Rough estimate of predefined routes => limit solution space 21
Technology, Requirements and Performance: RSS (far field) Rule of thumb: Average localization/ranging accuracy: ~20-30% of distance between transmitters Example: ~10-15 meters
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Contents Main types of localization systems: TDOA-based localization systems RSS-based localization systems
What’s next...
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What’s next? What about existing IOT deployments with: Fixed transmitters with unknown positions (e.g. ZigBee or BLE network)?
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What’s next? Fixed receivers? Increase deployment costs... Performance depends on fixed receiver density...
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What’s next? Use mobile receiver with unknown position: Measure RSS to fixed transmitters with unknown position
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What’s next? Move through environment with mobile receiver while measuring RSS, Position fixed transmitters relative to fixed transmitters with known positions
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What’s next? Solution indoor RSS: Inertial sensors Rough estimate of predefined routes Calibration or Position few transmitters + Move around with radio with unknown position
Performance: Density of measurements over space
Smartphone app@end of autumn (BLE & WiFi) 28
What’s next? Advantages: Only RSS => Available on any hardware platform Unobtrusive => Intercept wireless communication No knowledge about deployment environment
Requirements: Mobile receiver
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Questions?
[email protected]
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