Prof. Maarten Weyn gave a presentation on low-power communication and localization. He discussed his research in localization from opportunistic to just enough systems and low-power communication. Weyn is also the founder of one spin-off company and helped facilitate two others. He discussed low-power applications that can run for years on AA batteries or other small batteries. Weyn also covered the DASH7 protocol for low-power, mid-range wireless sensor communication and its open standard for sub-GHz ISM bands.

1. The increasing need for
low-power, long-range communication and
localization
Prof. Maarten Weyn
Wipro – May 7th 2015
maarten.weyn@uantwerpen.be

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3. Maarten Weyn
Research
• Localization
from Opportunistic to Just Enough
• Low-power communication
• Low-power embedded systems
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4. Maarten Weyn
Education
• Mobile Communication (Eng.)
• Digital Communication
• Ambient Intelligence – Low Power
Connected Systems (Eng.)
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5. Maarten Weyn
Entrepreneurship
• Founder of 1 spin-off company
• Facilitator of 2 other spin-off
companies
• Director of DASH7 Alliance
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Courtesy of
Postscapes
& Harbor
Research.

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Courtesy of
Postscapes
& Harbor
Research.

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Courtesy of
Postscapes
& Harbor
Research.

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Courtesy of
Postscapes
& Harbor
Research.

12. 12
Courtesy of
Postscapes
& Harbor
Research.

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Courtesy of
Postscapes
& Harbor
Research.

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17. Low-Power
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0.5 – 5 Watt

18. Low-Power Microcontrollers
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19. Low-Power Applications
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• 2 AA batteries
• 1 year
• 650 μW

20. Low-Power Applications
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5 years
8.6 Wh battery
0.2 mW

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23. Low Power Communication
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Frequency
Data rate
Range
Standardization
Power Consumption
Integration capabilities

24. Frequency
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433 868/915 2400 MHz

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Data rate
0.1 250 1000 kbps1000.3 9.6 20 50

26. Range
100 5 km 50km30
Low-Range Long-Range
Mid-Range
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27. Standardization
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28. 8100.231 0.306 4 19001 4750.390 0.550
Power Consumption
Energy
Energy (mJ)
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29. Smartphone integration
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31. Localization
Signal Strength
• Attenuation
• Pattern Matching (Fingerprinting)
• Presence / Proximity
Time (Ranging)
• Time of Flight - Time Difference of Arrival
• Round Trip Time
Direction Finding / Angle of Arrival

32. Signal Strength
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Proximity

34. Frequency vs Range

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Origin
The Dash7 Alliance Protocol originates from ISO/IEC 18000-7,
The DASH7 Alliance (D7A) enhanced ISO 18000-7 for
Ultra Low Power, Mid-Range Wireless Sensor Communication.
The DASH7 Alliance expanded the air interface to all sub-GHZ
ISM/SRD bands.

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Open
Standard
Ultra
Low Power
Mid-Range
Sub-GHz
ISM Bands

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Distance – Complexity – Energy – Latency
Tree MeshStar
Passive RFID
Tags can only be
read in the
intermediate
proximity of a
reader
Active RFID
Longer range
interrogators –
Master/Slave
DASH7: Extensible Star
Simple routing
Asynchronous
Tag-Talk-First
Tag-to-Tag
Mesh
Range depends on number of
router nodes
Congestion – Routing Complexity – Latency
Routers need to be powered
Each hop consumes energy
Network Topology

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Asynchronous Communication

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Power Budget
14%
< 1%
35%
50%
Total Average Consumption: 52 μA

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Full Stack Data
Element
Smart
Addressing
Security
Privacy

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Roles
Authentication
Permissions
Data Elements
DASH7 Stack Config
Application Data

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USE CASE
Collection of humidity sensor data

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Traditional Approach
Application periodically measures
humidity and sends data to the
gateway.
Application implements communication

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Application periodically measures
humidity and writes value to the
file system
Data Elements can be accessed by
DASH7
Data Elements

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Application periodically measures
humidity and writes value to the
file system
Gateway queries data from Data
Element
All Nodes matching query answer
with requested data
Queries

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NotificationApplication periodically measures
humidity and writes value to the
file system
DASH7 detects change in Data
Element
If criteria is matched, Sensor
notifies requested data

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Context Aware Sensor and Actuator Data Propagation
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Write and read to/from files
Configure system through configuration files
Configured through file system
Handles scheduled scan cycles
Handles queries from other devices
Handles queries and notifications on file changes
File system configurable over the air

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Open Source Stack for DASH7

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Open Source Stack for DASH7

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Talbot House
BELIGUM

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The increasing need for
low-power, long-range
communication and
localization
Prof. Maarten Weyn
Wipro – May 7th 2015
maarten.weyn@uantwerpen.be