Low power short-range radio
technology
For industrial automation, commercial buildings and residential control
WCI – FHTW
Berlin; 12 October 2007
Agenda
 Presentation of Danfoss
 Product evolution
 Low-cost, low power, short-range radio technology
 Some examples of wireless control systems
HE-CTC - Lowcost lowpower shortrange radio technology - 12/10-2007 Berlin
2
Headquarters
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Executive Committee
Jørgen M. Clausen
Niels B. Christiansen
Hans Kirk
Frederik Lotz
President & CEO
Vice CEO & COO
Executive Vice President & CDO
Executive Vice President & CFO
Corporate
Functions
&
Services
Danfoss
Ventures
Danfoss
Refrigeration &
Air Conditioning
Division
Danfoss Heating
Division
Danfoss Motion
Controls Division
Kim Fausing
President
Nis Storgaard
President
Sven Ruder
President
Danfoss Comfort Controls
•
Danfoss District Heating
•
Danfoss Burner Components
•
Danfoss Floor Heating
•
Danfoss Heat Pumps
•
Danfoss Water Controls
Danfoss Drives
•
Danfoss Gearmotors
•
Danfoss Silicon Power
•
Danfoss Solar Inverters
Danfoss Automatic Controls
•
Danfoss Compressors
•
Danfoss Electronic
Controls & Sensors
Danfoss Services
Division
Kjeld Stærk, President
Danfoss Global
Business Services
•
HE-CTC - Lowcost lowpower shortrange radio technology - 12/10-2007 Berlin
Danfoss Industri
Service
•
Danfoss Group
Procurement
•
Owner share
38.2%
Danfoss Business
System
4
Group figures
Danfoss is a family-owned, global company
(no public shares, but approx. 3% employee shares)
Net sales 2006: EUR 2,600 mill
Employees: 21,400 worldwide (April 2007)
Production of 250,000 items per day
Europe
North
Latin
America America
Africa
Asia
Manufacturing sites
45
11
2
1
5
Sales companies
71
6
6
1
12
Agents and distributors
HE-CTC - Lowcost lowpower shortrange radio technology - 12/10-2007 Berlin
Pacific Total
64
2
98
114
5
Product range
Danfoss Refrigeration & Air Conditioning Division
Danfoss Automatic
Controls
Controls for
Commercial
Refrigeration & A/C
Controls
Danfoss Automatic
Controls
Controls for
Industrial
Refrigeration
Danfoss Automatic
Controls
Industrial
Automation
Danfoss Electronic
Controls & Sensors
Electronic
Controls for
Refrigeration
Danfoss
Compressors
Household
Compressors
Danfoss
Compressors
Commercial
Compressors
Danfoss Floor
Heating
Danfoss Heat
Pumps
Danfoss Burner
Components
Danfoss
Compressors
Sub-Assemblies
Danfoss
Compressors
Thermostats
Danfoss Heating Division
Danfoss Comfort
Controls
Danfoss District
Heating
Danfoss District
Heating
Danfoss Water
Controls
Danfoss Motion Controls Division
Danfoss Drives
Danfoss Gearmotors
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Product evolution
Mechanical
on-off control
Mechanical thermostat
Thermostat with
micro processor
Electronic
thermostat
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Thermostat with
communication
Wireless heat control
7
Low cost low power networks
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Low cost, low power networks



It is not
•
GSM/GPRS etc
•
BlueTooth
•
Wireless LAN
Is networks of devices rarely speaking, and rarely awake
•
Sensors, actuators and remotes etc. for home automation
- Climate control
- Ligth control
- Entertainment
- security
•
Sensors, actuators and monitoring systems for industrial applications
- Pressure, vibration, temperature etc.
- Motors (conveyers etc.)
- valves
An application may be
•
Full home automation
•
Single applications within the home like heating, lighting etc.
•
Food safety monitoring in a supermarket
•
Energy optimization of a plant
•
Predictive maintenance system for a factory
•
Asset tracking system
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Design goals for wireless
solutions

Must work as reliable as wired solutions
Challenges are:
- Range
- Coverage
- Interference from electrical equipment
- Interference from other radios
- Security (Hacking)

Must be easy to install
Challenges are:
- Each device must be assigned to the network
- Each device must have an address
- Routing must be setup if it is a meshed network
- Security credentials must be setup
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Range & coverage

Good range comes from good radio design
•
Good quality radio chip
•
Good antenna design

Good coverage comes from the signal coding (chosen RF technology)

RF damping
•
The damping of RF signals increased with the frequency, which is for all materials
including air
How multipath fading affects coverage
1
a
b
•Signal a is the direct signal, traveling the shortest distance
2
•Signal b is the signal reflected by the black wall, ant traveling a
longer distance
•Due to the difference in distance the signals do not arrive at the
same time
•Depending of the phase difference between a and b at arrival, the
resulting signal is either reduced, or completely eliminated
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Meshed network improves
both range and coverage
1
7
Traditional star network
6
•Very simple, and the traditional way of thinking
5
•All nodes mustbe within direct range (5 can’t be used)
1
•Weak links will need many retransmissions (6)
4
2
•Will have problems if obstacles blocks radio transmission (2 can’t be
used)
•Links may be weak because of multipath fading (7 having signal
reflected)
3
Meshed network
3
7
6
•Nodes with mains power will be able to forward messages
•Obstacles can beovercome (2 sends its packets to 3, who forwards to
1)
5
1
•Weak links are not used (6 sends its packets to 4, who forwards to 1)
4
2
•Range can be extended (5 sends its packets to 4, who forwards to 1)
•Multipath fading may be overcome (7 sending through 6 and 4)
3
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Interference and frequency
bands



Electrical equipment generates noise
•
Some electrical equipment generates a lot of noise in the RF spectrum used for
communication
•
Examples are:
- Relays
- Motors (motors with brushes are particular bad)
- Florescent lamps
Other radio systems may create interference in your band
•
Most of the RF spectrum is regulated, and interference should not happen there
•
But for lowcost solutions unlicenced bands are the most attractive
Commonly available unlicenced bands are:
•
433 MHZ (EU only)
- Known to be prone to interference, since it is also used by baby alarms, toys, HAM radio
etc.
- There are no duty cycle restrictions
•
868 MHz (EU) / 915MHz (US)
- The band is dedicated to monitoring and control applications
- There are dutycycle restrictions in EU
- Any one is only allowed to send 1% of the time
- Therefore there is a low probability of collisions
•
2.4GHz (almost world wide)
- Heavily used by wireless LAN
- No duty cycle restrictions
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Security (hacking)
For a wired system one needs physical access to the wires, to
read, modify or inject signals
On wireless systems one can do this from outside the building
or wiring closet
 There is a need to consider the following:
• Authentication
• Integrity
• Replay attacks
• Non repudiation
 These should always be considered with a certain threat model
in mind
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Easy installation

The people installing are not IT guys

Most of the devices have no interface to set addresses etc.

In many cases it must be possible to do all functions with just one button and a
LED

Most people do not want fancy installer tools

The good thing is that most of the wireless communication platforms available,
supports easy installation out of the box

It is enough for the user to press on button on each device, and then the protocol
will take care of the rest by it self.

Then there is only the application configuration left:
•
Like telling a light switch what lamp it should control
•
Like telling a thermostat that it is should control the heat in the living room
•
Like telling another switch that it is for the doorbell
•
Etc.
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Relevant existing standards



Z-Wave
•
Invented by Zensys
•
Now standardized by the Z-Wave alliance
•
Based on FSK radios in 868/915 MHz bands
•
Chip and stack supplier: Zensys
Konnex RF
•
Standardized by KNX Association
•
Based on FSK radios in 868/915 MHz bands
•
Mainly meant to be an extension of the wired Konnex standard
•
Chip supplier: Any FSK radio capable of running in the bands
•
Stack supplier: Weinzierl Engineering GmbH, and maybee others
Enocean
•
Invented by Enocean and standardized by EnOcean
•
Based on ASK radio in 868/915 MHz bands
•
Optimized for battery less devices
•
CHIP and stack supplier: EnOcean
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Potential upcoming standards



ZigBee
•
Standardized by the ZigBee alliance
•
Based on IEEE802.15.4
- DSSS radios in 2,4 GHz or 868/915 MHz bands
•
Chip supplier: Freescale, Chipcon, Atmel, Jennic, Integration and others
•
Stack supplier: Figure8wireless, AirBee, Atalum, Mindtec, Helicom and Ember
6LOPAN
•
Standardized by IETF
•
Based on IEEE802.15.4
•
Chip supplier: Freescale, Chipcon, Atmel, Jennic, Integration and others
•
Stack supplier: Arch Rock, Invensys and some universities
IP500
•
Standardized by IP500 alliance
•
Based on IEEE802.15.4
- DSSS radios in 2,4 GHz or 868/915 MHz bands
•
Chip supplier: Under NDA
•
Stack supplier: None so far
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Examples of industrial and large
scale commercial applications
HE-CTC - Lowcost lowpower shortrange radio technology - 12/10-2007 Berlin
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Wireless heating control
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Wireless floor heating system
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Thank you !
Contact:
Søren
Hansen



Manager Communication Technology
Danfoss A/S
Shansen @ danfoss .com