Wireless Sensor Networks (WSNs)

Wireless Sensor Networks
An Introduction to Technologies, Applications, and
Architecture
Teppo Myllys
District Sales Manager, National Instruments
Agenda
• Definition and Applications
• Wireless Sensor Network System Components
• Technology Considerations
Network Topologies
ƒ Communication Standards
ƒ Power Consumption
ƒ
• NI Wireless Sensor Networks
• Develop a Wireless Sensor Network Measurement System
Wireless Sensor Networks (WSNs)
Defined as a wireless network that consists of spatially distributed devices
that use sensors to monitor physical or environmental conditions
Applications include:
• Environmental monitoring
• Structural monitoring
• Industrial machine monitoring
• Power quality and consumption
• Building and home automation
• Health care
• Asset monitoring
Structural Health Monitoring of the 2008 Olympic
Venues in Beijing
Application: LabVIEW and CompactRIO for structural
health monitoring (SHM) determine stability, reliability,
and livability of mega-structures in China
Challenge: Developing reliable SHM system with
continuous monitoring, rugged enclosure, GPS
synchronization, and remote access
Products: LabVIEW and CompactRIO
“Using National Instruments hardware and software, we designed, prototyped, and
deployed a high-channel count, SHM system with GPS synchronization in less
than one-year.” - Chris McDonald, CGM Engineering
Monitoring the Structural Health of the Rion-Antirion
Bridge Using NI LabVIEW
Application: High-channel, mix-sensor
monitoring system distributed across 3-km
bridge in high-seismic activity
Challenge: Reliable, real-time monitoring while
subjected to harsh environmental and
seismic conditions
Products: LabVIEW and PXI
Key Benefit: Easy to mix and synchronize
different measurements within PXI system;
real-time, reliable monitoring systems with
LabVIEW Real-Time
Wireless Sensor Network Components
WSN Measurement
Nodes
Temperature
Dissolved
Oxygen
Host Controller
Radio
Battery
IEEE 802.3
Ethernet
Microcontroller
WSN Gateway
Analog Circuit
Voltage
Sensor Interface
Network Topologies
Star
Gateway
Router Node
End Node
Mesh
Cluster/Tree
Distance
Reliability
Complexity
Latency
Wireless Standards
Power Consumption,
Cost, and Complexity
High
Low
(Battery)
Cellular
WLAN
IEEE 802.11
Wi-Fi
Transmission
Distance
Long
WPAN
Bluetooth
Medium
Short
ZigBee
IEEE 802.15.4
100 k
1M
10 M
Data Rate (b/s)
100 M
IEEE 802.15.4/ZigBee
• Popular for WSN devices
• IEEE 802.15.4 defines:
868, 915 MHz, and 2.4 GHz
radios
ƒ Up to 250 kb/s
ƒ Low-power communication
ƒ
• ZigBee adds:
Device coordination
ƒ Network topologies
ƒ Interoperability with other wireless
products
ƒ
Application Layer
Application Support
Data service and management
ZigBee Device Objects
Device coordination: gateway, router, or
end device
Application Framework
User Profiles
Network Layer
Routing, Network Topologies, and Security
Medium-Access Control Layer
Physical Layer
868 MHz/915 MHz/2.4 GHz
IEEE 802.15.4
ZigBee
Power Considerations
• Nodes sleep most of the time to conserve power
• Must minimize processor and radio power
Node Power
Consumption
Time
Microprocessor Trends and Options
Power Consumption
Example
On
Sleep
Bits
Processor
Speed
TI MSP430 F2419
8 mW
0.2 µW
16
8 MHz
128 KB
Freescale QE128
100 mW
1 µW
8/32
50 MHz
128 KB
ARM
OKI ML674K
145 mw
50 µW
16/32
33 MHz
512 KB
PPC
Freescale MPC8313
520 mW
300 mW
32
333 MHZ
GB External
x86
Intel Core 2 Duo T7400
34 W
12 W
64
2.16 GHZ
GB External
Crossover
Embedded
Memory
Low-Power. Reliable.
NI Wireless Sensor Networks
NI WSN-9791
Ethernet Gateway
•
•
•
2.4 GHz, ZigBee-based radio
Ethernet connectivity to Windows
or Real-Time OS host controllers
Easy WSN configuration in
NI Measurement & Automation
Explorer
NI WSN-3202
NI WSN-3212
Measurement Nodes
•
•
•
•
•
•
•
4-channel, 16-bit, 0 to10 V analog input node
4-channel, 24-bit thermocouple input node
Easy access to I/O with NI LabVIEW project
integration and drag-and-drop programming
Low-power TI MSP430 processor
4 AA battery-powered, up to 2+ year lifetime
2.4 GHz, ZigBee-based radio
Screw terminals for sensor interface
Develop a WSN Measurement System
Database
Server
LabVIEW for
Windows
LabVIEW
Real-Time
IEEE 802.3 Network Backbone
Worldwide Web
Wireless
“Smart” Devices
WSN
Measurement
Nodes
WSN Gateway
Wireless Sensor Networks Demo
For more information, visit ni.com/wsn