Wireless Sensor NetworksAn Introduction to Technologies, Applications, and Architecture

Teppo MyllysDistrict Sales Manager, National Instruments

Agenda• Definition and Applications• Wireless Sensor Network System Components• Technology Considerations

Network TopologiesCommunication StandardsPower Consumption

• NI Wireless Sensor Networks• Develop a Wireless Sensor Network Measurement System

Wireless Sensor Networks (WSNs)

Applications include:• Environmental monitoring• Structural monitoring• Industrial machine monitoring• Power quality and consumption• Building and home automation• Health care• Asset monitoring

Defined as a wireless network that consists of spatially distributed devices that use sensors to monitor physical or environmental conditions

Structural Health Monitoring of the 2008 Olympic Venues in BeijingApplication: 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

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

Monitoring the Structural Health of the Rion-Antirion Bridge Using NI LabVIEW

Dissolved Oxygen

Wireless Sensor Network Components

IEEE 802.3Ethernet

BatteryBatteryMicrocontrollerMicrocontrollerAnalog CircuitAnalog Circuit

RadioRadio

WSN Gateway

WSN Measurement Nodes

Host Controller

Sensor InterfaceSensor InterfaceVoltage

Temperature

Network Topologies

Star MeshReliability

Latency

Cluster/TreeDistance

Complexity

Gateway

Router Node

End Node

Wireless Standards

Data Rate (b/s)

Pow

er C

onsu

mpt

ion,

Co

st, a

nd C

ompl

exit

y

100 k 1 M 10 M 100 M

ZigBeeIEEE 802.15.4

IEEE 802.11Wi-Fi

WPAN

WLAN

Low (Battery)

High

Bluetooth

Cellular

Short

Medium

Long

TransmissionDistance

IEEE 802.15.4/ZigBee• Popular for WSN devices• IEEE 802.15.4 defines:

868, 915 MHz, and 2.4 GHz radiosUp to 250 kb/sLow-power communication

• ZigBee adds:Device coordinationNetwork topologiesInteroperability with other wireless products

Physical Layer868 MHz/915 MHz/2.4 GHz

Medium-Access Control Layer

Network LayerRouting, Network Topologies, and Security

Application Layer

IEEE 802.15.4 ZigBee

Application FrameworkUser Profiles

ZigBee Device ObjectsDevice coordination: gateway, router, or

end device

Application SupportData service and management

Power Considerations• Nodes sleep most of the time to conserve power• Must minimize processor and radio power

Time

Node Power Consumption

Example

Power Consumption

BitsProcessor

SpeedEmbedded

MemoryOn Sleep

Crossover 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

Microprocessor Trends and Options

Low-Power. Reliable. NI Wireless Sensor Networks

• 2.4 GHz, ZigBee-based radio• Ethernet connectivity to Windows

or Real-Time OS host controllers• Easy WSN configuration in

NI Measurement & Automation Explorer

• 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

NI WSN-9791 Ethernet Gateway

NI WSN-3202 NI WSN-3212 Measurement Nodes

Develop a WSN Measurement System

IEEE 802.3 Network Backbone

DatabaseServer

LabVIEWReal-Time

LabVIEW forWindows

WSN GatewayWSN Measurement Nodes

Wireless “Smart” Devices

Worldwide Web

Wireless Sensor Networks Demo

For more information, visit ni.com/wsn