copyright© 2013 adaptive wireless solutions ltd wireless sensor networks nick baker walter woods...
Post on 14-Dec-2015
221 Views
Preview:
TRANSCRIPT
Copyright© 2013 Adaptive Wireless Solutions Ltd
Wireless Sensor Networks
Nick BakerWalter Woods
Adaptive Wireless Solutions Ltd
Copyright© 2013 Adaptive Wireless Solutions Ltd
Adaptive Wireless Solutions• Specialists in monitoring and control solutions using wireless mesh sensor
networks for over 8 years
• Offer systems integration and equipment supply for numerous wireless and wired technologies driven by customer requirements
• Distributor for ECOMM and Wireless Sensors in UK and Europe • Certified System Partner for HMS Industrial Networks (Netbiter) in UK
• Can help you integrate and manage your data gathering, monitoring and control activities – Complete solution design, supply and support– Wireless technology consulting and advice– Programme and project management– Technical and wireless architecture design – Equipment and software supply from multiple vendors– Integration with other systems– Installation and commissioning– Maintenance and Support
Copyright© 2013 Adaptive Wireless Solutions Ltd
Customers and Projects
• Mesh Wireless projects in BMS extension, energy management, industrial plants, IT environments, commercial offices, universities and colleges, hotels and apartment complexes, warehousing, recycling plants, food companies and national utilities.
• Customers in UK, Ireland, Italy, Netherlands, Belgium, Hungary, Israel, Saudi Arabia
BOMBARDIER
Copyright© 2013 Adaptive Wireless Solutions Ltd
Business Advantages of Mesh Radio
Economic and operational advantages vs. wired sensors
• Up to 90% lower installed costs– Lower cost of required equipment and supplies– Much quicker installation = less on-site time and less disruption
• Monitor and control in:– harsh environments (lots of metal and interference)– “wire unfriendly” situations where wires are difficult or undesirable
• Low cost and speedy retrofit to existing buildings, equipment and processes
• Monitors mobile or rotating equipment• Easy optimisation of sensor position in process for a better result• Cost-effective diagnostics in uncertain or temporary situations • Multiple sensor types with standard wireless nodes on a single network• Remote, ‘PC-less’, monitoring from anywhere on the internet
Copyright© 2013 Adaptive Wireless Solutions Ltd
Wireless Network Types
Direct Connection– Wire replacement– Point to point, highly specific– Engineered to suit application
Star– One central routing and control point– Single-hop - point to multi-point– All data flows through central point
Mesh– Multiple data paths– Multi-hop– Can operate as star or hybrid star/mesh– Self configuring, self healing– Highly flexible, highly reliable
Gateway
Mesh node
Sensing
node
Older, less flexible, less reliable technologies
Newer, more flexible, more reliable technology
Copyright© 2013 Adaptive Wireless Solutions Ltd
Operational Advantages of Mesh
• Multiple Pathways– Stronger connectivity – Self-Healing, Self-Managing
• Transmit Around Equipment– More robust– More flexible
• Extend Network Range– More robust– More capable
Primary
Secondary
Out of Range
Primary
Copyright© 2013 Adaptive Wireless Solutions Ltd
Core Mesh Wireless Product Ranges
System Monitor/Inputs
Control/ Outputs
Key Strengths
ECOMM Yes Yes Large scale networks, multi-channel I/O, direct equipment/meter integration
Wireless Sensors
Yes No External TRH sensors, RTD’s, battery operation, device packaging
Copyright© 2013 Adaptive Wireless Solutions Ltd
ECOMM direct integration with Modbus meters
• The following electricity meter types are currently supported by direct integration via Modbus RS485 connection to the ECOMM WC21 radio unit– Schneider E 5600– Schneider ION 8600– Schneider PM 710/750– Schneider PM 9C– Schneider ION 6200– Carlo Gavazzi EM24– Veris H 8036– EIG Shark 100– Continental Controls Wattnode
• Other meter types can be added as needed (at a modest cost)
Copyright© 2013 Adaptive Wireless Solutions Ltd
Solution Architecture – Netbiter remote monitoring
Typical Sensors and I/O devicesBattery and/or line poweredTemperature sensorTemperature and humidityOccupancy, door contactLightPulse countingDry contact inputsUp to 32 inputs per radio: contact, NTC, 0-5V, 0-20mARelay and analogue outputsMulti-stage thermostat controllerModbus RTU bridge
Wireless mesh Gateway
Netbiter is Modbus TCP proxy
Wireless range to cover large sites, highly reliable digital mesh radio, not affected by interference. Scales from 1 to 100’s of points. Netbiter transfers data off-site to Netbiter Argos remote monitoring portal. Web API available to integrate data to other applications
Remote off-site monitoring using Netbiter Argos
Copyright© 2013 Adaptive Wireless Solutions Ltd
Although we specialise in mesh radio we also use
GSM/GPRS and Narrowband radio systems
when needed to meet customer requirements
Copyright© 2013 Adaptive Wireless Solutions Ltd
Example ProjectsIntegration type Sector DescriptionOPC / Remote Asset
ManagementSupermarket refrigerator, freezer temperature monitoring, HVAC and outside temperature monitoring. Expansion of trial site to 10 further stores
Modbus TCP / Remote Energy Electricity consumption monitoring on 7 floors of Dept. Health, London office, 8 meters per floor in risers. Wireless installed and commissioned in 2 days.
Modbus TCP into BMS Asset Management
Electricity feeder pillar status and generator status monitoring and control with battery UPS-protected wireless network across 100 acre government laboratory site.
Modbus TCP Building Management
Temperature and Humidity monitoring across 5 warehouses in large warehouse complex for Nestle
Modbus TCP/ BMS Building Management
Wireless temperature monitoring and window damper, heating valve and air recirculation damper controls. Historic university building. Demonstration project for Irish government.
BMS Energy Wireless boundary gas meters pulse transfer to BMS outstations on hospital site
Modbus TCP / SCADA Pharma Laboratory refrigerator, freezer and warehouse monitoring at Johnson & Johnson facility. Validated environment.
Direct I/O Asset Management
Remote generator status monitoring into site SCADA system
Copyright© 2013 Adaptive Wireless Solutions Ltd
Application example – Westfield Shopping Mall BMS integration for temperature control
55,000 Sq Metres on two floors with Atrium
49 Air handling units on
roof
1 Wireless network
18 Mesh repeaters
30 Sensing nodes
Ambient Temperature input to HVAC zone controls via Modbus
TCP
Installed in 2 days to resolve critical
operating requirement
£6,100 equipment cost
Copyright© 2013 Adaptive Wireless Solutions Ltd
Application example – Large Data Centre Monitoring Solution
Primary Server
Secondary Server
Remote Disaster Recovery Centre
Remote Business
Continuity Centre
Basement
Floor 1
Floor 2
Floor 3
Console
Control Room Viewers
OtherViewers
Secondary Console
CommonEthernet Network
Main Mission Critical Data Centre
7,500 Sq Metres
4 Floors
Phase 1 - 20086 Wireless Sub-
networks22 Mesh repeaters178 Sensing nodes
Ambient TRH
Phase 2 - 2009100 additional TRH
sensors on two floors
4 more wireless sub-networks
Phase 3 - 2010 Being planned now
Electrical PowerChilled water
Copyright© 2013 Adaptive Wireless Solutions Ltd
BMS / SCADA Integration
• We have supplied systems to clients providing integration to existing BMS’ and SCADA / software systems via:– Modbus TCP and RTU– Direct analogue and digital connection– ODBC, OPC and SQL connection
• BMS’ that have been integrated with our systems include:– Trend– Siemens– Schneider– Andover Controls/TAC– Honeywell– Priva
• Numerous SCADA systems have also been integrated
Copyright© 2013 Adaptive Wireless Solutions Ltd
Industrial Wireless Sensor Networks
Industrial WSN OEM Adoption Inhibitors
92%
67%
58%
53%
43%
20%
10%
0% 20% 40% 60% 80% 100%
Reliability
Standards
Ease of Use
Battery
Dev Cycles
Education
Node Size
Source: ON World, Inc.
Copyright© 2013 Adaptive Wireless Solutions Ltd
Building Automation Wireless Sensor NetworksCommercial Building WSN Adoption Inhibitors
70%
63%
55%
53%
52%
44%
23%
4%
0% 20% 40% 60% 80%
Reliability
Standards
Battery
Education
Dev Cycles
Ease of Use
Node Size
Guest Room
Source: ON World, Inc.
Copyright© 2013 Adaptive Wireless Solutions Ltd
Wireless Sensor Network Reliability
RF Interference
• Common interference sources:– Multipath interference
• Occurs when the RF signal interferes with itself• Reflections off surfaces of all types• Can interfere with original signal and even cancel it out
– Interference with other transmitters• ISM band 2.4 Ghz wireless is increasingly common• Signals can be affected by other sources• Data slows down (more retries) or even stops• A good way to avoid it is to ‘frequency-hop’
• Examples of other transmitters in the 2.4 GHz band can be WiFi nodes, microwaves, cordless phones, Bluetooth devices, RFID, and other wireless sensor networks.
• How can it be avoided?
T R
Copyright© 2013 Adaptive Wireless Solutions Ltd
Wireless Sensor Network Reliability
Interference Avoidance
• Typical methods:– Direct Sequence Spread Spectrum (DSSS) modulation
• Part of the IEEE802.15.4 radio standard• Spreads the signal over a wider bandwidth• Reduces the chance of blocking the whole signal
– Frequency-Hopping Spread Spectrum (FHSS) modulation• NOT part of the IEEE802.15.4 radio standard• Uses a range of base frequencies• Transmitter and receiver periodically hop to a new frequency• Acts more like a narrowband radio for very short intervals• Very unlikely that all channels in the band are interfered
– Dynamic channel hopping• Not a modulation technique• Enhances simple FHSS modulation by dynamically detecting
persistently busy channels and avoiding them
• The best mesh radio systems use all three techniques
TIME
FR
EQ
UE
NC
Y
frequency
Sig
nal s
tren
gth
2.40GHz 2.48GHz
NOISE FLOOR
INTERFERENCE
Copyright© 2013 Adaptive Wireless Solutions Ltd
Wireless Sensor Network Protocols
How do they affect performance?
• Two main options:– Carrier Sense Multiple Access
• Collision-based protocol• Uses collision-avoidance (CA) or collision detection (CD)• Most WSN protocols use CA to avoid network overhead• Network communication is not time-synchronised• Pseudo-random ‘Back-off and re-try’ mechanisms are used• Collisions within the network escalate as networks get larger• ZigBee is based on this CSMA-CA approach
– Time Synchronised Protocols• These minimise or avoid collisions and transmission re-tries• Time synchronisation allows the use of channel-hopping• TDMA (Time Division Multiple Access) is an example• Also called ‘slotted’ protocols because each device has a ‘time slot’
• The benefits of synchronised traffic and channel-hopping are:– Better performance (fewer collisions/retries)– Increased battery life (fewer retries)– Better interference avoidance (channel-hopping)
• The most sophisticated systems use adaptive dynamic channel-hopping
Copyright© 2013 Adaptive Wireless Solutions Ltd
Protocol Standards?
• There are many trade-offs in protocol design• There is room for several feature-specific protocol variants
using the IEEE 802.15.4 base standard• It is important that hardware remains 802.15.4 compliant• ‘Standard protocols’, if they ever become available, will not
mean that proprietary protocols become obsolete or unnecessary.
• ZigBee is not a standard and has serious reliability and performance limitations in industrial and commercial environments. ZigBee equipment from different vendors does not interoperate – one of the key goals of a standard.
IEE 802.15.4
PHY Layer
MAC Layer
MAC Layer
Data Link Layer
Network Layer
Proprietary Application
Application Interface
Application
• 802.15.4-based market offerings are differentiated by proprietary protocol stacks with different design goals
• Network layers of the protocol are not standardised
Copyright© 2013 Adaptive Wireless Solutions Ltd
Contact Details
Adaptive Wireless Solutions Ltd
91 High Street
Prestwood
Great Missenden
HP16 9ER
Tel:+44 (0) 1494 865992
www.adaptive-wireless.co.uk
Nick Baker
Director
Mobile: 07968 352875
nbaker@adaptive-wireless.co.uk
Skype: adaptivewireless
top related