1. An Introduction to Industrial Wireless Networking
Presented by
Yokogawa North America
Network Solutions Business Unit
February 2007

2. RF Wireless Industrial Applications

3. Industrial RF Wireless Technology Applications
Information Layer
Information Layer
HMI, Computer, Database Server
Control Layer
Recorder, Data Acquisition I/O, Controller, PLC
Device Layer
Transmitters, Sensors, Actuators
Control Layer
Device Layer

4. Industrial RF Wireless Technology Applications
Technology must support the Application
Considerations
Packet Size
Throughput
Response Time
Network Size
Our Focus
Info & Control Layers
2.4 GHz
Spread Spectrum Technology
802.11
Proprietary SS
Bluetooth
Zigbee

5. Control Layer Communications Protocols
Requirements
More throughput
Faster Response Time
Large Networks
More data
Typical Protocols
Modbus RTU
RS232, RS422, RS485
Modbus TCP
Ethernet
Proprietary TCP
Standard Ethernet
FTP
SMTP
SNTP
HTTP

6. Wireless – A Money Saving Solution$0
$5,000
$10,000
$15,000
$20,000
$25,000
$30,000
25'
50'
100'
250'
500'
1000'
Wireless - 1st Node
Wireless -2nd Node
Wireless - 3rd Node
Wire $20/ft
Wire $30/ft
Wire $50/ft
Wireless cost savings increase with distance & number of nodes

7. Wireless for Hazardous Locations
Wiring costs increase for tougher environments
Reduced operator costs
Clean rooms too!
UL Class I Div 2 approved radios

8. History of Wireless LANs
Wireless Networks were first developed by the Military
Eventually Moved to Private Sector
High Cost, Low Data Rate and Complexity prevented the widespread use
Used when other options weren’t possible
ALOHAnet developed at the University of Hawaii, was one of the first private wireless data networks
Turning Point - Late 1990s IEEE ratified B
Data Rates Increased
Hardware Cost & Availability
Performance similar to Wired Ethernet

9. RF
Radio Frequency
&
Power

10. Radio frequency spectrum is assigned by governments
Radio Frequencies
Radio frequency spectrum is assigned by governments
CB radio: MHz
FM radio: MHz
WiFi for PC’s: 2.4 GHZ
Licensed vs. Unlicensed bands
Licensed provides more power!
Two licensed frequency bands
400 MHz
900 MHz
3 unlicensed frequency bands in U.S.
ISM bands (Industrial, Scientific, Medical)
MHz
2.4 to GHz
5.725 to GHz (U-NII*)
*Unlicensed National Information Infrastructure

11. Lower Frequencies (i.e. 900 MHz have greater distance)
RF Propagation
Higher frequencies have higher data rates (bandwidth)
There is 1000 times more spectrum between 1-2 GHz as there is between 1-2 MHz.
RF waves lose power as they travel in the air
Higher frequencies lose power (attenuate) faster
RF waves attenuate as they pass through objects
Higher frequencies attenuate faster
Lower Frequencies (i.e. 900 MHz have greater distance)

12. Understanding Power in Radios
RF transmitter and receiver power is expressed in watts.
RF power can also be expressed in dBm (decibels relative to milliwatts)
dBm for RF power is useful when calculating radio system gains
(since other gains and losses from cables & Antennas are in dB’s)
The relation between dBm and watts can be expressed as follows:
Power(dBm) = 10 x Log10 Power(mW)
1 Watt = 1000 mW; PdBm = 10 x Log10(1000) = 30 dBm
100 mW; PdBm = 10 x Log10 (100) = 20 dBm
1mW: PdBm = 10 x Log10 (1) = 0 dBm
Power(mW) = 10(Power(dBm)/10)
15 dBm = 10 (15/10) = 10 (1.5) = 32 mW

13. A Table of mW to dBm

14. Understanding Gain Measurements
Antenna performance is primarily established by its gain. There are three common references used when defining gain in radios:
Gain referenced to a dipole antennae: dBd
Gain referenced to an isotropic source: dBi
Gain referenced to power in milliwatts: dBm

15. EIRP (Effective Isotropic Radiated Power)
EIRP is the effective power transmitted from the antenna.
EIRP = (power at transmitter) - (cable attenuation) + antenna gain
EIRP = Pout - Ct - Gt
Pout = output power of transmitter in dBm
Ct = transmitter cable attenuation in dB
Gt = transmitting antenna gain in dBi
Take the following example:
transmitter power out = Pout = 50mW
cable loss (attenuation) = Ct = 4dB
transmitting antenna gain = Gt = 6 dBi
convert transmitter power from mW to dBm
10 x log (50/10) = 17 dBm
EIRP = 17dBm - 4 dBm + 6 dBm = 19 dBm

16. A Quick Comparison: Office vs. Industrial
32 mW
200 feet indoors
0 C to 40 C
Plastic
Power
Distance
Operating
Temp
Construction
Mounting
500 mW
20 miles outdoor
-30 C to 60 C
Aluminum

17. Performance of 2.4 GHZ vs. 900 MHz
Typical Outdoors with Line of Sight
2.4GHz, 1W plus 6dB gain antennas 5 – 15 miles
900MHz, 1W plus 6dB gain antennas 15 – 25 miles
2.4GHz, 100mW plus 16dB antennas 10 – 40 miles
900MHz, 100mW plus 16dB antennas 20 – 60 miles
Typical Indoors in Congested Environment
2.4GHz, 1W 100 – 600 feet
900MHz, 1W 500 – 5000 feet

18. Spread Spectrum & IEEE
Spread Spectrum
&
IEEE Standards

19. Introduction to Spread Spectrum
Spread spectrum – a class of modulation techniques that spreads a signal’s power over a wider band of frequencies than is necessary for the information being transmitted
Benefits of spreading the signal:
signal is immune to unwanted noise / interference
coding and decoding allow simultaneous transmission of multiple signals within the same frequency band
provides inherent data encryption / security

20. Spread Spectrum Introduction - 2
Two main classes:
Frequency Hopping Spread Spectrum (FHSS) Random Hops to difference frequency. 1 MHZ band. More Secure proprietary interface.
Direct Sequence Spread Spectrum (DSSS) Hot Spot WIFI 22 MHZ band b, 11 Megabit
New modulation technique for higher data rates:
Orthogonal Frequency Division Multiplexing (OFDM) achieves 54MBPS
802.11g and a – Split byte and transmit pieces simultaneous.

21. Frequency Hopping Spread Spectrum

22. Spread Spectrum vs. Narrow Band
Wide bandwidth of spread spectrum make more immune to interference vs. narrow band signal shown in the center of the graph (Older Radios use narrow band)

23. IEEE Standards “Soup” HomeRF 2.0 Wi-Fi5 802.11g 802.11a HomeRF 802.11b
Bluetooth
IEEE specifies wired connection between radios and devices
IEEE specifies an over-the-air interface between a wireless LAN client and a base station or between two wireless LAN clients.

24. 802.11x WLAN “S-p-e-l-l-e-d Out”
1 or 2 Mbps transmission in the 2.4 GHz band
frequency hopping spread spectrum (FHSS) or direct sequence spread spectrum (DSSS)
Wi-Fi
Wireless Ethernet Compatibility Alliance (WECA) certification for b devices
802.11b (Current Offering)
11 Mbps transmission in the 2.4 GHz band
Only DSSS
Vendor access points not compatible

25. 802.11x WLAN “S-p-e-l-l-e-d Out” - 2
Up to 54 Mbps in the 5GHz U-NII band
300 MHz bandwidth indoor, OFDM
Orthogonal frequency division multiplexing (OFDM)
50m range at 11 Mbps
802.11g
54 Mbps speed extension of b in the 2.4 GHz band with OFDM
Backward compatible with b for <11 Mbps
Wi-Fi5 (Newer Technology)
Wireless Ethernet Compatibility Alliance (WECA) certification for a devices

26. 802.11x WLAN “S-p-e-l-l-e-d Out” - 3
802.11i (Incorporated into WIFI Standard)
Security Enhancements to
Encryption & Authentication
TKIP – Temporal Key Integrity Protocol – interim solution
AES – Advanced Encryption Algorithm – new hardware
802.1x Authentication Framework included in i
Authentication protocol (EAP-TTLS, LEAP)
Dynamic encryption key distribution method
Supported in Windows XP

27. 2.4 GHz Direct Sequence Spread Spectrum (DSSS) Channels
802.11b Wireless LAN
2.4 GHz Direct Sequence Spread Spectrum (DSSS)
Channels
11 US, Canada
13 Europe
14 Japan
Data rates: 1, 2, 5.5, 11 Mbps (auto)
Signal level can cause lower data rate.
Access points, clients, bridges (Example Hardware)
Other notes:
Vendor Access Points do not generally communicate
802.11b and g clients will communicate
802.11a will not communicate with b/g

28. 802.11b Channels 1 1 2 3 4 5 6 6 7 8 10 9 11 11 12 13

29. 802.11 Access Points, Bridges and Clients
Wired Network
Access Point
Client (Station)
Coverage
Area
Access Point – Root Mode
Access Point – Repeater Mode
Ad hoc – no AP
Bridge or Access Point
in Bridge Mode
Bridge – Repeater Mode

30. Security
Security

31. Keep intruders out of your network
Wireless Security
Keep intruders out of your network
Authenticate users
Stop others from “sniffing” your data
Data encryption – proprietary or Wi-Fi Protected Access (WPA)
Minimize detection of your network
Turn off identifiers in beacon
Appropriate coverage area
Detect “rogue” access points
Wireless network maintenance software

32. 802.11 Wireless Security Data Encryption 1
WEP (Wired Equivalent Privacy)
RC4 based 40/128/256 bit keys
Key scheduling algorithm weaknesses
Wi-Fi Protected Access (WPA)
Solves weakness in WEP
Temporal Key Integrity Protocol - TKIP
Message Integrity Checking (MIC)
Extensible Authentication Protocol (EAP) / RADIUS
Authentication, authorization & accounting system

33. 802.11 Wireless Security Data Encryption 2
AES (Advanced Encryption System)
802.11i & new hardware
Symmetric 128 bit block data encryption
Will be supported in a few months.
Other Steps
– remove SSID from beacon
MAC ID white list (Limit MAC Addresses)
Must Enable to Be Effective

34. Wireless Network Planning

35. Wireless Network Planning Overview
What questions should I ask to qualify the application?
How can I predict link performance? How do I test it?
Which antenna cables?
How high do the antennas need to be installed to clear this hill?
Which antennas? What’s a dBi?
Radio
What about interference?
Where can / should the antenna go?
Radio
How do I get terrain data?
X kilometers
Can this distance be covered?
What is meant by line of sight and why is the Fresnel Zone important

36. Throughput and latency considerations
# bits of data x frequency sent
Add I/Os, PLC messaging, etc.
Repeater / master must be able to handle sum of remotes
Radio technology must fit or slow update rate / report by exception
Similar analysis to specifying PLCs
Throughput will determine update rate
Seconds to poll vs. hours

37. Radio coverage area

38. Radio Network Architectures: Point-to-Point
Point A
Point B
Point-to-point, stationary network easiest to design
Use directional antennas on both sides
Maximize signal strength
Minimize noise pickup
Must have line-of-sight between points
….but plan ahead if network will be expanded in the future
If Site A will be hub for additional sites, may need an omni or sector antenna
With less directional antennas, low noise at Site A – test
Can Site A “see” the future sites – or need additional height
Plan for bandwidth too – can radio at Site A handle 100’s of remotes?

39. Radio Network Architectures: Point-to-Multipoint
Hub site can be omni-directional or sectorized with multiple directional antennas – e.g. like slice of pie
Use sectors when more bandwidth is needed
Each sector antenna attached to radio on different hopping pattern or different b channel
Line-of-site more important – site survey
Hub site
Sector 1
(Ch. 1)
Coverage
Ares
Sector 1
(Ch. 11)
Sector 2
(Ch. 6)
Coverage
Area

40. Use of Wireless Repeaters
Use repeaters to:
Extend range of the wireless network
Avoid obstacles
For YLinx RLX-FH series
Use of repeater reduces bandwidth by factor of two - but does not decrease more for additional repeaters
For some radios bandwidth reduced by 1/# repeaters
Repeater on top of hill
or on one side to go
Around the hill
RLX
Link too long for
Repeater on top of hill
RLX
RLX
RLX

41. Information required to design wireless network and select accessories
Minimum information required to design all but the simplest systems
Number of sites today and planned
Location of sites & if indoor / outdoor
Drawing of building with scale and site locations and structure information
GPS coordinates or location on a drawing / topographic map with distances between sites to link
If device will move – show track / area where link is required
Structures where antennas can be placed and any rules on antenna structures (e.g. luxury living areas)
Protocol of devices to connect
Which devices need to communicate
Data throughput requirements for each node
Country radios will be installed
Any other radio systems in-use if known

42. Methods to collect application information
Verbal or electronic description of application from customer
Electronic drawings of buildings
Topographic maps showing site location and any obstructions or Topo USA type program
Electronic path study using digital elevation data and GPS coordinates of sites
Site review – visit site and physically inspect links
If very clear line of sight should not be an issue
High power strobe light for longer links - but visual LOS only
Test with RLX IF using same antennas and antenna locations
Complete site survey including RF noise analysis at key points

43. Handheld Spectrum Analyzer & 802.11 Analyzers

44. In-Building Site Survey
Building drawings
Construction materials
Metal interior walls?
Ceiling height
Equipment / product information
Coverage required
Fixed vs. mobile
If mobile – where?
Existing wireless infrastructure
Type / channels
Conduct site survey – walking plant and taking measurements
Signal-to-noise measurements with Ekahau Site Survey Tool

45. Topographical Maps

46. Outdoor – Computerized Path Studies
GPS coordinates
Digital terrain data
Paths feasible?
Antenna height
Repeaters? Location
Performance prediction
Redundant path analysis to support self-healing network capability
Blue - primary path
Red – back-up path
Black – path not available without increased antenna height

47. Example Wireless Outdoor Path

48. Site Survey – The Real World
“Shoot and scoot”
For less involved / shorter range installations
Bring radios, equipment and test links – if look good, finalize install
Formal site survey
Identification of all potential interference
Environment & radio – spectrum analysis
Collection of site data for each potential site
Geographical coordinates including elevation
Access roads, building code restrictions / solutions
Installation considerations – site preparation / building access, etc.
Nearby towers / structures for repeaters– access / rent
Power availability
Corroborate path study data with actual field measurements
Signal strength, throughput statistics, etc.
Identify man-made / tree height obstacles not evident from USGS data
We can provide site surveys ($1000 per day + plus per diam)

49. Selecting Antennas & Cables

50. Antennas (most) are passive – focus radio energy not amplify it
Antennas – The Basics
Antennas transform electromagnetic signals from transmission lines into electromagnetic waves (& vice-versa)
Antennas (most) are passive – focus radio energy not amplify it
Antennas work equally well transmitting or receiving RF energy
Electromagnetic waves from antennas have an E field and H field components
Polarization describes the orientation of the antennas electric field
Compare to narrowing beam of a flash light
Nozzle at the end of a hose – can narrow (and send water farther) or spread (cover more area) but total amount the same

51. High Quality, Low RF Loss Cables
Remote antenna placement requires lower loss RF cable to maintain system gain
Cable should be 50 ohm for RadioLinx impedance matching
Quality connectors, weather proofing, lightning protection
PoE and placing radio by antenna

52. Matching connector types
Common types
N-type
SMA
TNC
BNC
MMCX (PC card)
Matching connector types
Jack = threads on outside
Plug = threads on inside
So a jack will connect to a plug (if polarity matches)
Polarity
Standard polarity – plug has inner conductor pin
Reverse polarity – jack has the inner conductor pin
MMCX-Male
RP-TNC-Female
RP-TNC-Male
RP-SMA-Female
RP-SMA-Male
SMA-Female
N-Male
N-Female-Bulkhead

53. Configuring & Implementing Wireless Networks

54. Wireless Network Design Best Practices
Install antennas as high as possible
Avoid high gain omni-directional antennas (Harder to hit the target)
Design the system with a margin
10 dB minimum
20 dB if anticipate foliage growth
Use industrial routers in-front of wireless industrial Ethernet
Prevents LAN broadcast traffic from using RF bandwidth

55. Wireless Network Design Best Practices - 2
Put switch with IGMP snooping in-front of RadioLinx RLX-FH if multicast traffic – e.g. industrial Ethernet I/O messaging
After installation, test radio network before automation
Verify RF performance
Test throughput before & after automation added
Ethernet use ping or pathping (latter shows latency for each segment to identify bottlenecks)

56. RadioLinx Antenna Installation Notes
Avoid attaching antenna too close to buildings, towers, tanks, etc. to avoid reflections
Use side mount kits for at least 50 cm distance
Outdoor installations should be weatherproofed
At each cable splice
At antenna connection
Cable hangers / ties

57. Maintaining Wireless System Reliability
Changing environment
Inside the company – coordinate wireless networks / frequency uses
New equipment / infrastructure (metal walls)
Joes’s Neighborhood WISP now on your channel
Monitor performance for
Performance degradation / bottlenecks
Increasing throughput requirements
Increase ping latency
Re-transmit %
Monitor security

58. Wireless Network Monitoring Tools

59. Wireless Protocol Analyzer / Security Audit Tools
One differentiator is level of expert analysis to help sort through large number of packets
WildPacket AiroPeek, CommView WiFi, Packetyzer, Ethereal (Linux)

60. Application Examples
Application Examples

61. YLinx Frequency Hopping Ethernet (2.4GHz)
$1,581 per radio
Mobile configuration and data logging without wires!
Frequency hopping 2.4 GHz unlicensed (ISM band)
Not compatible with wireless (Wi-Fi)
Designed for industrial environment (-40 to 158 degF)
Up to 16 mile range with line of sight with hi gain antennas
Proprietary radio frequency protocol (158 hopping patterns)
40 or 128 bit hardware data encryption

62. YLinx Frequency Hopping Ethernet (2.4 GHz)
Data from Remote DX100’s is Consolidated in PC
PC running:
DAQStandard (configuration)
DAQLogger
SCADA/HMI with OPC
YLinx -FHE
DX104
RS232
MODBUS
RTU
Slave #1
YLinx -FHE
DX104
10BaseT
Ethernet
YLinx -FHE
RS232
MODBUS
RTU
Slave #2
YLinx -FHE
DX104
RS232
MODBUS
RTU
Slave #3

63. Product Samples: Ethernet Radio Modems
           
Product Samples: Ethernet Radio Modems
ELPRO 905U-D
MDS iNET900
YLinx RadioLinx
SCADALINK LANBRIGDE
900 MHz FHSS
900 MHz FHSS
2.4 GHz FHSS
900 MHz FHSS

64. Product Samples: Serial Radio Modems
           
Product Samples: Serial Radio Modems
Put serial devices on radio
SCADALINK SM900
Prosoft RadioLinx
2.4 GHz FHSS
900 MHz FHSS

65. YLinx Frequency Hopping Serial (2.4GHz)
$1,416 per radio
Mobile data logging without wires!
Frequency hopping 2.4 GHz unlicensed (ISM band)
Modbus RTU, Modbus ASCII, DF1, generic ASCII
RS232, RS422, or RS485
Flexible set-up modes
Point to point
Point to multi-point
Peer to peer
Designed for industrial environment (-40 to 158 degF)
Up to 16 mile range with line of sight with hi gain antennas
Proprietary radio frequency protocol (158 hopping patterns)
40 or 128 bit hardware data encryption

66. YLinx Frequency Hopping Serial (2.4 GHz)
Data from Remote DX100’s is Consolidated in DX200
YLinx-FHS
DX104
RS232
MODBUS
RTU
Slave #1
10BaseT
Ethernet
YLinx-FHS
DA100
YLinx-FHS
RS485
MODBUS
RTU
Slave #2
RS232
MODBUS
RTU
DX220
YLinx-FHS
UT450
RS485
MODBUS
RTU
Slave #3

67. YLinx 802.11b Industrial Wireless Radio
$1,755 per radio
Mobile configuration and data logging without wires!
802.11b direct sequence spread spectrum radios
Can be implemented with a single radio!
2.4 GHz unlicensed (ISM band)
Compatible with standard PC wireless cards
Designed for industrial environment
Up to 20 mile range in outdoor settings

68. UT351 with YLinx 802.11b Hotspot Laptop with 802.11b
“Wi-Fi” wireless ability
Laptop with b
“Wi-Fi” wireless ability

69. Typical Wireless Network
802.11b
wireless
802.11g
wireless
Linksys G Wireless Router
Radiolinx
CX1000
UT351
MX100
FA-M3 PLC

70. Wireless Ethernet Organizations
IEEE WLAN Working Groups
WECA
Wi-Fi Alliance
WLANA
Bluetooth
HiperLAN

71. Thanks!
Thanks!