How To Design A Wireless Radio System - IndustrialENET · Presentation OverviewPresentation...

How To Design A Wireless Radio System

Bringing Together Leading Brands in Industrial Automation

Presentation OverviewPresentation Overview

• Review Radio Basics• Initial Site Work• Using RF Design Program

• Site Example• Question and Answers


• Each Radio Application is Unique• Wireless is being applied in many

applications but few have a workingknowledge of designing a successfulwireless system

• Selecting A Wireless Vendor• Dizzying array ranges from vendors• Provide tools to personally review

specifications


• RF Design Program• Conservative model of expected radio

results• Allows for modification to system design

prior to installation if problems are found• Change Antenna Type• Change Coax Cable Types

• Provides means of determining expecteddata errors

RF Basics - Decibels (dB)RF Basics - Decibels (dB)

• Used for all mathematical calculations in theradio world.• dB is a logarithmic number

• dB =10 log (linear number)• A gain of 2 = 10 log (2) = 3 dB• A gain of 4 = 10 log (4) = 6 dB• When a number doubles it goes up 3 dB• When a number reduces by 1/2, it goes down -3 dB

• To multiply linear numbers you add logarithms• To divide linear numbers you subtract logarithms• Raise a linear number to the nth power, you

multiply its logarithm by n.• To take the nth root of a linear number, you divide

its logarithm by n.

RF Basics - Licensed FrequenciesRF Basics - Licensed Frequencies

• Common Licensed Frequencies• 72 to 76 MHz• 150 to 174 MHz• 400 to 420 MHz

• U.S.A. Federal frequency• Canada civilian frequency

• 450 to 470 MHz• 900 MHz

RF Basics - Unlicensed FrequenciesRF Basics - Unlicensed Frequencies

• Common Unlicensed Frequencies• 900 MHz Spread Spectrum• 2400 MHz Spread Spectrum• 5000 MHz Spread Spectrum

• Select Frequency of Operation• Based on site needs for data rate and

polling times needed

Licensed Narrow Band Radios Frequency Tx Power RF Data Rate Interfaces AB Protocol72 to 79 MHz 1 Watt 1.2 to 19.2 Kbps RS-232/422/485 DF1

150 to 174 MHz 1 to 40 Watts 1.2 to 19.2 Kbps RS-232/422/485 DF1400 to 420 MHz 1 to 40 Watts 1.2 to 19.2 Kbps RS-232/422/485 DF1450 to 470 MHz 1 to 40 Watts 1.2 to 19.2 Kbps RS-232/422/485 DF1

900 Mhz 2 to 4 Watts 1.2 to 19.2 Kbps RS-232/422/485 DF1

Spread Spectrum, Unlicensed RadiosFrequency Tx Power RF Data Rate Interfaces AB Protocol

900 Mhz .1 to 1 Watt 100 to 150 Kbps RS-232/422/485 DF12.4 GHz .1 to 1 Watt 100 to 171 Kbps RS-232/422/485 DF1

Ethernet, Spread Spectrum, Unlicensed Radios Frequency Tx Power RF Data Rate Interfaces AB Protocol

900 MHz .1 to 1 Watt .1 to 500 Mbps Ethernet Ethernet/IP2.4 GHz .1 to 1 Watt .1 to 11 Mbps Ethernet Ethernet/IP5 GHz .1 to 1 Watt .1 to 54 Mbps Ethernet Ethernet/IP

RF Basics - Radio TypesRF Basics - Radio Types

RF Basics - FeedlinesRF Basics - Feedlines

• Feedline• Pipeline for RF Energy From Radio to/from

Antenna• Different Cable Types Have Different Losses

• The lower the loss the more expensive the cable• Losses Based Upon Length & Frequency

• Expressed in dB/100 ft. by the manufacture• The higher the frequency, the more

attenuation in cables, connectors, etc.• All feedlines and connectors induce losses to

RF energy

RF Basics - Feedline Attenuation TableRF Basics - Feedline Attenuation Table

Frequency Band (MHz) 66 to 79 150 to 174 400 to 420 450 to 470 900 to 940 2400 to 2500 5100 to 5400

RG-58 2.5 5.2 8.4 9 13.7 n/a n/a

LMR 195 2 4.4 7.8 7.8 11.1 19 38

RG-8 (Solid) 1.1 1.7 2.9 3 4.5 7 14

LMR 600 0.547 0.964 1.72 1.72 2.5 4.42 7.3

3/8" Heliax 0.084 1.48 2.48 2.64 3.97 6.47 10.2

1/2" Heliax 0.463 0.88 1.36 1.45 2.17 3.52 5.5

7/8" Heliax 0.254 0.486 0.758 0.808 1.23 2.02 3.4

Feedline Attenuation (- dB/100 ft.)

RF Basics - Omni-Directional AntennasRF Basics - Omni-Directional Antennas

• Omni-Directional• Radiates RF energy in all directions from

antenna• Usually used at the Master and Repeater

Nodes

Top ViewRadiation Pattern

Vertical Polarization

360 degrees

Omni-directional AntennaVertical Polarized

Side ViewRadiation Pattern

Vertical Polarization

RF Basics - Directional AntennasRF Basics - Directional Antennas

• Directional (Yagi)• Radiates RF energy in one direction• Usually used at Remote Nodes in a Point to Multi-

point system or Point to Point Site

HorizontalBeam Width

(degrees)

Back Lobe

Top ViewRadiation Pattern

Vertically Polarized

3 dB Points

Side ViewRadiation Pattern

Vertically Polarized

Vertical BeamWidth

(degrees)

Back Lobe

3 dB Points

RF Basics - Antenna GainRF Basics - Antenna Gain

• As Antenna Gain increases AntennaPattern becomes more directional

• Antenna Gain is measured in decibels(dB) dBi vs dBd = - 2 dB difference forsame product (example: 10 dBi = 8 dBd)

• Effective Radiated Power (ERP) = TxPower + Antenna Gain - Feedline Losses

• Received Signal = Rx Power + AntennaGain - Feedline losses

RF Basics - Antenna PolarizationRF Basics - Antenna Polarization

• Vertical Or Horizontal Polarization• Polarization is the radiating element

referenced to earth• All nodes must be the same polarization

• Cancellation of signal if mismatched• Vertical Polarization for SCADA Radio

Applications

Directional AntennaVertical Polarized Omni-directional Antenna

Vertical Polarized

Minimum Antenna Height Requiredto Clear the Radio Horizon

Minimum Antenna Height Requiredto Clear the Radio Horizon

Earth

Antenna A Antenna B

MinimumHeight (ft.)

MinimumHeight (ft.)

Distance (miles)

Radio Horizon

Fresnel ZoneFresnel Zone• Fresnel Zone shows the ellipsoid spread of the radio waves• Area must be clear of obstructions or signal strength will be reduced• Blockage >40% will induce significant signal losses• Use for frequencies above 1000 MHz

RF Basics - Fade MarginRF Basics - Fade Margin

• Receiver Sensitivity is the minimum signal level in dBneeded by the receiver to output received data.

• Fade Margin in dB is the amount of received signalabove the receiver’s minimum required ReceiverSensitivity.

• Fade Margin is controlled by• Transmitter Power • Transmitter feedline attenuation• Transmitting antenna gain• Receiving antenna gain• Receiver feedline attenuation• Receiver Sensitivity

FeedlineAttenuation

LightningArrestor

Tx Power

Tx Antenna Gain

Effective Radiated Power

Rx Sensitivity

LightningArrestor

Rx Antenna Gain

Spreading Losses(Controlled by Nature)


FeedlineAttenuation

• How much Fade Margin?• Imperfect world and things go wrong.

• Equipment ages• Antennas go out of alignment• Unexpected man-made noise/interference

• Minimum of at least 3 dB abovebackground noise.

• Basic rules of thumb for digitaltransceivers.

• 10 dB - 10% link retries• 20 dB - 1% link retries• 30 dB - .1% link retries


Initial Site WorkInitial Site Work

• Draw a simple layout of the proposedsystem.

• Determine Line-of-Sight (LOS)distances between each point to pointradio path by:• Site maps.• If Latitude and longitude are known use the

“Distance Between Two Points Calculator”in the RF Design Program.

• Use a hand held GPS.

• All Radio Systems are a Series of Pointto Point Links• Base to Remote• Base to Repeater• Repeater to Remote• Repeater to Repeater

• Each Link Needs Evaluation



• Find the elevation of each node abovesea level.• Reference maps or use a hand held GPS.

• Estimate installed antenna height ateach node above ground level toachieve LOS to destination site.

• Estimate feedline length from antennato equipment cabinet.

• Sketch (LOS)blockages between nodeson the map.


Antenna

Feedline

EquipmentCabinet

Terrain Height AboveSea Level

Height of AntennaAbove Ground


• Calculate Elevation Differential between thelowest node and the remaining nodes.

• Calculated the Adjusted Antenna Height.• Site Elevation Differential + Antenna Height

above ground.

Name Site Elev. Elev. Dif. Ant. Hgt. Adj. Ant. Hgt. Feedline Lgh.Control Room 560 80 20 100 30Pump Site #1 570 90 20 110 30Pump Site #2 820 340 20 360 30Water Tank 1100 620 120 740 130Pump Site #3 480 0 20 20 30

Site Information

Calculate ElevationDifferential betweenlowest node andremaining nodes.

Adjusted Antenna Height =Elevation Differential +Antenna Height aboveground.


N

Pump Site #2

Control Room

Pump Site #1

Water Tank

Pump Site #3

Site Layout Map and InformationSite Layout Map and Information

LOS

LOSLOS

LOS

Name Site Elev. Elev. Dif. Ant. Hgt. Adj. Ant. Hgt. Feedline Lgh. Ant. TypeControl Room 560 80 20 100 30 Omni-Dir.Pump Site #1 570 90 20 110 30 DirectionPump Site #2 820 340 20 360 30 DirectionWater Tank 1100 620 120 740 130 Omni-Dir.Pump Site #3 480 0 15 15 30 Directional

Site Information

4 miles

5.5 miles

5 miles

3 miles

9 miles

LOSLOS

RF Site Design ProgramRF Site Design Program

• Use the RF Site Design Program oneach point-to-point RF path.• In this example Customer wants high

speed Ethernet for their site.• Control Room to Pump Site #1

• Use your Site Information Table data• Use Vendor information on transceiver selected.

• The RF Site Design Program will provideESTeem hardware recommended for operatingfrequency selected.

• Enter data in the Data Entry Key Board.

N

Pump Site #2

Control Room

Pump Site #1

Water Tank

Pump Site #3


LOSLOS

LOS


Site Information

4 miles

5.5 miles

5 miles

3 miles

9 miles

LOSLOS

Control Room to Pump Site #1Control Room to Pump Site #1


Site Information

• Enter data into the keyboard

RF Path AnalysisRF Path Analysis

Control Room to Pump Site #1

N

Pump Site #2

Control Room

Pump Site #1

Water Tank

Pump Site #3


LOS

LOS

LOS


Site Information

4 miles

5.5 miles

5 miles

3 miles

9 miles

LOSLOS


Control Room to Pump Site #2

N

Pump Site #2

Control Room

Pump Site #1

Pump Site #3


LOS

LOS

LOS


Site Information

4 miles

5.5 miles

5 miles

9 miles

LOSLOSWater Tank

3 m

iles


Control Room to Water Tank

N

Pump Site #2

Control Room

Pump Site #1

Pump Site #3


LOS

LOS

LOS


Site Information

4 miles

5.5 miles

5 miles

9 miles

LOSLOSWater Tank

3 miles

LOS


Pump Site #2 to Water Tank

N

Pump Site #2

Control Room

Pump Site #1

Pump Site #3


LOS

LOS


Site Information

4 miles

5.5 miles

5 miles

9 miles

LOSLOSWater Tank

3 miles

LOS

LOS



• Problem areas• Fresnel Zone Warning

• Increase height of the Pump Site #3 Antenna• Need to increase from 15 ft. to 33 ft. to be above the minimum

height requirements for the Fresnel Zone.• In this example I increased height to 40 ft. for a margin of error.• Increased feedline to 55 ft. due increased antenna height.

• Note the increased attenuation of the feedline made the FadeMargin decrease from .8 dB to -.1 dB after raising the height.Now the path is not operational.

• This is the best that we can do for antenna height and keepfeedline length as low as practical.



• Problem areas• Fade Margin = -.1 dB. RF Path Not Operational

• Water Tank Node• Move the radio closer to the antenna

• 130 ft. of Helaix has 4.6 dB attenuation• 30 ft. of Helaix has 1.1 dB attenuation

• Fade Margin = 3.4 dB with 30 ft. of hHeliax• RF Path is now operational.

• Decreasing feedline losses increases Fade Margin



• Problem areas• Fade Margin = 3.4 dB. RF Path Operational

• Reduce the RF data rate from 11 to 5.5 Mbps• Receiver Sensitivity is now 87 dBm

• Fade Margin = 8.4 dB

• For more Fade Margin reduce data rate to 1 Mbps• Receiver Sensitivity is now 94 dB

• Fade Margin = 15.4 dB



• Special Feature of the Model 192E• 192E will Auto Scale the RF data rate from 1

to 11 Mbps based on environmentalconditions.

• Reducing the RF data rate increases theReceiver Sensitivity.

• Increased Receiver Sensitivity will increaseFade Margin.

N

Pump Site #2

Control Room

Pump Site #1

Water Tank

Pump Site #3


LOS

LOSLOS

LOS


Site Information

4 miles

5.5 miles

5 miles

3 miles

9 miles

LOSLOS

N/A

Model 192E Maximum RangeModel 192E Maximum Range

• Two Directional Antennas• 12 dB Gain Each

• 25’ Coax Cables• 2 dB Loss

• Outdoor Installation• Lightning Arrestor and Jumper Cable

Distance = 96.8 miles @ 1 M bps - 0 dB Fade MarginDistance = 24.3 miles @ 11 M bps - 0 dB Fade Margin

• Antenna Height Required for 96.8 Miles = 1172 ft.• Height at both ends

• Fresnel Zone at 96.8 Miles = 277 ft.• 60% Fresnel = 136 ft.

• Total Antenna Height Required with 60% FresnelZone Requirement for Distance = 1241 ft

• Application is only Mountain Top to Mountain Top

Model 192E Maximum RangeModel 192E Maximum Range

ConclusionsConclusions

• Education is Best Means to Confidence• Reliability is only as good as the system

design• Use the Tools

• Compare different vendor’s hardware• Review specifications and claims

• Radio Applications Are Not Difficult• Planing and evaluation are best keys to

success

Factory TrainingFactory Training

• EST provides training, at no-charge, for a two daytraining class that includes:

• Product Overview• Programming Basic & Advanced Features• Interfacing & Modes of Operation• Antenna Selection• System Troubleshooting• System Design & Setup

Additional Questions?Additional Questions?

• Visit the ESTeem Booth• Sign-Up Sheet for RF Design

Program on CD• Web Site - www.esteem.com• Call Customer Support at

509-735-9092Return to CD Menu

How To Design A Wireless Radio System - IndustrialENET · Presentation OverviewPresentation...

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