Date post: | 26-Mar-2015 |
Category: |
Documents |
Upload: | emily-williamson |
View: | 215 times |
Download: | 0 times |
ESTeem RF Design Tools
Presentation OverviewPresentation Overview
• Review Radio Basics– Terminology
• Use Information from Radio Basics and Antenna Sections
• Use RF Design Program– Initial Site Work– Using RF Design Program – Site Example
Presentation OverviewPresentation Overview
• Each Radio Application is Unique– Wireless is being applied in many applications
but few have a working knowledge of designing a successful wireless system
• Selecting A Wireless Vendor– Dizzying array ranges from vendors– Provide tools to personally review specifications
Steps to Successful Radio NetworkSteps to Successful Radio Network
• RF System Design– Review Maps– RF Design Program Analysis
• On-Site Radio Site Survey– Physical Inspection and Testing– Confirming Results from RF System Design
• Site Commissioning– Same Testing on Installed System
Presentation OverviewPresentation Overview
• RF Design Program– Conservative model of expected radio results\
• Installed hardware generally higher signal strengths
– Allows for modification to system design prior to installation if problems are found• Change Antenna Type• Change Coax Cable Types
– Provides means of determining expected data errors
Earth
Antenna A Antenna B
Minimum Height (ft.)
Minimum Height (ft.)
Distance (miles)
Radio Horizon
Directional Antenna
Omni-directional Antenna
Bottom Reference Line for Height Clearance
Minimum Antenna Height Required to Clear the Radio HorizonMinimum Antenna Height Required to Clear the Radio Horizon
• Fresnel Zone shows the ellipsoid spread of the radio waves
• Area must be clear of obstructions or signal strength will be reduced
• Blockage in 60% will induce significant signal losses
• Use for frequencies above 900 MHz
Fresnel ZoneFresnel Zone
RF Basics - Effective Radiated PowerRF Basics - Effective Radiated Power
• Effective Radiated Power (ERP) = Tx Power - Feedline Losses + Antenna Gain
• Received Signal = Rx Power - Feedline losses + Antenna Gain
RF Basics - Fade MarginRF Basics - Fade Margin
• Receiver Sensitivity is the minimum signal level in dB needed by the receiver to output received data.
• Fade Margin in dB is the amount of received signal above the receiver’s minimum required useable Receiver Sensitivity.
• Fade Margin is controlled by– Transmitter Power – Transmitter feedline attenuation– Transmitting antenna gain– Receiving antenna gain– Receiver feedline attenuation– Receiver Sensitivity Minimum Receiver Sensitivity
Maximum Received Signal Strength
Fade Margin = Usable Range of Receiver
• How much Fade Margin?– Imperfect world and things are constantly changing.
• Equipment ages• Antennas go out of alignment• Unexpected man-made noise/interference
– Basic rules of thumb for digital transceivers.• 10 dB - 10% link retries• 20 dB - 1% link retries• 30 dB - .1% link retries
– Link Listed Marginal <10dB• Over 10dB Fade Margin = Green• 1-10db Fade Margin = Yellow (Marginal)• Less than 1dB = Red (Site Not Operational)
RF Basics - Fade MarginRF Basics - Fade Margin
• Draw a simple layout of the proposed system.
• Determine Line-of-Sight (LOS) distances between each point to point radio 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.– Google Earth®
Initial Site WorkInitial Site Work
• Most Radio Systems are designed as a “Multiple” of Point to Point RF Paths– Base to Remote– Base to Repeater– Repeater to Remote – Repeater to Repeater
• Each Path Needs Evaluation
Initial Site WorkInitial Site Work
• Sketch a site diagram and distances between site nodes. Note LOS blockages.
N
Pump Site #2
Control Room
Pump Site #1
Water Tank
Pump Site #3
LOS
LOSLOS
LOS
4 miles
5.5 mile
s
5 miles
3 miles
LOSLOS
Initial Site WorkInitial Site Work
• Find the elevation of each node above sea level.– Reference maps or use a hand held GPS.– Google Earth®
• Estimate installed antenna height at each node above ground level to achieve LOS to destination site.
• Estimate feedline length from antenna to equipment cabinet.
Initial Site WorkInitial Site Work
Antenna
Feedline Length
Equipment Cabinet
Terrain Height Above Sea Level
Height of Antenna Above Ground for
LOS Path
Initial Site WorkInitial Site Work
• Calculate Elevation Differential between the lowest node and the remaining nodes.
• Calculated the Adjusted Antenna Height.– Site Elevation Differential + Antenna Height above
ground.
Initial Site WorkInitial Site Work
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 15 15 30
Site Information
Calculate Elevation Differential between lowest node and remaining nodes.
Adjusted Antenna Height = Elevation Differential + Antenna Height above ground.
Initial Site WorkInitial Site Work
Name Site Elev. Elev. Dif. Ant. Hgt. Adj. Ant. Hgt. Feedline Lgh. Ant. Type
Control Room 560 80 20 100 30 Omni-Dir.
Pump Site #1 570 90 20 110 30 Directional
Pump Site #2 820 340 20 360 30 Directional
Water Tank 1100 620 120 740 130 Omni-Dir.
Pump Site #3 480 0 15 15 30 Directional
Site Information
N
Pump Site #2
Control Room
Pump Site #1
Water Tank
Pump Site #3
4 miles
5.5
miles
5 miles
3 miles
LOS LOS
Site Layout Map and InformationSite Layout Map and Information
• Use the RF Site Design Program on each point-to-point RF path.– In this example we will use the ESTeem 195Eg– 2.4 GHz Frequency – Use your Site Information Table data– Use Vendor information on transceiver selected
• The RF Site Design Program will provide ESTeem hardware recommended for operating frequency selected
– Enter data in the Data Entry Key Board
RF Site Design ProgramRF Site Design Program
Standard Enclosure MountingStandard Enclosure Mounting
Lightning Arrestor
Ant
enn
a P
ort
Equ
ipm
ent P
ort
Directional Antennas
Omni-Directional Antenna
Coax CableESTeem
Model 195Eg
Power Supply
Model 195E Outdoor Pole MountModel 195E Outdoor Pole Mount
Model 195Eg
Omni-Directional Antenna
Model 195E Outdoor Fixed Base Hardware
Diagram
Direct Pole MountPole Mounting Kit EST P/N AA195PM
Power Over Ethernet Cable
Ethernet CAT-5e Cable 300 ft. maximum
Weather Proof Boot
Weather Proof Front Cover
Antenna Feedline
External Antennas
Directional Antennas
Weather Proof Boot
Weather Proof Boot
To LAN Interface
PoE Power Supply EST P/N AA175
Ethernet Surge Protection
EST P/N AA166
Ethernet CAT 5e Cable
EST P/N: AA09.2
Unit Shown With Rubber Duct Antennas
Direct Mount Antennas
Outdoor Mounting BenefitsOutdoor Mounting Benefits
• Remove Long Coax Cable Required– Lower cost ($65-$500 Savings) – Lower signal loss
• No Lightning Arrestor Needed– Lower cost ($120 Savings)– Also removes loss in jumper cable
• No Enclosure Needed– Greatly reduced design and installation costs ($300
Savings)
N
Pump Site #2
Control Room
Water Tank
Pump Site #3
4 miles
5.5
miles
5 miles
3 miles
LOSLOS
Perform a RF Path Analysis from the Control Room to Pump Site #1.
Name Adj. Ant. Hgt. Feedline Lgh. Ant. Type
Control Room 100 30 Omni-Dir.
Pump Site #1 110 30 Direction
Pump Site #1
RF Path AnalysisControl Room to Pump Site #1RF Path AnalysisControl Room to Pump Site #1
Name Adj. Ant. Hgt. Feedline Lgh. Ant. Type
Control Room 100 30 Omni-Dir.
Pump Site #1 110 30 Direction
Path Distance: 4 miles
RF Path AnalysisControl Room to Pump Site #1RF Path AnalysisControl Room to Pump Site #1
• In this example we used the highest Rx Sensitivity of -89 dB for a RF data rate of 1Mbps. This will give a 12.6 dB Fade Margin for a 4 mile path length.
• What would be the maximum data rate for this RF link?
RF Path Analysis Control Room to Pump Site #1RF Path Analysis Control Room to Pump Site #1
RF Output Power LevelsRF Output Power Levels
• Peak Power vs Average Power– Based upon type of modulation type– Maximum for peak power set by FCC/DOC
• Modulation– Average power and peak same in Direct Sequence – Maximum peaks in OFDM has lower average power
• Average power used in RF Design Program– Modulation type based upon data rate– Verify all RF data rates and power levels
RF Data Rate Analysis #1RF Data Rate Analysis #1
• Only available for wireless Ethernet products 195Eg, 195Ep and 195Ed• Enter site information same as RF Path Analysis• Fade margin results for each data rate
– Over 10dB Fade Margin = Green– 1-10db Fade Margin = Yellow (Marginal)– Less than 1dB Fade Margin = Red (Site Not Operational)
RF Data Rate Analysis #1RF Data Rate Analysis #1
• Maximum design data rate for application would be 9 Mbps• Maximum possible data rate is 18 Mbps• Actual Data Rates Could Be Higher in Normal Operation
– 195E will not reserve 10dB in operation– 195E will maintain highest data rate possible
• Same application using higher gain directional antenna
• AA204Eg 19dB Parabolic directional antenna
• Legal for use from single remote to omni-directional
RF Data Rate Analysis #2RF Data Rate Analysis #2
RF Data Rate Analysis #2RF Data Rate Analysis #2
• Much higher RF Data Rates available with higher fade margin• Maximum design data rate for application would be 24 Mbps• Maximum possible data rate is 48 Mbps
N
Pump Site #2
Control Room
Pump Site #1
Water Tank
Pump Site #3
Name Adj. Ant. Hgt. Feedline Lgh. Ant. TypeControl Room 100 30 Omni-Dir.Pump Site #2 360 30 Directional
4 miles
5.5 mile
s
5 miles
LOSLOS
Perform a RF Path Analysis from the Control Room to Pump Site #2.
24 Mbps
3 miles
RF Path AnalysisControl Room to Pump Site #2RF Path AnalysisControl Room to Pump Site #2
Path Distance: 5 miles
Name Adj. Ant. Hgt. Feedline Lgh. Ant. TypeControl Room 100 30 Omni-Dir.Pump Site #2 360 30 Directional
RF Path AnalysisControl Room to Pump Site #2RF Path AnalysisControl Room to Pump Site #2
RF Path AnalysisControl Room to Pump Site #2RF Path AnalysisControl Room to Pump Site #2
• Maximum design data rate for application would be 24 Mbps• Maximum possible data rate is 36 Mbps
Name Adj. Ant. Hgt. Feedline Lgh. Ant. TypeControl Room 100 30 Omni-Dir.Water Tank 740 130 Omni-Dir.
N
Pump Site #2
Control Room
Pump Site #1
Pump Site #3
4 miles
5.5 mile
s
5 miles
LOSLOSWater Tank
3 m
ile
s
Perform a RF Path Analysis from the Control Room to Water Tank.
24 Mbps24 Mbps
RF Path AnalysisControl Room to Water TankRF Path AnalysisControl Room to Water Tank
Path Distance: 3 miles
Name Adj. Ant. Hgt. Feedline Lgh. Ant. TypeControl Room 100 30 Omni-Dir.Water Tank 740 130 Omni-Dir.
RF Path AnalysisControl Room to Water TankRF Path AnalysisControl Room to Water Tank
RF Path AnalysisControl Room to Water TankRF Path AnalysisControl Room to Water Tank
• Maximum design data rate for application would be 9 Mbps• Maximum possible data rate is 24 Mbps
N
Pump Site #2
Control Room
Pump Site #1
Pump Site #3
Name Adj. Ant. Hgt. Feedline Lgh. Ant. TypeWater Tank 740 130 Omni-Dir.Pump Site #3 15 30 Directional
Site Information
4 miles
5.5 mile
s
5 miles
LOSLOSWater Tank
3 miles
Perform a RF Path Analysis from the Water Tank to Pump Site #3.
24 Mbps24 Mbps
9 Mbps
Water Tank to Pump Site #3Water Tank to Pump Site #3
Path Distance: 5.5 miles
Name Adj. Ant. Hgt. Feedline Lgh. Ant. TypeWater Tank 740 130 Omni-Dir.Pump Site #3 15 30 Directional
Site Information
RF Path AnalysisWater Tank to Pump Site #3RF Path AnalysisWater Tank to Pump Site #3
RF Path AnalysisWater Tank to Pump Site #3RF Path AnalysisWater Tank to Pump Site #3
• Maximum design data rate for application would be 24 Mbps• Maximum possible data rate is 36 Mbps
• 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.
Pole MountingWater Tank to Pump Site #3Pole MountingWater Tank to Pump Site #3
Model 195Eg Maximum RangeModel 195Eg Maximum Range
• Two Directional Antennas– AA204Eg is the highest gain antenna that the unit is type
accepted for.– 19 dB gain
• Cable Loss – .6 dB because the unit is pole mounted.
• Range– 179 miles @ 1 Mbps @ 6 dB Fade Margin– 8 miles @ 54 Mbps @ 6 dB Fade Margin
• Range– 179 miles @ 1 Mbps @ 6 dB Fade Margin
• Antenna Height = 4,010 ft at each end• Fresnel Zone (60%) = 185 feet• This would probably be usable only from mountain top
to mountain top– 8 miles @ 54 Mbps @ 6 dB Fade Margin
• Antenna Height = 54 ft. at each end• This is a practical height
Model 195Eg Maximum RangeModel 195Eg Maximum Range
• Two Omni-Directional Antennas– AA20Eg– 6 dB gain
• Cable Loss – .6 dB because the unit is pole mounted
• Range 6 dB with Fade Margin 1 Mbps = 9.0 miles @ minimum antenna height of 45 ft. 5.5 Mbps = 5.7 miles @ minimum antenna height of 36 ft. 11 Mbps = 4.0 miles @ minimum antenna height of 31 ft. 24 Mbps = 2.0 miles @ minimum antenna height of 26 ft. 54 Mbps = 0.4 miles @ minimum antenna height of 14 ft.
Model 195Eg Maximum RangeModel 195Eg 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