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KALAMAZOO COUNTY FIRE 800 MHz VS VHFROE-COMM, INC
RICK HOCHSTEDLER
Agenda◦ 800 MHz vs VHF Solution Feature/Benefits
◦ Compare 800 MHz vs. VHF MHz Propagation Characteristics
◦ VHF Existing System Coverage Maps
◦ 800 MHz Existing Coverage System Maps
◦ VHF & 800 Proposed Coverage
◦ High Level Budgetary Comparison for both designs
◦ Conclusions
800 vs VHF Features
800 MHz Advantages
◦ Trunked System
◦ More Efficient Spectrum Use
◦ Ability to divide traffic through Talkgroups rather than Frequencies
◦ Exclusive Use Channels
◦ Limited Interference
◦ Excellent Protection and Ease of System Design
◦ Interoperability with Law Enforcement in surrounding counties like Van Buren, Kalamazoo, Calhoun & Barry Counties
◦ Recurring Fees in lieu of System Maintenance Responsibility
VHF
◦ Conventional Channels utilizing Existing Equipment
◦ Paging is currently available
◦ Mutual Aid for Fire with Surrounding Counties all VHF and will most likely stay VHF in St Joseph, Calhoun, Barry, Allegan, Branch with existing investment and limited 800 MHz Coverage
◦ System Maintenance and Control in lieu of Recurring Cost
Key Benefits 800 vs VHF
Portable & Pager Coverage800 or VHF Mobile Coverage – Not here to discuss Mobile coverage for either 800 MHz or VHF
Primary Reason for Discussion is Portable and Pager Coverage for 800 MHz and VHF
◦ MPSCS System was designed to provide 90% Coverage in the State of Michigan for Standard Mobile
◦ We all Agree that the MPSCS System can provide Mobile coverage
◦ Concerns and Reason for Discussion is Portable and Pager Coverage
◦ Fire relies on Portables & Pagers to Alert First Responders of Events
◦ Radio/Receiver/Pager must work inside buildings where first responders work, live and play
◦ Portable and Pager Talk Out is Highest Priority
◦ Once on Scene NFPA recommends all traffic should be analog and radio to radio
◦ Digital traffic can mask impending coverage issues
◦ Traffic through a wide area system requires that the portable reach out of fire scene to fixed site and repeated audio must make its way back to site and subscriber
VHF vs 800 MHz Propagation Characteristics
Radio Propagation Refresher
◦ System Components – VHF vs. 700/800 MHz
◦ Transmitters
◦ Receivers
◦ Transmission Line, Filters & Combiners
◦ Antenna Performance
◦ Interference
◦ Path Losses
◦ Free Space Loss
◦ Shadow Loss
◦ Diffraction, Reflection and Foliage
◦ Material Attenuation
◦ Walls, Windows, Body Loss & Other Man Made Objects
System ComponentsTransmitters
◦ 800 MHz vs VHF 100-110 Watts no relative winner
Receivers
◦ Both Receive signals of -118dBm no advantage
Transmission Line
◦ Loss is Greater at 800 MHz, Line Loss can be compensated for by larger feed lines and RX Amps
Filters & Combiners
◦ Loss is similar in both VHF and 800 MHz, no advantage
Antennas
◦ Shorter wave length allows higher gain on 800 MHz, clear advantage 800 MHz
AntennasEfficient Antennas have lengths of 1 wavelength
◦ 150 MHz 1.6 Feet
◦ 860 MHz 3.4 Inches
Mobile Radio
◦ Both 800 MHz and VHF can achieve optimum wave length (Mobile Antennas @ ¼ Wave)
Portable Radio
◦ Quarter Wavelength antenna not practical at 150 MHz
◦ VHF Gain will be less than 800 MHz Portable (Favors 800 MHz by 10 dB)
Repeater Sites
◦ VHF 5-6 dB Gain 20’ Antenna Length
◦ 800 MHz 10 dB Gain 13’ Antenna Length
Interference (Repeater Sites)VHF
◦ Co-Channel minimum separation between RX and TX
◦ Co-Site highly variable, depends on quality of site, co-location and protections or filters installed
◦ No Duplex band, difficult to isolate TX and RX on Repeaters
◦ Lots of Interference Sources in VHF
700/800 MHz
◦ Co-Channel, somewhat variable, many exclusive use channels in use
◦ Co-Site highly variable, depends on quality of site and co-location and protections installed
Summary:
◦ System design is most important, VHF tends to have more interference and requires additional planning, filtering and design consideration
Free Space Loss vs. FrequencyFSL is Proportional to Frequency Squared
◦ Double Frequency = 6 dB more loss
◦ 800 MHz vs VHF 14.5 dB more loss or reduced range factor of 5.3
Path Loss Summary◦ VHF Wins by 14.5 dB
Diffraction Losses Favor VHF◦ Theory and measurements support this
Attenuation Losses Favor VHF◦ Construction Materials, Foliage, Walls etc.
Exceptions◦ Fresnel Zones on Line of Sight (800 MHz is shorter wave length with reduced Fresnel Zone)
◦ Apertures (Windows & Openings in Buildings) smaller wave length wins
Net Difference800 MHz vs. VHF Fixed Site, Same Height, Same Power Similar Antenna Gain
VHF Mobile vs 800 MHz Mobile
◦ VHF Mobile wins by 18.6 dB
◦ Same Site 800 vs. VHF, VHF Mobile -80 dBm, 800 MHz Mobile -98.6 dBm
VHF Portable vs 800 MHz Portable
◦ VHF Portable wins by 8.6 dB (18.6 dB – 10 dB Portable Antenna Loss)
◦ Same Site 800 vs. VHF, VHF Portable -90, 800 MHz Portable -98.6
Replicating VHF Coverage with 800 MHz
◦ Can be expensive
◦ Site Density should be greater on 800 MHz
800 MHz vs. VHF Site DensityA good rule of thumb for fire paging and portable coverage is 6-7 Mile Radius per Site
Site Density determines in building coverage.
VHF Coverage PredictionsComstudy 2.0
◦ Land use enabled
◦ Propagation Study accounts for Rural Agricultural Land, Forest, Urban Use
◦ 6db loss for VHF Portable & Pager Antenna Efficiency
◦ Assumes portable in hand outside buildings at 3-4’ height
◦ -90 dBm talk-out
◦ -95 dBm talkback
◦ 90% Confidence, predicts that coverage will be equal to or greater than predicted strength in 90% of the area 90% of the time.
Existing VHF Talk out Repeater -90dBmSingle Site VHF 100 Watt Repeater at 240’ Antenna Height
West Michigan Tower Existing Repeater Coverage Non-Simulcast
Existing VHF Portable Talkback -95dBmExisting 7 Site Voted Receiver
Alamo, Gull Road, Richland, Climax, Vicksburg, West Michigan and Westwood Tower Sites
Existing VHF All Sites Talk out to Portable -90 dBm7 Site Overlay Coverage, Non-Simulcast, unrealistic view of coverage
Used to show overlap and contiguous coverage if all sites could TX at same time
Proposed 7 Site Simulcast VHF Portable Talk out -90dBmCoverage is representative of 7 site design using all existing and or proposed sites available to Kalamazoo County
Approximate Cost of 7 Site Simulcast Solution <$1,000,000 assuming use of existing towers and relocation of voter and simulcast head end to Ravine or West Michigan Tower.
Solution would include Microwave to all sites with exception of Alamo, T1 circuit would be required to Alamo unless moved to higher ground
Proposed 7 Site VHF Simulcast Portable Talkback -95dBmPortable Talkback for VHF Simulcast 7 Site System
800 Coverage PredictionsComstudy 2.0
◦ Land use enabled
◦ Propagation Study accounts for Rural Agricultural Land, Forestry, Urban Land Use
◦ 0db loss for 800 MHz Portable Antenna Efficiency
◦ Assumes portable in hand outside buildings at 3-4’ height
◦ -100 dBm talk-out
◦ -105 dBm talkback
◦ 90% Confidence, predicts that coverage will be equal to or greater than predicted strength in 90% of the area 90% of the time.
800 MHz Existing Talk out -100 dBmCoverage is based on existing 800 MHz sites located throughout West Michigan, including sites located outside of Kalamazoo County
Existing 800 MHz Portable Talkback -105 dBmCoverage is based on existing 800 MHz sites located throughout West Michigan, including sites located outside of Kalamazoo County
VHF vs 800 MHz Single Site Coverage ComparisonComstudy 2.0
◦ Land use enabled◦ Propagation Study accounts for Rural Agricultural Land, Forestry, Urban Land Use
◦ 0db loss for 800 MHz Portable Antenna Efficiency
◦ 6dB loss for VHF Portable Antenna
◦ Assumes portable in hand outside buildings at 3-4’ height
◦ -100 dBm talk-out 800 MHz
◦ -105 dBm talkback 800 MHz
◦ -90 dBm talk-out VHF
◦ -95 dBm talkback VHF
◦ 90% Confidence for Both Maps
◦ VHF Fixed Site Adams Park/Vicksburg at 180’ AGL
◦ 800 MHz Fixed Site Adams Park/Vicksburg at 330’ AGL
800 MHz Adams Park Talk out -100 dBmAntenna Height is 300’+ AGL
Overlaid Radials represent 5 mile intervals
Coverage is based on -100dBm
VHF Adams Park Talk out -90 dBmAntenna Height is 180’ AGL
Overlaid Radials represent 5 mile intervals
Coverage is based on -90dBm
800 MHz Adams Park Talkback -105 dBmAntenna Height is 300’+ AGL
Overlaid Radials represent 5 mile intervals
Coverage is based on -105 dBm
VHF Adams Park Talkback -95dBmAntenna Height is 180’ AGL
Overlaid Radials represent 5 mile intervals
Coverage is based on -95 dBm
Budget for 800 MHz and VHF Designs
800 vs. VHF Budgetary AssumptionsAssumptions for 800 MHz
◦ Need additional coverage in Texas Township, Galesburg and Alamo
◦ Average Site Cost per Motorola is $1,000,000
◦ Assuming Existing Towers can be located in area where coverage is needed
Assumptions for VHF
◦ Use existing towers
◦ All Towers are Existing and Viable
◦ Relocate Voter and Upgrade to VHF Simulcast
◦ Upgrade All Sites including Emergency Power and Other Miscellaneous Site Improvements
◦ Install Microwave Point to Point and eliminate voice circuits and reliance on telco companies
800 MHz Investment to MigrateMany assumptions made with estimate based on traditional figures presented by vendors in design phase
Unit Ext.
Qty. Item Description Price Price
800 MHz Rought Estimate
Infrastructure:
3 Alamo, Texas Twp, Galesburg Sites 1,000,000.00 3,000,000.00
Assumption, Towers can be located, Motorola Estimate
$1,000,000 per 800 MHz Site on MPSCS System
Subscribers:
416 APX4000 Portable & Mobile 2,500.00 1,040,000.00
16 Departments @ 20 Radios Each
16 Departments @ 6 Mobiles Each
Pagers:
400 Unknown, Unavailable at this Time, Estimate $500??? 500.00 200,000.00
16 Departments @ 25 Pagers Each
System Investment: 4,240,000.00
VHF Investment to UpgradeEstimate is rough estimate, Design would require selection of head end site with suitable location for Voter and Simulcast Studio Equipment (Head end)
All existing portables, pagers and mobiles are compatible
Assumption that existing Output and Input Frequencies will be maintained
Unit Ext.
Qty. Item Description Price Price
VHF Simulcast Upgrade
Infrastructure:
7 Alamo, Richland, Climax, Adams Park, Schoolcraft, 80,000.00 560,000.00
W. Michigan, Ravine Rd, Estimate $80K per Site
for VHF Simulcast IP
Microwave:
7 Cambium 650 4.9 GHz PTP with Dish and 25,000.00 175,000.00
Equipment Located on Ground where Possible
Misc. Improvements:
1 Generators, Shelters, Electrical, UPS and Tower 250,000.00 250,000.00
Upgrades
System Investment: 985,000.00
Recurring Maintenance ComparisonsAnnual Fees vs. Infrastructure Maintenance on VHF Simulcast Infrastructure
800 MHz Recurring Fees
Unit Ext.
Qty. Item Description Price Price
Subscribers:
416 Portables and Mobiles on MPSCS Level B $100.00 $41,600.00
Assumption 16 Talkgroups $100/Yr.
Pagers:
400 Unknown
Single Department Alert
System Investment: $41,600.00
VHF Simulcast Infrastructure Maintenance
Unit Ext.
Qty. Item Description Price Price
VHF Simulcast Upgrade
Infrastructure:
7 VHF Sites at $60,000 Equipment/Site $3,000.00 $21,000.00
Microwave:
7 Cambium Dual Diversity 4.9 GHz Links Licensed $2,000.00 $14,000.00
Estimate $30,000 Equipment per Link
System Investment: $35,000.00
Conclusion 800 MHz vs VHF800 MHz
Investment $4 Million + for Site Density similar to Existing VHF System and Subscribers
Law enforcement would benefit by increased coverage and increased interoperability
Fire would increase wide area performance via Trunked System Operation and Ease of Segregating Traffic through Talkgroups
VHF
Investment less than $1,000,000 to Simulcast and Provide Adequate Coverage
Mutual Aid in Fire remains strong since all surrounding counties use VHF
Paging remains primary dispatch alert method