1. Public Safety Radio System System Overview

2. Frequencies vs. Channels
A frequency is a point in the radio spectrum
part of what describes a channel
A channel is a set of parameters that can include one or more frequencies, CTCSS tones, name, etc.
Example: VCALL10 is a channel with transmit and receive frequency MHz, CTCSS tone of Hz
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Radio System Overview
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3. Simplex Radio Channel Using 1 Frequency
Each User Must be Line of Sight with Each Other
Very Reliable
Limited Range
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4. Repeater Radio Channel Using 2 Frequencies
Frequency 1 Used to Talk from Radio to Base
Frequency 2 Used to Talk from Base to Radio
Each User Must be Line of Sight with Base
Enhanced Range
Frequency 1
Frequency 2
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5. Base Station – Simplex
Some units don’t hear transmission because of obstructions. Dispatcher relays message so it is heard by all units
Unit 1
Dispatch Center
Unit 2
Unit 3
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6. Base Station – Repeater
All units within range of repeater hear all transmissions through the repeater
Dispatch Center
Unit 1 f2 f1 RX TX
Unit 4
Unit 2
Repeater
Unit 3
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7. Type of Systems Single Site Everything Located at One Site
Multiple Site
Remote Receive Sites
Simulcasting
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8. Single Site Coverage limited to units within range. 2/22/2013
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9. Remote Receivers
Voter (comparator) chooses best received signal and sends that signal to:
Simplex - Dispatch
Repeater - Transmitter
Voter
Central Transmitter
Remote Site Link (microwave, phone line, etc.)
Users do not need to change channel depending on location. System (voter) automatically picks best receive tower site.
RX Only Site
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10. Simulcasting
The same information is transmitted on the same channel at the same time from multiple locations.
Central Transmitter
Remote Site Link (microwave, phone line, etc.)
Remote Site
Remote Site
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11. Radio System Centrally Located Tower
Radio transmissions to/from mobile units take place from this site.
Remote Receiver Sites to “Hear” Users
Fills in holes in system reception
Simulcast Paging Sites
Additional Radio Channels
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12. License Additional Channels
Emergency Management Repeater
Law Enforcement Repeater
Fire / EMS Repeater
Paging Repeaters
Two Scene Tactical Channels
Jail Operations Channel
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13. Base Sites Six Main Tower Locations Independence Tower
Aurora Water Tower
Rowley Water Tower
Fairbank Tower
Jesup Water Tower
Court House Tower
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14. Tower Layout
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15. Fire / EMS Operational Channels
PAGING
FIREOPS 1
Repeater, Main Dispatch / Operations Channel
FIREOPS 2
Simplex, Secondary Dispatch / Operations Channel
VFIRE21 (State Fire)
Simplex, Interoperability Channel
FIRETAC1 & FIRETAC2
Two On Scene Tactical Channels
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16. Law Operational Channels
LAWOPS 1
Repeater, Main Dispatch / Operations Channel
LAWOPS 2
Simplex, Secondary Dispatch / Operations Channel
LAW INFO
Simplex, Dispatch Information Channel
VLAW31 (Law Mutual Aid)
Interoperability Channel
CF LEA
Law Tactical Channels
LAWTAC A (Analog) or LAWTAC D (Digital)
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17. EMA / Roads Operational Channels
EM OPS
Repeater, Main Dispatch / Operations Channel
ROADS
JAIL OPS
Simplex, Dispatch Information Channel
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18. Interoperability Channels
Iowa Channel
VHF “VTAC” Channels
Surrounding Jurisdictions
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19. Aurora Site Channels Transmit (Tx) “Talk” Receive (Rx) “Hear” PAGING
LAWOPS 1
FIREOPS 1
FIREOPS 2
EM OPS
ROADS
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20. Fairbank Site Channels
Transmit (Tx) “Talk”
PAGING
Receive (Rx) “Hear”
LAWOPS 1
FIREOPS 1
FIREOPS 2
EM OPS
ROADS
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21. Jesup Site Channels Transmit (Tx) “Talk” Receive (Rx) “Hear” PAGING
LAWOPS 1
FIREOPS 1
FIREOPS 2
EM OPS
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22. Rowley Site Channels Transmit (Tx) “Talk” Receive (Rx) “Hear” PAGING
LAWOPS 1
FIREOPS 1
FIREOPS 2
EM OPS
ROADS
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23. Independence Site Channels
Transmit (Tx) “Talk”
PAGING
LAWOPS 1
LAWOPS 2
FIREOPS 1
FIREOPS 2
EM OPS
ROADS
Receive (Rx) “Hear”
PAGING
LAWOPS 1
LAWOPS 2
FIREOPS 1
FIREOPS 2
EM OPS
ROADS
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24. Court House Site Channels
Transmit (Tx) “Talk”
LAW INFO
VLAW31
VFIRE21
JAIL OPS
PT TO PT
CF LEA
VCALL10
UCALL40
8CALL90
UBUCLINK
Receive (Rx) “Hear”
LAW INFO
VLAW31
VFIRE21
JAIL OPS
PT TO PT
CF LEA
VCALL10
UCALL40
8CALL90
UBUCLINK
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25. Mobile Only Channels Transmit (Tx) “Talk” Receive (Rx) “Hear” CAR 2CAR
LAWTAC A
LAWTAC D
FIRETAC1
FIRETAC 2
REGMED
VMED28
Receive (Rx) “Hear”
CAR 2CAR
LAWTAC A
LAWTAC D
FIRETAC1
FIRETAC 2
REGMED
VMED28
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26. Channels With Best Coverage
Repeaters
PAGING
Hear from all tower locations. Talk from all tower locations.
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27. Channels With Best Coverage
Repeaters
LAWOPS 1
FIREOPS 1
EM OPS
ROADS
Simplex
FIREOPS 2
Hear from all tower locations. Talk from just Independence.
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28. Channels With Good Coverage
Repeaters
LAWOPS 2
Hear from just Independence. Talk from just Independence.
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29. Channels With Lowest Coverage
Simplex
LAW INFO
VLAW31
VFIRE21
JAIL OPS
PT TO PT
VCALL10
UCALL40
8CALL90
UBUCLINK
Hear from just Court House. Talk from just Court House.
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30. Things to Remember
With a Repeater, can see each other and may not be able to talk to each other.
The Repeater has to be able to Hear and Talk to both of you.
When this happens, switch to a simplex channel, FIREOPS2, FIRETAC, VFIRE.
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31. Things to Remember
With a Repeater, what you say will be head throughout the county.
With a Simplex channel you are heard only as far as the radio carries (Handheld shorter distance than a mobile).
Dispatch can hear the best with the towers and remote receive sites.
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32. Things to Remember
With a remote receivers, there will be cases that dispatch can hear you but can not talk to you.
Dispatch can hear better then talk due to remote receive sites. This was done to ensure handheld coverage.
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