FIRE DEPARTMENT 800MHZ TRUNKED RADIO SYSTEMS
This file will take a look at 800T systems used by large FDs. by Peter Szerlag - August 1999
Definitions
Talkgroup - a grouping of radios on a trunked radio system (keep in mind that trunked radio systems can have a combination of conventional channels, simplex channels, and trunked channels)
Simplex channel - conventional - 1 frequency
Conventional channel - non trunked repeater channel (uses 2 frequencies - a input freq and an output freq)
Channel - a communications pathway
Frequency - a specific chunk of the radio spectrum
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AL - Huntsville
AL - Mobile
AR - Little Rock - apparently they go to a simplex channel at any major fire (8/99) - ?first major USA FD to go to 800T?
CA - Orange County - ?always go to simplex channels when inside canyons or large buildings - 15 frequency pairs support all fire units in the County (except for private and military units) - use conventional repeaters in canyons - ?only 1 portable radio per pumper - upgrading from analog to ?digital in September 1999
CA - San Diego - each rig has 4 radios - mobiles on 154Mhz and 800Mhz - portables on 150Mhz and 800Mhz - city is divided into 4 radio zones for fire calls - units responding to a fire call in a zone are assigned 2 talk groups per incident - 1 tactical and 1 command - each zone has only 1 command talkgroup - kinda loosely applied - all dispatch is done from 1 dispatch channel - all EMS calls are handled on 1 talkgroup - MDTs are used for relaying messages
CA - San Francisco - new system coming online in ?2000
CO - Denver - 2 ?talkgroups/?freqs are for talkaround??????
CT - Hartford - online ?1997
FL - Dade County - went to 800T for ?1 week in ?1997 then went back to old 453Mhz system
FL - Orlando - each onduty member has a portable radio - ?all units are dispatched via Channel 1 (the dispatch channel) - units arriving at emergencies are assigned a "Tac" talkgroup
GA - Atlanta - online in ?1997 - 6 transmitter sites - 22 freqs - ?12/95 first used - reportedly works well in buildings - all units are initially on Chl (the dispatch channel) - for EMS and minor fire calls, they switch to Ch2 when arriving at the scene - for building fire calls, the dispatcher will give the units a fireground channel when the first unit arrives at the scene - the fireground channel does not always have a dedicated dispatcher - Ch1 and Ch2 always have dedicated dispatchers/operators - fire units do not have Mobile Data Terminals (MDTs)
IN - Indianapolis - had a fire that killed ?2 firefighters - they could not activate the emergency buttons on their radios when wearing gloves - ?1993
KN - Lexington FD joining Univ of KN 800T system in ?2000 - FD will add 5 freq pairs to the system plus 5 backup channels
LA - New Orleans - online ?1997
MA - Worcester - 2 site system - FD has 1 simplex/direct freq for talkaround - PD and other city agencies have available 1 different simplex/direct frequency
MD - Baltimore - a 9 site system that is licensed for 4 transmit sites - each FD rig has 2 portables and 1 mobile radio
MI - Detroit - ?FD on 800T
MO - Kansas City - FD has had huge problems with this radio system - reportedly, 3 firefighters had to leap out of a window during a fire due to radio failure in ?1997
NC - Charlotte/Mecklenburg County - 1 primary site with ?20 channels plus 3 outlying sites with ?5 channels each
NV - Las Vegas - 8/99 - Las Vegas FD and Clark Co FD are sharing a new 16 channel system - ?PD still on 159Mhz - PIO sent out a news release to the news media about not confusin drills for real incidents (it was posted on Fire-L)
OH - Akron online ?1993
OH - Cleveland online 1998 - have suffered couple of random total system failures with failure of ?FailSoft also
OH - Columbus online ?1995
OH - Toledo online ?1993
OK - Tulsa - portables are only turned on when units are responding to calls - dynamic reallocation is used to put all units responding to a call on the same talkgroup - all onduty firefighters have a portable radio - (only 2 HTs per rig - 11/22/99)
OR - Portland
PA - Pittsburgh - on 800T for ?1 year - sysytem thrown away in ?1995 and public safety went to 453Mhz
TN - Memphis
TN - Nashville - online ?August 1999
TX - San Antonio - ?1 main site plus ?3 minor sites
WA - Seattle - initially, the radio system had 3 sites - when the PD joined the FD on the system in ?1995, ?1 more site was added and the system was upgraded to a Smart Zone system / simulcast system - 8/99 looking at the FCC database and the County 800T website, it appears that Seattle has either 5, 7, or 8 antenna sites now. The FCC data shows 5 transmit sites, but the County 800T website shows 7 or 8 sites.
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Most scanner/trunking websites contain no info about FD simplex channel useage. (8/18/99)
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