CFD UHF Tband? Why?

[lisalolo]

Why was the choice made for CFD to go to UHF t band... if I remember correctly in 2016 UHF T band public safety frequencies must be abandoned? Is that still the status quo?

[FFPM571]

because this system was in the works for almost 10 years prior to going live. Long before the federal mandate.Its not 2016 its 2023 I believe

[Chauffeur6]

As it currently stands, T-Band must be vacated no sooner than 9 years and no later than 11 years from February 2012. So, the reallocation process will begin in 2021 and be completed by 2023. That's still plenty of good years worth of operating on those frequencies.

Chicago seeks T-Band advice from the FCC -- Urgent Communications article | Policy content from Urgent Communications

T-Band Working Group

[zerg901]

Chicago PD uses UHF. Medic to hospital comms are on UHF. Probably makes sense for FD to use UHF also.

[mlmummert]

Originally Posted by Chauffeur6

As it currently stands, T-Band must be vacated no sooner than 9 years and no later than 11 years from February 2012. So, the reallocation process will begin in 2021 and be completed by 2023. That's still plenty of good years worth of operating on those frequencies.

Chicago seeks T-Band advice from the FCC -- Urgent Communications article | Policy content from Urgent Communications

T-Band Working Group

And if re-banding is an indicator, it will probably take place by 2053 or so.

[redburgundy]

Why did they decide to use conventional channels rather than a trunked system?
And why are some CFD channels still analog?
It seems like they're using six T-band digital channels, five T-band analog channels and six or seven non-T-band UHF analog channels.

[zerg901]

Maybe a trunked system would not be superior to a conventional system for CFD. Same as a trunked system apparently is not superior for the FBI. (related to channel loading - system coverage - cost of sites - costs of repeaters - etc)

Analog channels might work better for a fire department than digital channels due to high noise levels at fire incidents, the possibility of doubles, etc.

[redburgundy]

Are you suggesting that they did an analysis of trunked vs. conventional?
If so, has anyone seen it?

As a government agency, a study like that would have to be made publicly available, at least through a Freedom of Information Act (or whatever the local version is called) request.

[FFPM571]

Why dont you ask one of the OEMC techs he is on the board here.. There is really no need for a trunking system for CFD.. They have been using 2 dispatch for fire for 50 years and 2 dispatch channels for EMS for 40.. Thats what works for them. The firegrounds are analog

[redburgundy]

Longer than 50 years.
And adequate 95% of the time.
But listening to Radioman911's audio recording from the 4-11 yesterday, you can hear that the command van operator was unable to communicate with the incident commander on several occasions. Digital radios with Vehicle Repeater Systems in the Chief's buggies might have helped. Those might be conventional channels, of course.
But trunked systems also have some advantages.
When you have three or four working fires at the same time (admittedly not often), having them on separate talkgroups with separate dispatchers is preferable.
Even with only one major incident, having the staging area on a separate talkgroup from the operations talkgroup can be useful. In a high-rise fire, the vent group could be on a separate talkgroup.
You don't have rural water supply issues with non-hydranted areas in Chicago, but you do occasionally have "in-line" operations. In that case, a separate talkgroup for water supply units makes sense.
When you have a major storm with wires down all over the area (admittedly not often), putting the reports of wires down and pole numbers on a separate talkgroup from the fires caused by lightning strikes can be an efficient way to operate.
Haz-mat units usually need a separate talkgroup. Bomb techs need a separate TG.
You can't really appreciate the advantages of a trunked system until you've experienced it for awhile.

[werinshades]

Originally Posted by redburgundy

But listening to Radioman911's audio recording from the 4-11 yesterday, you can hear that the command van operator was unable to communicate with the incident commander on several occasions.

We're still having "growing pains" and most errors you might here are user errors. Unfamiliar with the radios is the biggest hurdle yet to overcome. I know, I work with them.

[redburgundy]

Originally Posted by werinshades

We're still having "growing pains" and most errors you might here are user errors. Unfamiliar with the radios is the biggest hurdle yet to overcome. I know, I work with them.

What was the reason for keeping analog for fireground/operations channels but shifting to digital for dispatch?

[werinshades]

Originally Posted by redburgundy

What was the reason for keeping analog for fireground/operations channels but shifting to digital for dispatch?

Don't know...not a decision-maker, just a worker bee.

[oemctx4]

Originally Posted by redburgundy

What was the reason for keeping analog for fireground/operations channels but shifting to digital for dispatch?

Digital doesn't work with air masks and chainsaws running. There is no need to use digital for simplex operations

[RoninJoliet]

Looks like "digital" is working for FGND for "Joliet City" and now "ENC" on top of that??....During the last two house fires heard nothing on FG-RED etc and nothing on there old analog trunk system which is still active with just some PW's....

[oemctx4]

Originally Posted by RoninJoliet

Looks like "digital" is working for FGND for "Joliet City" and now "ENC" on top of that??....During the last two house fires heard nothing on FG-RED etc and nothing on there old analog trunk system which is still active with just some PW's....

Digital Fireground Radios Undergo Second Round of Tests | FIRE CHIEF | Communications content from Fire Chief
Ron I guess testing is going on still going on I don't really follow fire life safety. That is what they decided to do.

[FFPM571]

I will take analog simplex any day over P25, repeater or trunked for fireground. There has been too many documented instances of poor signals or missed calls in an emergency situation. Even with the best repeater coverage transmissions can be missed. Simple radio to radio commuications is what has been found best for fireground traffic

.Despite Digital Advances, Analog Still Reigns on Fireground | FIRE CHIEF | Communications content from Fire Chief

[garys]

Somewhere along the line the NFPA recommended against trunked systems, digital voice, and even repeated fireground channels. I don't have the document, but I believe some of that was related to a coupe of incidents in NYC where FFs couldn't talk out on repeated UHF fireground channels. Maybe someone with a better recollection will chime in.

If you search out "fireground radio communications firefighter safety", you'll find a lot of information on fire ground communications and firefighter safety.

"Fire departments around the country have reported difficulties with digital radios, and studies performed
by National Institutes of Standards and Testing (NIST), the International Association of Fire Chiefs (IAFC),
and portable radio manufacturers have supported the findings from the field users. Based on the experiences
of fire departments using digital radios and the studies in response to these problems, the International
Association of Fire Fighters (IAFF) has taken a position that does not recommend P25 digital portable radios
for fire-fighting applications where the firefighter is using an SCBA.

These studies cite decreases in the ability of the firefighter’s voice to be translated into a digital signal by
the P25 radios. When fireground noise is introduced, the voice translation ability of the P25 radio provides
decreased to no intelligibility. These problems are worsened when the firefighter is speaking into the portable
radio through an SCBA facepiece, with or without a microphone inside the facepiece. Bone microphones or
throat microphones may minimize the interference caused by background noise but are impractical for most
firefighting portable radio uses. Speaker microphones are subject to the same problems that are found with
the microphone on the portable radio.

The configuration of the P25 vocoder is limited in its capability to translate the human voice in the presence of
common fireground noise or through a facepiece. This can pose a safety hazard for fireground operations. To
maintain safety, fire departments should consider using portable radios that incorporate analog modulation
for operations where the firefighter is using an SCBA.

Radios using the P25 digital technology have performed well for other fire service functions, such as on
emergency medical incidents, support functions on the fireground where an SCBA is not required, and
law enforcement operations. The difficulties presented by the inability of P25 radios to produce intelligible
voice messages in the presence of fireground noise is a significant safety concern and should be considered
seriously by public safety radio system designers and users."

You can read the entire document here.

[redburgundy]

Released: 02/11/2013. WIRELESS TELECOMMUNICATIONS BUREAU AND PUBLIC SAFETY AND HOMELAND SECURITY BUREAU SEEK COMMENT ON OPTIONS FOR 470-512 MHZ (T-BAND) SPECTRUM. (DA No. 13-187). (Dkt No 13-42 ). Comments Due: 05/13/2013. Reply Comments Due: 06/11/2013. PSHSB WTB http://hraunfoss.fcc.gov/edocs_publi...A-13-187A1.doc
http://hraunfoss.fcc.gov/edocs_publi...A-13-187A1.pdf
http://hraunfoss.fcc.gov/edocs_publi...A-13-187A1.txt