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  #41 (permalink)  
Old 07-07-2012, 7:43 PM
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Cobb County, GA uses simplex channel because on the DTRS when you are wearing BA you can't understand a single word anyone is saying.
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  #42 (permalink)  
Old 07-07-2012, 10:23 PM
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Quote:
Originally Posted by phillydjdan View Post
In the Philadelphia area:

Montgomery County PA uses an 800 MHz digital trunked system, and they do one of two things for fireground operations. Either they use a set of analog talkgroups on the system (called "event" channels), or they can use 1 of 6 simplex analog frequencies. I cannot confirm if dispatchers have access or monitor them or not.
Not sure if this is still of any use, but I can confirm that Montgomery County does NOT have the capability to monitor the analog fireground frequencies. This also means the emergency button on radios tuned to these frequencies will not trip an alert in the dispatch center. Event channels are monitored and the county will communicate on them as necessary, such as for the aforementioned emergency identifier alerting.

Incident commanders have the choice of choosing to operate on one or the other; Event channels get assigned by the county dispatcher, while normally Fireground channels are selected by what region the incident is taking place in (Region 5 companies normally operate on Fireground 5 unless circumstances dictate otherwise, etc). The reasons for operating on one or the other are company preference--one oft stated reason to use Fireground channels is that it keeps all communication local, in that operations aren't repeated across the system, which allows for command to have tighter control on traffic to and from the dispatch center.
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Old 07-08-2012, 1:23 PM
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Default More importantly, WHY should they?

A little background first. Please bear with me during this explanation.


Command Structure Theory: Per NIMS/ICS, all command structures are triangular. At the top apex of the triangle is the boss. The boss can be anyone from a fire company officer to the President. Along the bottom (not just at the corners) are his subordinates; department heads, staff, employees, firefighters, etc. In the perfect world, there are no more than seven folks on the bottom row, with three to five being optimal. (AKA “Span of Control”)

Depending on the size or scope of the operation or organization, the folks on the bottom of a triangle may each have their own triangle with themselves at the top. For instance, if the top-top dog is the Mayor, his subordinates could be the Fire Chief, Police Chief, Public Works, Accounting, etc., and each department has its unique own triangular structure.

In this case, the Fire Chief is under the Mayor, but sits at the top of his own triangle. Depending on the size of his department, his bottom row could be populated with individual firefighters, or more triangles comprised of battalions, companies, or operational divisions.

Continue this on down until the bottom row is comprised of individual firefighters wearing SCBA’s and working at the wet end of the hose.

Span of Control: If you are on the bottom of the triangle, finding your boss should be easy: look up. It doesn’t make any difference how many triangles are in the organization. When you look up, there is the man, and only one of them. If you are at the top, look down: those are the folks whose lives you are responsible for.

Is there anyone out there who can really supervise thirty subordinates, all performing different tasks? Nope. That’s why Span of Control is limited to realistic quantities. And the more life-threatening their duties, the fewer folks you should have directly under you. If one of “your” people yells MAYDAY, you better be paying attention and not negotiating with the grocer for sandwiches.

Chain of Command: Two-way communication within each triangle is critical. Firefighters need to communicate “sideways” with each other, and “Up” to their boss. Their boss needs to have situational awareness of what’s going on both under and around him. But, an individual on the bottom-most rung doesn’t need to talk directly to the Mayor, or to the chief of a triangle two units over. He talks ‘Up” to his boss and his boss passes the communication on- that’s HIS job. Equally important, an individual firefighter doesn’t need to hear distracting unrelated chatter from other triangles.

Conversely, the Mayor (or Dispatcher, or battalion Chief) better not call two or three triangles down to some poor schmuck holding the hose telling him to shoot his water into a particular window. In the perfect world, the request travels down the chain of command. That hose stream may be going in a particular direction for a reason the Mayor/Dispatcher/Etc. in unaware of, like cooling an LP tank to keep it from exploding.

Accountability: No matter where you are in this triangle of triangles, each person has one and only one boss. And each boss has a limited number of staff for whom he is accountable for, and whose life and safety are his foremost priority. White Helmets come with a radio for each hand: one “Up”, and one “Down”. If in doubt, pay attention to the “Down” radio.


NOW that that is out of the way, how does this relate to the topic at hand?


Each triangle has its own unique communications requirements and needs its own network. At the top, the Mayor communicates within his triangle via telephone and email. If there’s a delay of a minute or so, nobody will die.

The Fire Chief (through his Dispatchers) notifies companies of fire calls via a paging system. A Company Officer communicates with Dispatch, his boss, and other responding companies via a repeated or trunked radio system. Communication should flow reliably and seamlessly over a wide area. Timeliness is important, but not super-critical. Repeater or trunking system failure is an inconvenience to be planned for. Again, the likelihood of death or injury caused by a thirty-second delay is slim.

Here’s the rub: Let’s say you are a firefighter wearing seventy pounds of gear, crawling into a three-hundred degree room with a hose. Your immediate, reliable, real-time communications ARE critical to your life and safety.

First question: If you are the above firefighter and have a “situation” like no air, no water or a brother ‘down’, would you want to A) rely on a high-tech digital trunked repeater system with the closest tower a couple miles away to fold, spindle and mutilate your MAYDAY before delivering it to you boss a couple hundred feet away, or B) rely on a simple, stupid low-tech analog radio that can be heard directly by your boss a couple hundred feet away?

Second question, same situation as above: Would you A) want your MAYDAY to be heard immediately, or B) want to wait on some distant voice to shut up (or a “ready to talk” chirp) before you can yell MAYDAY?

Third question: You are the on-scene Operations Chief with your interior attack team inside a burning building. Would you A) want to hear everything from them immediately, without interference, or B) want to hear distant or unrelated traffic while your interior attack crew was calling MAYDAY?

Final question: If you are a dispatcher miles away from the fire, can’t hear on-scene portable traffic, and have a radio that can walk all over portable radios that are on-scene, would you want to A) never transmit for fear of interfering with life and safety-critical traffic, or B) call the Incident Commander to chat about what’s going on and give him a traffic and weather report?

Can Dispatchers (and the Radio Reference Community) hear all on-scene tactical communications if tactical is only performed over simplex unrepeated radios? No. Ask yourself if is this a legitimate need, or a nosey “want”.

Can a remote base station record all on-scene simplex tactical traffic? Not always, but this is easily accomplished with a radio and recorder in an on-scene vehicle. Both satisfy the need for reconstruction when things go south. A local recorder is cheaper, more accurate and doesn’t put lives at risk


Do all departments follow the above? Nope. Should they? Ask the families of the forty or fifty firefighters over the past ten years who did not come home at the end of their shift because their department’s policies didn’t follow the above.
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Last edited by jeatock; 07-08-2012 at 1:42 PM.. Reason: Can't speel...
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  #44 (permalink)  
Old 07-08-2012, 3:58 PM
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When training our fire guys, I strongly recommend they NEVER go interior on a talkgroup on a significant call, as you are literally rolling the dice with firefighter safety every single time.

They have analog and digital simplex options for fg use, but it is ultimately up to the IC.

Some depts. listen and choose not to roll the dice with their guys' safety. Others don't listen and go interior on talkgroups every single time, no matter how dangerous the call is.

Nothing else I can do but pray luck shines upon those that don't listen. At least I can sleep at night knowing I've done my best to warn them.
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Old 07-12-2012, 4:30 PM
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Philadelphia County, Pennsylvania (PA) Scanner Frequencies and Radio Frequency Reference

Philadelphia Pennsylvania FD has 3 simplex fireground channels

Seems that most comms are done on the TRS

Does anyone know what the encrypted Tac channels are used for? Mostly for Chief to Dispatcher reports?
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Old 07-13-2012, 5:04 AM
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Quote:
Let’s say you are a firefighter wearing seventy pounds of gear, crawling into a three-hundred degree room with a hose. Your immediate, reliable, real-time communications ARE critical to your life and safety.

First question: If you are the above firefighter and have a “situation” like no air, no water or a brother ‘down’, would you want to A) rely on a high-tech digital trunked repeater system with the closest tower a couple miles away to fold, spindle and mutilate your MAYDAY before delivering it to you boss a couple hundred feet away, or B) rely on a simple, stupid low-tech analog radio that can be heard directly by your boss a couple hundred feet away?
This could be "What if'd" to death, but I agree, for the most part.

My department had a recent call where this could have been an issue. (We are a combination department, which runs two single staff stations plus on-call firefighters.) During a fire alarm call, to a commercial building, the first arriving officer was unable to talk outside the building, to the next arriving trucks. Luckily, nothing time-critical was lost in the lack of communications.

Quote:
Second question, same situation as above: Would you A) want your MAYDAY to be heard immediately, or B) want to wait on some distant voice to shut up (or a “ready to talk” chirp) before you can yell MAYDAY?
To be fair: many (most?) systems with emergency buttons give the presser preemption over current transmiters. Yes, you still have to wait for the chirp, but that is less than a second. (The delay is less, when your talkgroup has a dedicated repeater.)

Quote:
Third question: You are the on-scene Operations Chief with your interior attack team inside a burning building. Would you A) want to hear everything from them immediately, without interference, or B) want to hear distant or unrelated traffic while your interior attack crew was calling MAYDAY?
You are more likely to hear interfering radio traffic on a discrete radio frequency, than on a fireground talkgroup. You could pick up traffic from any number of other users, especially during "skip traffic" times.

Quote:
Can a remote base station record all on-scene simplex tactical traffic? Not always, but this is easily accomplished with a radio and recorder in an on-scene vehicle.
There are added expenses to local recordings, plus you have to maintain a library, for FOIA requests. There are other logisitical concerns, too:
1) Who retrieves the recordings?
2) How often are recordings retrieved?
3) How are recordings stored?
4) Where are recordings stored?
5) How long are recordings stored?

Obviously, these problems grow with the size of the department. Plus, if your dispatch is an outside agency, whose recordings are the official source?
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  #47 (permalink)  
Old 07-13-2012, 5:53 PM
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Miami-Dade County, Florida (FL) Scanner Frequencies and Radio Frequency Reference

If Miami FD has a simplex channel, it is not listed.

The Miami PD do have 1 simplex channel listed.
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Old 07-13-2012, 6:01 PM
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Orange County, Florida (FL) Scanner Frequencies and Radio Frequency Reference

Apopka Florida Police and Fire both have conventional 800 Mhz repeaters for when the county digital TRS crashes and burns

If Orlando or other area FDs have simplex channels, they are not listed here in the database.
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Old 07-15-2012, 3:23 PM
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Quote:
Originally Posted by krokus View Post
This could be "What if'd" to death, but I agree, for the most part.


For every rule there is always an exception. The Coast Guard has the most sensible rule I've ever seen. In regard to navigation, you may break any other rule as long as you are successful in avoiding a collision or loss. The key word, however, is 'successful'.

My frame of reference is mostly volunteer or small mixed FD's. You would be shocked by the extreme lack of communications planning, ancient equipment and procedures, and total lack of training when it comes to radio. For many FF's, change is always bad; that channel/radio/procedure was good enough for Grand-dad when he was on the department so it's good enough for us.

I had one rural department spend four months discussing changing their fireground tactical frequency to a statewide standard to improve interoperability and avoid interferring traffic from a metro area fifty miles away. Thirty FF's argued amongst themselves at many meetings and took it to a vote of the entire department- they voted that their ears could only understand voices transmitted on Grand-dad's 154.250 radio frequency and that voices transmitted on 153.830 would be unintelligible. In another situation a volunteer fire chief told me that while he felt his troops were fully qualified to perform burning haz-mat operations along a busy Interstate highway, they needed to use one channel for everything at all times because changing channels on their radio was too difficult.


In most of the incidents I have looked at where communication failure was an issue, there are four basic causes:

1) Congestion or interference where everyone (including related paging for other departments/incidents) was on one channel, including off-scene same-system base stations walking on critical on-scene portable traffic. This also applies to simplex 'talkaround' operations on a repeater downlink frequency.

2) Harmful (but legal) interference coming from off-scene stations transmitting with different squelch codes. Few can seem to get their head around the concept that a receive squelch code combined with a low carrier squelch setting, while necessary to allow for optimal reception of desired weak signals and remove interfering signals, does not get rid of the interferer, only masks it. Change frequencies, not CTCSS or DCS.

3) Receiver de-sense caused by nearby transmitters on an unrelated channel, or on the uplink frequency of your selected repeater's channel pair. Either way any nearby transmitter on a different frequency (even if it is on the same 'channel') deafens other receivers in the area to the point they can't hear a repeater's base transmitter at a proportional distance. The desensatizing source could be one of your own on-scene, the local country music station, leaky cable TV coax, or the cement truck waiting in blocked traffic. Simplex operations even at two watts don't have this issue on the typical fireground.

Field test: On a boring sunny day, take three trucks ten miles from your repeater, park twenty feet apart with everyon'e radio set to the same repeater channel and try to talk to each other through the repeater. Have truck 'A' change to an unrelated channel and transmit while 'B' and 'C' try to talk through the repeater. Try the same with portables, only this time a mile from your repeater.

Chances are it won't fly, even though someone thirty miles away can hear all of you. Know what doesn't work before it hits the fan and train accordingly. (Trunking radios relying on data signaling, and all digital radios, even with 'error correction', are even more susceptible to this.)

4) Lack of training, or incompatible, poorly maintained or badly programmed equipment. Us firefighters like to train with all our fun toys once or thrice a year. Communications training? Nah, that's boring Geek stuff. Radio performance checks??? Why? It's worked OK for the past five years. Panic button? Probably half of the volunteer departments are lucky to have ANY radio for everyone on scene, much less a new fancy one with bells and whistles the department can't afford, much less operate.

Recordings (while important) are a matter of policy and budget, and politics. The solution is simple: do all you can afford, and enforce the right polices.

Overall, train on what works and what doesn't, learn from the mistakes and successes of others and be ready to go to 'Plan B' when (not if) 'Plan A' fails... like for any of the above, or the crash and burn (or partial failure) of an infrastructure system.


----------------------------------
PS, re. this discussion being off-topic: The original poster asked about simplex vs. repeated/trunked operations for life and safety critical fireground tactical communications. The MABAS/Illinois standard - used by many rural Illinois volunteer FD's - is for critical incident tactrical communications to take place on one of six standardized analog VHF simplex low power channels- no base transmitters allowed. Off-scene traffic, including Command and Control and paging, always take place elsewhere. I support this for the reasons previously stated, and offer my opinion based on the experience of others as to why this is sound policy.

Insofar as dispatch use of fireground tactical channels, rural Illinois might if the fire is in town. Further off it is a maybe.

I have two thoughts on that. Our county PSAP has two telecommunicators monitoring eight radio channels, plus regular telephone, plus 911, interchangeably. They can monitor some fireground channels, but there simply aren't enough ears. Its a matter of priority: listen to a scratchy firefighter voice coming through an SCBA to the pump operator, or take a 911 medical call, or monitor a law enforcement traffic stop where dispatch IS the safety oversight. Guess what channel gets turned down first.

Second, why would a dispatcher need to talk directly with an interior firefighter holding a hose? Dispatch has an overview, but no first hand knowledge of the exact situation and is not in a position to start a conversation. That communication would be better served by communicating with the incident commander outside, or even the pump operator. As far as monitoring for a MAYDAY or RIT call, someone outside on scene should have that safety oversight assignment, with backup by everyone else on scene.
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Last edited by jeatock; 07-15-2012 at 5:12 PM..
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Old 08-19-2012, 2:46 PM
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DC Fire & EMS Department report on vacant house fire that injured five firefighters. Read entire report. | STATter911.com

The report found here contains the SOPs for the Mobile Repeaters used by the Washington DC FD. In addition, the report contains information about the radio communications problems at this 1 fire.
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Old 05-09-2013, 8:03 PM
   
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What was the outcome here? I'm looking for similar information.
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Old 05-18-2013, 8:51 PM
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Morris County, NJ uses a 400 Mhz Trunk System for Response and have two analog simplex frequencies for FG, which are not monitored by the Dispatcher.

Last edited by EJM; 05-18-2013 at 8:55 PM..
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Old 05-28-2013, 8:34 AM
   
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I'm curious as to what the outcome was here. I'm needing similar info for our FD. We currently operate on digital, repeated channels for hazard zone ops. Looking for FD's that have digital systems but use the talkaround channels for fireground.
Thanks
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Old 05-28-2013, 10:43 AM
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London Fire Birgade (London, England) Digital (Airwave) TETRA for normal ops UHF analog for fireground.
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Old 05-28-2013, 3:04 PM
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Wirelessly posted (Mozilla/5.0 (X11; Linux i686; U; en-US) Gecko/20081217 Vision-Browser/8.1 301x200 LG VN530)

It would appear that many, but not all, FD's that use a trunked system, also have conventional simplex channels in the same or different band. You'd have to go through the thread, read and count each reply.
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Old 05-29-2013, 7:56 AM
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The short answer:

All of them.

There would be an extremely short list of trunk users that do not have simplex fireground channels (in band or out of band) available.
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Old 05-29-2013, 8:13 AM
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Our local City FD got on the state digital trunk system and now they think that somehow other radios don't or won't work. So, they still have some VHF but they won't touch them. Not sure their 700/800 radios even have any simplex capability, and if they did, no one would know how to use it.

The sad truth is $10M worth of radio gear does no one any good when they are not trained on it's use, or despite training play dumb and just plain won't use features offered.

A local industrial plant has VHF for the FD in their security base. The FD still has their VHF repeater and base on the air. Calls going out over the trunked system are simulcast over the VHF via the console. When the industrial plant does a radio test weekly, the fire dispatcher ignores them several times, then finally answers them and says "We are on the State system now, we can't talk to you". One day, I heard the plant say "But you can hear me there in dispatch now, right?" and the dispatcher said "Yes, but these radios don't work no more". The plant said "Ok, but as long as they are on the air there in dispatch I should be able to get you". To which the dispatcher said "Yes, but these radio don't work....call us on the new system" (Which they don't have at the plant - it's for public safety).

You can't fix stupid.
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