• To anyone looking to acquire commercial radio programming software:

    Please do not make requests for copies of radio programming software which is sold (or was sold) by the manufacturer for any monetary value. All requests will be deleted and a forum infraction issued. Making a request such as this is attempting to engage in software piracy and this forum cannot be involved or associated with this activity. The same goes for any private transaction via Private Message. Even if you attempt to engage in this activity in PM's we will still enforce the forum rules. Your PM's are not private and the administration has the right to read them if there's a hint to criminal activity.

    If you are having trouble legally obtaining software please state so. We do not want any hurt feelings when your vague post is mistaken for a free request. It is YOUR responsibility to properly word your request.

    To obtain Motorola software see the Sticky in the Motorola forum.

    The various other vendors often permit their dealers to sell the software online (i.e., Kenwood). Please use Google or some other search engine to find a dealer that sells the software. Typically each series or individual radio requires its own software package. Often the Kenwood software is less than $100 so don't be a cheapskate; just purchase it.

    For M/A Com/Harris/GE, etc: there are two software packages that program all current and past radios. One package is for conventional programming and the other for trunked programming. The trunked package is in upwards of $2,500. The conventional package is more reasonable though is still several hundred dollars. The benefit is you do not need multiple versions for each radio (unlike Motorola).

    This is a large and very visible forum. We cannot jeopardize the ability to provide the RadioReference services by allowing this activity to occur. Please respect this.

P25 Trunking & Radio to Radio Simultaneously?

Status
Not open for further replies.

Longjohns

Newbie
Joined
Dec 4, 2016
Messages
1
Location
USA
Something I have been pondering for some time now is the possibility of P25 radio to radio communications while simultaneously transmitting to a tower for trunking purposes. In the event you hit a dead zone, your transmissions will still be heard by those on scene. While I am not a radio or IT professional, I consider myself to know enough to f*** some s*** up! LOL...

With experience with end-user radios in the fire, EMS, police, and emergency dispatch services I have a hard time with P25 trunking systems (or at least the way they've been set up). Why are we using a system in emergency services that requires a radio transmission to hit a tower? No, this is no way just another thread about how folks can't move forward with technology and want to keep their low band radios. My area has had a P25 trunking system for nearly a decade and I know that P25 is here to stay. It's about DEAD ZONES...

THE ISSUE:
When a LEO is operating inside of a large building during an active shooter incident or firemen are working at the scene of a basement fire, the loss of communications between personnel on scene due to a radio transmission not being able to reach a tower is not acceptable in these high risk scenarios. The sad part is that an FRS radio in these scenarios would likely allow LEO's and firemen to still communicate between themselves where P25 trunking can't.

SOLUTION (From a non-first responder perspective)
Change your radio to a digital conventional channel. Yes in the heat of that worst life or death moment in your LEO/fire/EMS career, you should stop to change a channel that is on another bank, on a radio that is buried in your PPE! Did you even know you were in an area that didn't have P25 trunking coverage?

Oh wait, you're now dead...


PRACTICAL SOLUTION
With a life/death situation, I don't give a flying f*** if the rest of the county or the dispatch center can hear me. After all, they are not going to be the ones to risk their life to save me as my on scene partners will do that. Is there a solution for this? Something that is automated and proactive that does not require you and everyone else on the incident to manually switch to a conventional channel?
 

RKG

Member
Joined
May 23, 2005
Messages
1,087
There is no way for a subscriber radio transmitting on a trunked system voice channel to simultaneously transmit on some other conventional channel.

"Failsoft" will cause subscribers to switch from listening to the control channel (in Rx) and transmitting an ISW channel grant request (in Tx) if the trunked system fails. But if only one guy on the scene has lost contact with the trunked system, Failsoft won't switch other people's radios and no one will hear him.

This is why use of a trunked talkgroup for "fireground" or "incident ground" tactical communications is problematic. And the reason why, on the fire side, use of a trunked talkgroup for fireground communciations is "outlawed" by NFPA 1221. (NFPA standards are not binding; hence the quotes on "outlawed.")
 

12dbsinad

Member
Joined
Mar 15, 2010
Messages
1,083
Something I have been pondering for some time now is the possibility of P25 radio to radio communications while simultaneously transmitting to a tower for trunking purposes. In the event you hit a dead zone, your transmissions will still be heard by those on scene. While I am not a radio or IT professional, I consider myself to know enough to f*** some s*** up! LOL...
No, not gonna happen.

With experience with end-user radios in the fire, EMS, police, and emergency dispatch services I have a hard time with P25 trunking systems (or at least the way they've been set up). Why are we using a system in emergency services that requires a radio transmission to hit a tower? No, this is no way just another thread about how folks can't move forward with technology and want to keep their low band radios. My area has had a P25 trunking system for nearly a decade and I know that P25 is here to stay. It's about DEAD ZONES...
Why are we using services that hit a tower? Because what else are we going to hit, the moon? You will ALWAYS have a dead zone, there is no such thing and probably never will be 100 percent coverage everywhere you will ever go with any system. That is just reality.

THE ISSUE:
When a LEO is operating inside of a large building during an active shooter incident or firemen are working at the scene of a basement fire, the loss of communications between personnel on scene due to a radio transmission not being able to reach a tower is not acceptable in these high risk scenarios. The sad part is that an FRS radio in these scenarios would likely allow LEO's and firemen to still communicate between themselves where P25 trunking can't.
Correct. This is why in these types of scenarios utilization of simplex communications is vital. That's why it will never go away. Look up the issues with Firstnet in regards to simplex communications.

SOLUTION (From a non-first responder perspective)
Change your radio to a digital conventional channel. Yes in the heat of that worst life or death moment in your LEO/fire/EMS career, you should stop to change a channel that is on another bank, on a radio that is buried in your PPE! Did you even know you were in an area that didn't have P25 trunking coverage?
This shouldn't be a big deal. And, in most cases, this should be done well before entering the hot zone. Trunking systems and in building coverage/ reliability have always been an issue. Just look at the NFPA recommendations, this doesn't include trunking systems for fire ground operations.




PRACTICAL SOLUTION
With a life/death situation, I don't give a flying f*** if the rest of the county or the dispatch center can hear me. After all, they are not going to be the ones to risk their life to save me as my on scene partners will do that. Is there a solution for this? Something that is automated and proactive that does not require you and everyone else on the incident to manually switch to a conventional channel?
This should be done regardless. In my area, we switch to fire ground simplex analog before even exiting the truck. Command stays on dispatch and fire ground. It's just the most reliable method of communications there is on the fire ground. With the understanding that nothing is perfect.
 
Last edited:

surfacemount

Member
Joined
Jul 5, 2011
Messages
116
Location
Knox / Roane / Loudon counties, Tennessee
You need to look into dynamic steering. This could even be tied to a soft button on the radio.

I understand your frustration. One of the things we tried was putting a conventional personality at position 16 on the portable, you get into something, just twist til it stops and truck on. Didn't work well.

There's really no good answer, and moving public safety to the 700Mhz band only exacerbated the issue.
 

RKG

Member
Joined
May 23, 2005
Messages
1,087
"There's really no good answer . . . ."

Actually, I think there is a good answer, and it starts by taking a step back from our fascination with technological marvels and remembering that our mission as radio techs is to fashion a tool that works for the job the guys have to do.

Repeaters are designed to extend the range over which two field units can talk directly to one another, further than what can be done using simplex channels. This is basically a police function, since in the fire service 99% of all radio traffic is either between Fire Alarm and apparatus or between fire fighters in close proximity to one another on the fireground; a repeater does nothing to extend workable range for either.

Now, repeaters are neat devices, but they have their limitations. On the repeater channel, users are transitting and receiving on different frequencies, which means that they can only talk to one another if the repeater is working and they can hit it. As a result, adding a repeater to the mix injects a whole host of additional potentials for failure. It may make sense to accept this reduced reliability if we need a repeater's added user-to-user range; it does not make sense if there is no such need.

From a technical perspective, trunked systems are even more exciting to play with and can extend range expoentially further than repeaters. I can, for instance, take my 3-watt portable in Winthrop and talk to a trooper (or another tech) who is in the boondocks over 120 miles away! Fascinating, but how often is that range required for a real world operation? And if a trunked system expands range exponentially, it also expands failure modes in like proportion. Here, not only are the users who need to talk to one another transmitting and receiving on different frequencies, but there is no way to know what frequency your potential rescuer is listening to (in order to use "direct"), and, if his radio has gone back to the control channel, your rescuer isn't listening to any voice channel.

So I submit that the problem the OP raises is not a failure of technology, but rather a failure of those who make the decisions (and, I'm convinced also the failure of those who give technical advice and guidance to the decision makers). What happens is we take the newest and greatest technical toy, declare it to be the tool for use on all occasions and in all situations, and make no attempt to fit the tool to the job.

Now, I must point out that there are exceptions. Boston Fire uses repeated channels both for dispatch and on the fireground, and it does not give firefighters a "direct" option in their radios. But on any fire of significance, Boston FD dispatches to the scene a Tactical Command Unit manned by a Fire Alarm Operator who listens to eight frequencies: the four repeated outputs and the four repeated inputs. His job to is be sure that no transmission goes unheard and unanswered.

Across the river, Cambridge FD uses a trunked system for dispatch and administrative functions, such as FPU and FIU. But on the fireground, firefighters switch to conventional channels; these are repeated, but the firefighters have access to "direct." Cambridge goes further; it repeats the conventional audio to trunked talkgroups so that responding apparatus can monitor what is going on on the fireground while they are enroute, and thus be better equipped to deal with what they face when they get there as well as to receive orders before arrival.

So, Virginia, there are good answers. But they will be found only where the people who make decisions (and those who give them technical advice) are smart enough and dedicated enough to do the work to make the tool fit the job.
 
Status
Not open for further replies.
Top