Ham radio and trunking

[n9upc]

Does anyone know if an amateur radio trunked system has ever been put on the air and if so what band, format, location, is it still running???

I was talking with some other hams who are also in PS and do communications for a living and we thinking a trunked radio amateur system could be of great usage.

Certain talkgroups can be assigned for certain purposes: one for weather emergency/spotting, one for nets, one for special events, one for echolink, etc...

In addition if you have it on a really good spot/location now it is no longer restricted to just one coversation on that tower. If you could get 3 or 5 repeaters pair you could have 3 to 5 off one lcoation on one band at the same time almost endless possibilities.

We thought that the best and simplest would be LTR or SmarTrunk as it seems like a majority of comercial rigs can do LTR or add-on a module for LTR or SmarTrunk.

Anyone heard of such a thing??

 

[NeFire242]

Well for an LTR all the repeaters much like a SmartZone would need to be located at the same tower site and you would need the use of a combiner to a single antenna, etc.

I'd like to see something like that implemented, and use 900MHz to link several tower sites and simulcast them with GPS clocks, etc.

I think it'd be nice to have one HT, and have a talk-group assigned to different repeaters on different bands, modes, etc. All with one radio, you could have a tieline to say DLink, one to a UHF repeater, one to Echolink, and so on.

This way end users would just have to worry about one HT, one format, and not have to worry about having a DStar or P25 radio, and yet another radio for this, and one for that.

Plus you can turn several of the "channels" on the LTR to go conventional with a DPL, etc, so that someone without an LTR radio can still communicate with others, etc. Lots of stuff you can do.

 

[N4DES]

Can you do it, I'm sure you could. But there is one hurdle that must be clarified by the FCC and that is the ID requirement on all of the frequencies that an individual utilized during the course of their transmissions. With the way the rules are currently written, if they don't ID on all of them then they technicially have violated the rules.

One other issue is the systems ability to ID on the control channel when that system has one. I do not think there is a way for any of these systems to do that without interrupting the datastream thus telling the end user that the CC is gone.

This topic has been brought up in may other forums and no one has ever identified any amateur trunking systems, although I have been playing with conventional talk-groups on my Amateur P25 repeater with great success.

 

[N8RUS]

Amateur radio is a hobby, not a business. There are no trunked systems. It would be cost prohibitive and serve no purpose at all. As far as EmComm-the purpose of AR is ........keep it simple. N8RUS

 

[EC-7]

It would be nice, but it would never happen, at least not till all the old farts either die, or accept that technology changes fast and the HAM hobby needs to also, or its going to die.

Repeater Freq coordinators in most states have set the pairs and freqs and WILL NOT make any changes to them for any reason. They wont accept new repeaters going up, ad they protect the non-used or "paper" non existent repeaters. For a trunking system you would need at least 3 freqs, and getting 1 is hard enough.

Also a lot of hams are so slow to want to upgrade their 1980's VHF radio to something that even has basic PL Encode and Decode, that going with something that requires more programming would be like pulling their teeth or dentures.

I give great applause to some of the groups in Texas and other areas that ar going with P25, DSTAR, Internet gateways or other new modes, as they are the only trend setters. There are too many other people that hold this hobby back and they are the ones that are killing it slowly.

 

[Caesar]

It would be nice, but it would never happen, at least not till all the old farts either die, or accept that technology changes fast and the HAM hobby needs to also, or its going to die.

Repeater Freq coordinators in most states have set the pairs and freqs and WILL NOT make any changes to them for any reason. They wont accept new repeaters going up, ad they protect the non-used or "paper" non existent repeaters. For a trunking system you would need at least 3 freqs, and getting 1 is hard enough.

Also a lot of hams are so slow to want to upgrade their 1980's VHF radio to something that even has basic PL Encode and Decode, that going with something that requires more programming would be like pulling their teeth or dentures.

I give great applause to some of the groups in Texas and other areas that ar going with P25, DSTAR, Internet gateways or other new modes, as they are the only trend setters. There are too many other people that hold this hobby back and they are the ones that are killing it slowly.

South Carolina D-Star SCDSTAR.com

we are trying to catch up with Texas and other states as quickly as we can. We see D-Star clearing taking a lead over P25 in the HAM world that isn't going to change anytime soon. D-Star!

 

[w8jjr]

trunking is not permitted on ham band per fcc

 

[burner50]

Is there seriously that much traffic on your local repeater system(s)?


Or do you want it just to have it???

As said before, repeater pairs are hard enough to come by... Tying up several sets just for you to say you have a trunked amateur system is kind of a ludicrous idea... not to mention its rather "clique-ish" due to the type of equipment / programming required.

 

[natrixgli]

I don't know about the OP, but here in my city, we have about 25 open FM repeaters that sit idle over 90% of the time. It's not like there's a shortage of available 2M/440 repeaters to use. From what I understand this isn't just unique to Milwaukee either.

-n8

 

[zz0468]

trunking is not permitted on ham band per fcc

Could you quote the specific source for this? It seems that I read somewhere that someone was doing it. I'm not sure I understand what the objection would be, at least on a regulatory basis. The little issue of how to ID all the channels is trivial. I would like to think that if anyone was to actually try this, they would take the time to think through the various hurdles, and just deal with them.

 

[zz0468]

It would be nice, but it would never happen, at least not till all the old farts either die, or accept that technology changes fast and the HAM hobby needs to also, or its going to die.

Clearly, you're hanging with the wrong crowd.

I see groups out west that, although heavily populated by "old farts", are as close to cutting edge as it's possible to be on an amateur budget. Turn off your two meter radio, and find the guys that are running microwaves, or linking systems, or running digital modes. They're out there.

As to the whole idea of trunking, if organized right, it could be a viable concept. I don't see it happening on any band other than 900, particularly since 900 trunked radios are CHEAP and widely available. So are frequencies, in many areas. As to prohibitive cost, that would depend on the size of the group and their dedication to making it happen. My ham radio budget is in the thousands of dollars per year, most of which is spent on operating activities and maintaining systems. I know dozens, no, maybe a hundred or more hams willing to spend as much or more. Pioneering advanced concepts is not a game for the stingy...

 

[newsphotog]

I don't know about the OP, but here in my city, we have about 25 open FM repeaters that sit idle over 90% of the time. It's not like there's a shortage of available 2M/440 repeaters to use. From what I understand this isn't just unique to Milwaukee either.

-n8

Yep, it's like that all over. I read that the folks who coordinate Kansas City metro repeaters only have one frequency pair left. I'll bet AT LEAST half of the currently "occupied" frequency pairs sit idle and the only thing they broadcast is their CW ID.

Though I would have to imagine there'd be a ton of frequencies available in the 900MHz amateur band because it's so under-utilized right now.

South Carolina D-Star SCDSTAR.com

we are trying to catch up with Texas and other states as quickly as we can. We see D-Star clearing taking a lead over P25 in the HAM world that isn't going to change anytime soon. D-Star!

I do agree with you. D-STAR will not slow down for a very, very long time and I think part of D-STAR's success over P25 is because it's actually designed for amateur radio use and the cost of D-STAR equipment is miniscule compared to P25. Not to mention the further modifications and programming. Though some will dispute this, but whatever. To each his own.

VIVA LA D-STAR!

 

[n9upc]

Interesting points thrown out!

First, if a system like this was to ever go on-line UHF or 900MHz would be the best bet for the task at hand. Many surplus radios in LTR format are out there and able to be picked up on a dime a dozen.

Second, as for ID'ing no big deal. Install a CW ID'er board in each Tx radio and then it is covered.

Third, as for the FCC and no trunking rule in the ham bands I have never heard of that and I will have to do some checking into that.

Fourth, yes a lot of repeaters are sitting and just ID'ing, mainly because of other forms of communication. However, some people still like to play and do talk on repeaters. I myself only chat on a few select repeaters because they offer GREAT coverage and we all know a lot of people on the repeater. Yet, this still does not stop me from making sure I have other repeaters in the area or places I travel in the radio memory.


This was just some talk we had going around a table one morning while having coffee. We can see the advantages: mutliple channels at one good location, thus multiple conversations that can take place, different talkgroups for different purposes (i.e. weather spotting, echolink, etc...)

We can also disadvantages: amateur radio ops not wanting to buy ex-commercial equipment, controller equipment, new technology = scary for some people.


As stated I thought someone did have a trunked amateur system at one time up and running and I thought it was 900 MHZ and maybe somewhere out west in CA maybe.

Who knows but hey to each their own!

 

[n5ims]

Second, as for ID'ing no big deal. Install a CW ID'er board in each Tx radio and then it is covered.

I believe that the ID issue isn't for the repeater, but for the op. With a trunking system, the op may bounce around on several frequencies and may not give a proper ID on each frequency they had used. With commercial systems, everyone operates under the same ID so it's OK to only have the repeater give the ID. With amateur operation, not only the repeater must ID, but every operator must ID as well.

For example, a 4 frequency system is in use. The initial call is made on talkgroup A, which is initially assigned to frequency 1. During this initial call, the ops give their call sign so all is OK at this point. There's a brief pause in the conversation and the trunking system switches that talkgroup to frequency 3, they talk for a bit without any calls given and pause again. The system now switches them to frequency 2 where they again ID. Their conversation wan't 100% legal due to no IDs being given while talking on frequency 3.

From part 97.119 "Each amateur station, except a space station or telecommand station, must transmit its assigned call sign on its transmitting channel at the end of each communication, and at least every ten minutes during a communication, for the purpose of clearly making the source of the transmissions from the station known to those receiving the transmissions. No station may transmit unidentified communications or signals, or transmit as the station call sign, any call sign not authorized to the station."

While it may be argued that using the trunking system, the "communication" was continuous and IDs were given as instructed, it could easily be argued by those using non-trunked radios that no IDs were given. Almost like having a conversation on one frequency, but switching to another frequency to ID so those on the first frequency won't know who you were.

 

[N4DES]

ding...ding...ding... We have a winner!

I believe that the ID issue isn't for the repeater, but for the op. With a trunking system, the op may bounce around on several frequencies and may not give a proper ID on each frequency they had used. With commercial systems, everyone operates under the same ID so it's OK to only have the repeater give the ID. With amateur operation, not only the repeater must ID, but every operator must ID as well.

For example, a 4 frequency system is in use. The initial call is made on talkgroup A, which is initially assigned to frequency 1. During this initial call, the ops give their call sign so all is OK at this point. There's a brief pause in the conversation and the trunking system switches that talkgroup to frequency 3, they talk for a bit without any calls given and pause again. The system now switches them to frequency 2 where they again ID. Their conversation wan't 100% legal due to no IDs being given while talking on frequency 3.

From part 97.119 "Each amateur station, except a space station or telecommand station, must transmit its assigned call sign on its transmitting channel at the end of each communication, and at least every ten minutes during a communication, for the purpose of clearly making the source of the transmissions from the station known to those receiving the transmissions. No station may transmit unidentified communications or signals, or transmit as the station call sign, any call sign not authorized to the station."

While it may be argued that using the trunking system, the "communication" was continuous and IDs were given as instructed, it could easily be argued by those using non-trunked radios that no IDs were given. Almost like having a conversation on one frequency, but switching to another frequency to ID so those on the first frequency won't know who you were.

 

[N4DES]

the cost of D-STAR equipment is miniscule compared to P25. Not to mention the further modifications and programming. Though some will dispute this, but whatever. To each his own.

VIVA LA D-STAR!

Try again...locals around here have purchased APCO25 capable equiment for as low as $150.00. I'm not disputing...it is factual. Try to do that with D*.

Both technologies have their positives and negatives. One thing for sure, looking at the activity levels of D* repeaters linked to the web is not very impressive. The local one here has maybe a documented log-on once every 2 or 3 days and its usually the same guy. The stufff may be out there, but no one is using it. On the other hand my APCO25 repeater has daily digital QSO's throughout the day with at least 1/2 dozen users at a time.

Down here, APCO25 rules.

 

[James_Bond_007]

I have to say LTR on 900 Mhz linked via 1200 mhz or 10 ghz and tied to GPS.

for a place like NJ here a state-wide linked LTR repeater on 900 mhz properly engineered would work wonders.

it would require a lot of stuff to fall into place and it would require the help of the state OEM along with every ham club to put aside their differences and band together to make it happen and to maintain it.

it's not out of the realm of possibility. especially in NJ where the small size of the state and terrain and the dense population would make such a system viable.

but as stated would require lots of organization and cooperation.

 

[zz0468]

ding...ding...ding... We have a winner!

Do we? So, ok... sure. User ID on the different frequencies is an issue. How hard would it be to get an ID sent on every PTT? Hey... the commercial world does it all the time.

I would submit that if any group was going to actually try this, they would probably quickly find that commercial off-the-shelf trunked systems are not suitable for amateur use. So, it would likely have to be heavily modified for amateur use. Too complicated you say? Nope. There's some pretty damned sharp people in the hobby. Look at what TAPR did with AX.25 - modifying an existing protocol to answer amateur needs. Look at the work done at Batlabs, making Motorola software and hardware speak amateur frequencies. Look at how the microwavers modify commercial wideband gear and make SSB radios out of it - sometimes WAY out of it's intended frequency range. "Amateur" just means they're not doing it for money. Not everyone in the hobby is a hack who can't solder a PL259.

Most, if not all, of the technical or regulatory issues presented here could be overcome by some effort. It would be an over simplification to state that an existing system and protocol could be immediately pressed into service. It's possible that an STA could be required for development. The FCC is VERY receptive to issuing STA's to amateur groups wanting to try new ideas. I know people smart enough to pick apart the firmware of a trunking controller and get it to do something different. I fully expect someone to come up with a 900 MHz amateur trunked system someday.

 

[N4DES]

Do we? So, ok... sure. User ID on the different frequencies is an issue. How hard would it be to get an ID sent on every PTT? Hey... the commercial world does it all the time.

Sure it can be done now with Soft ID in APCO25, but would it be worth the expense? I think not and can't think of any other trunking protocol that has that feature. Also any type of subaudio or data transmision for ID purposes must be a recognized standard per Part 97.

 

[jparks29]

Try again...locals around here have purchased APCO25 capable equiment for as low as $150.00.

I was one of them

Guy on ebay was selling an Astro Saber 2R, didn't know what it was, nicely flashed, with 7/7 host/dsp, I got it for about 125$... I had to dump another 50$ for a ruggedized battery, but it was oh so worth it.