Trunked on Ham?

[Mars_P25]

Let's stick to the question. What are the technological and administrative hurdles that must be crossed to put a trunked system on the air in the amateur radio service? Is it possible? How would you go about it? If you aren't answering those questions, don't post. It's as simple as that.

It has already been done. It wasn't hard. Acquire repeaters. Flash with Linked Capacity Plus. Install microwave backbone (way easier than it sounds, and not expensive -- just time and a few headaches). Connect sites. A few remote sites connect via Internet, but they're not as reliable due to UDP/packet loss when people are watching porn and Netflix at peak hours.

In terms of a need, here goes: (point form)

- As stated multiple times, with timeslot-trunking, there's no timeslot-strapping, which ties up resources (voice channels, aka "rest channels" in Moto-speak) system-wide.

- With Linked Capacity Plus (and other trunking formats), talkgroups can be programmed into the controller with routing settings. That means we can have wide-area groups, or groups that bring up certain sites only. Or, just simple "local" talkgroups which only involve activity on the site they originate on.

- We can send out-of-band (not on active voice channel) data, such as Radio Check commands, Call Alert, individual or group text messaging or security packets, such as Radio Disable/Enable, if a radio goes missing.

- We can control who accesses the system via Restricted Access to System (RAS), which is essentially infrastructure protection. It keeps CCRs and improperly programmed radios off the network. It is not encryption. (But we run encryption anyway, because we can)

- Repeater health monitoring via admin software. We can check VSWR, voltages, power output, temperatures, power status (AC or battery backup), control channel status (revert one or many repeaters into analog service, if required for ARES whackers), etc. Admins get instant emails if a site sends out any error message. I don't know of any ham analog CSQ setups that do that.

- We get two talk-paths for each physical repeater at a given site, with a maximum of 16 timeslots per-site. Can't do that with DSTAR, Fusion or P25 (without a trunking controller, which also ties up an RF frequency as a dedicated control channel at each site).

- We have a log of every PTT access on our system. Useful for troubleshooting. We can disable/block Radio IDs if needed (stolen, someone drunk, etc.)

- A site goes down (on IP), and the rest of the network stays together. This includes the master site. In the analog world, if the hub site went down, your backbone would fail.

- Consistent audio quality across our entire network. No problems with distortion/poor levels. Anyone who wants to argue this obviously hasn't optimized their MOTOTRBO subscribers with the latest firmware/enhancements. I had a large role in that process, back in 2015.

- The ability to engage AES-256 digital voice encryption to stop unauthorized listeners from recording or streaming us without our consent. It has had a major benefit to our group. We are only required to provide service to those licensed to operate in the Amateur Radio Service (in Canada). Our law is worded as such: "You may not use a code or cipher that is SECRET". Once we share it with authorized persons, it's no longer a secret. Our government agrees with us.

I'm sure there's more reasons.

 

[WB6WQF]

I apologize if any of this has been said before but I don't see why there is such an anti-trunking sentiment. Anyone who uses a DMR repeater on Brandmeister is getting a taste of trunking. Yes, there is only one RF channel but it is being shared by two timeslots. Expand the system so that it also shares multiple RF channnels and voila. Trunking would be great for some of the crowded repeater systems so that you can talk to your buddy without having to listen to all of the crap. Sure, you might not get a channel grant if the system is really busy but you would have a better chance of using the system than with a single RF channel.

 

[WB6WQF]

It has already been done. It wasn't hard. Acquire repeaters. Flash with Linked Capacity Plus. Install microwave backbone (way easier than it sounds, and not expensive -- just time and a few headaches). Connect sites. A few remote sites connect via Internet, but they're not as reliable due to UDP/packet loss when people are watching porn and Netflix at peak hours.

In terms of a need, here goes: (point form)

- As stated multiple times, with timeslot-trunking, there's no timeslot-strapping, which ties up resources (voice channels, aka "rest channels" in Moto-speak) system-wide.

- With Linked Capacity Plus (and other trunking formats), talkgroups can be programmed into the controller with routing settings. That means we can have wide-area groups, or groups that bring up certain sites only. Or, just simple "local" talkgroups which only involve activity on the site they originate on.

- We can send out-of-band (not on active voice channel) data, such as Radio Check commands, Call Alert, individual or group text messaging or security packets, such as Radio Disable/Enable, if a radio goes missing.

- We can control who accesses the system via Restricted Access to System (RAS), which is essentially infrastructure protection. It keeps CCRs and improperly programmed radios off the network. It is not encryption. (But we run encryption anyway, because we can)

- Repeater health monitoring via admin software. We can check VSWR, voltages, power output, temperatures, power status (AC or battery backup), control channel status (revert one or many repeaters into analog service, if required for ARES whackers), etc. Admins get instant emails if a site sends out any error message. I don't know of any ham analog CSQ setups that do that.

- We get two talk-paths for each physical repeater at a given site, with a maximum of 16 timeslots per-site. Can't do that with DSTAR, Fusion or P25 (without a trunking controller, which also ties up an RF frequency as a dedicated control channel at each site).

- We have a log of every PTT access on our system. Useful for troubleshooting. We can disable/block Radio IDs if needed (stolen, someone drunk, etc.)

- A site goes down (on IP), and the rest of the network stays together. This includes the master site. In the analog world, if the hub site went down, your backbone would fail.

- Consistent audio quality across our entire network. No problems with distortion/poor levels. Anyone who wants to argue this obviously hasn't optimized their MOTOTRBO subscribers with the latest firmware/enhancements. I had a large role in that process, back in 2015.

- The ability to engage AES-256 digital voice encryption to stop unauthorized listeners from recording or streaming us without our consent. It has had a major benefit to our group. We are only required to provide service to those licensed to operate in the Amateur Radio Service (in Canada). Our law is worded as such: "You may not use a code or cipher that is SECRET". Once we share it with authorized persons, it's no longer a secret. Our government agrees with us.

I'm sure there's more reasons.

Those are all excellent points. I would help finance a system with those capabilities since the benefits are enormous. Of course there could be issues using encryption in the US but everything else can be implemented and, when it comes to encryption, where there’s a will there’s a way.

 

[kb6hlm]

Anyone remember the old analog trunking on the cellphone 800 band ? you would get one of those interesting conversations and then it would just drop off then you had to start scanning up and down the band trying to find them again That drove me nuts ! LOL I remember just using a UHF TV to do that anyway....... those good old days are gone but thats OK the new age is here

I support Ham Radio trunking, Do you ?
Mars_P25
Very nice work! its just to bad that the US is so far behind in technology IE : Ham SAT TV/ 4K satellite TV just to name a couple
keep up the nice work you are a breath of fresh air and just ignore the NAY saying out there

KB6HLM
"A closed mind is a terrible thing to waist"

 

[exkalibur]

Several people mentioned how to make repeaters ID properly.
I want somebody to tell me how to set up the user radios to ID each time they make a transmission on a different frequency.

Who cares? You don't need to identify on every frequency, only during the same conversation.

Plus, as Mars posted, identifying with voice is archaic and unnecessary. If you hear people talking and A) don't recognize their voice, B) aren't communicating with them or C) aren't trying to call "CQ" the solution is simple; Nunnya. The world isn't going to fall apart just because someone doesn't identify. Part 97 rules are old, archaic and outdated. They haven't gone lock-step with technology and in many respects hamper experimentation which is exactly what amateur radio is supposed to be. I'm not suggesting throw your hands up and abandon the rules by any means, but be realistic about it and realize that you're in a hobby of free experimentation. Keep the spirit of the law in mind and no judge is going to convict you. Use the W6NUT repeater as a display of how much the FCC cares about enforcing the rules.

 

[kb6hlm]

Maybe I should be locked up for monitoring cellphone conversions ? LMAO I agree with exkalibur the way of IDing is outdated to me anyway I would think there would be a way of IDing on a ham radio trunk system DMR/P25 or whatever repeater you use kind of like how the commercial guys do it (talk group ID/UID) maybe instead of a UID Number use your call sign ? with todays SDRs it should not be that hard to do I'm sure someone will come up with something ?

 

[AK9R]

Plus, as Mars posted, identifying with voice is archaic and unnecessary.

Identifying by voice is not required. You can identify by CW, voice, or RTTY. I know hams who spend a lot of time rag-chewing using AM or SSB, but you rarely hear them identify by voice. They have automatic CW IDer's connected to their mic inputs that transmit their callsign at a low level every 10 minutes. Perfectly legal under the existing FCC rules for amateur radio.

Part 97 rules are old, archaic and outdated.

If you feel this way, have you petitioned the FCC to change the rules?

 

[Mars_P25]

If you feel this way, have you petitioned the FCC to change the rules?

exkalibur and I are fellow hosers (Canadians). It's not our mission, per say.

W9BU, on a personal level, I just want to say thanks for being reasonable for having a good sense of humor and allowing some of this craziness and banter to continue, to an extent. I feel parties on both sides of this debate are having some good fun, even if we completely disagree on some subjects.

 

[AK9R]

In all this banter, I've lost track. Does the Canadian communications regulator permit amateur radio trunked radio systems? Have you hosers built an amateur radio trunked system in the Great White North? Where? What are the details?

 

[AB4BF]

I've given this Ham trunking thing a lot of thought (at least 20 or 30 seconds) and I think I might have a win win situation for all involved. I am all for Ham experimentation and another word I can't think of at the moment (innovation, I thought of it) and propose this...

Why not use the 1.25 meter band for all trunking use and experimentation? 222 to 225 MHz is rarely used, heck, Icom just came out with a new SDR radio that costs over $2K to purchase and they didn't even put 1.25 meter in it. (Maybe with an upgrade?)

Hams could perfect the trunking on the 1.25 band and then roll it out to other bands in the future. Another Ham I know well said the 1.25 M band just lends itself to handling the trunking signals well and there are no more restrictions on the band than any other VHF or UHF ham bands out there. We might think about this and try to keep our frequencies that the FCC may want to auction off...

 

[Skypilot007]

One big problem using 220MHz band is there are very little if any DMR Linked Capacity Plus equipment that operates in that band.

 

[AK9R]

What about the 902 MHz band? A handful of ops in Indiana are putting up 902 MHz P25 repeaters using surplussed Motorola equipment.

 

[kayn1n32008]

What about the 902 MHz band? A handful of ops in Indiana are putting up 902 MHz P25 repeaters using surplussed Motorola equipment.

Good call.

The only issue I see is all the unlicensed ISM (WISP) garbage on 33cm.


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[bill4long]

Good call.

The only issue I see is all the unlicensed ISM (WISP) garbage on 33cm.


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I mentioned this earlier. 33cm has a lot of spectrum. How hard could it be to find some useful slots? Where I live, there is a 900mhz group that has five receivers in a voting system and it works just fine. Using digital instead of analog would be good. May as well go all-out.

 

[Mars_P25]

I mentioned this earlier. 33cm has a lot of spectrum. How hard could it be to find some useful slots? Where I live, there is a 900mhz group that has five receivers in a voting system and it works just fine. Using digital instead of analog would be good. May as well go all-out.

Sorry, but 900 MHz is garbage in urban areas. In Canada, 902-928 is full of Industrial, Scientific, Medical (ISM) wideband wireless garbage. It went from being a stellar band with excellent propagation characteristics (I used P25 on 900 for years) to completely useless. The entire band is full of garbage. Just look at it on a spectrum analyzer or even a wide-band SDR from a decent repeater site with a high-gain omni at a few hundred feet. It's RUINED. The interference causes the noise floor to be about -90dBm and any weak signals are completely wiped out.

The only thing left to do is set up your ham repeaters to listen outside of the amateur radio service on the 901 MHz band, which falls just outside of the ISM area. Nice and quiet there. Just don't tell anyone. I blame our government for allowing 902-928 to become a massive clusterf$@!. The way I see it, they owe me a usable frequency.

As for 222-225, yeah -- not doable. There's no DMR, P25 or NXDN trunking gear which supports that band. And no, it's not feasible to convert 136-174 gear to 225, as it would take extensive modifications. The size of the surface mount components in these modern devices does not suit reasonable modification efforts.

We're talking 0402 and 0201 sizes. And there's no detailed service manuals which actually list the component values. Motorola intentionally obscured this information to prevent the chowderheads from cloning their 2.0 and 2.5 radios. Reverse engineering the RF circuits and matching networks would take some serious effort and dedication.

The most logical place for trunking on ham is 144-148 and 430-450 (maybe 420-450 in some areas) due to native support of existing commercial gear. And it's not like the trunking systems will consume nation-wide spectrum. We're talking 25-60 miles here in most areas -- maybe even less. No one post on Radio Reference is going to get a ham system shut down.