Setting Up “All Call” on Hytera DMR Repeaters and Handhelds

[nikga123]

I’m trying to determine how I can configure an “all call” on my current Hytera DMR setup, or what steps I should take to reconfigure my repeaters to make this possible.

Here’s what I’m working with:

Repeaters: 2 x Hytera RD982 (not networked or linked)

Handhelds: X1e, PD602i, PD502i, PD362i, PD362 - of varying quantities (I am pretty sure all can do all call encodes and decodes)

Mobile: MD782

Current Setup:

• Both repeaters are physically located next to each other but operate on different frequencies.
• Each repeater is set up with two channels (one per timeslot).
• No pseudo-trunking in use. (Seems to be a purely conventional setup.)
• Repeater A and its channels use one encryption key, while Repeater B uses a different key.
• Most of the handhelds are programmed with at least three of these channels.
• This setup was inherited. It wasn’t planned or configured by a professional, and I suspect it’s far from optimal.

What I’d like to do:

I want to implement an “all call”, if I can, to broadcast a message from one handheld or mobile that will be heard by all users on both repeaters.

Questions:

1. Is this possible with the current setup (i.e., two unlinked repeaters)? (I assume the answer to this is "no".)
2. Is it a matter of configuring the “All Call” group correctly, or would I need to rework the way the repeaters are set up?
3. Would unifying the encryption keys help in making this possible? Does it matter?
4. Should I consider linking the repeaters, or is there a better way to achieve this?
5. I believe it is possible to interconnect frequencies by adding an HM7XX series mobile back-to-back with the repeater. Would this help in achieving my goal?

Any insight or suggestions would be greatly appreciated.

 

[racingfan360]

1. Are there any other material differences to the two repeaters in use beyond frequencies (eg coverage area etc?)
2. Have you the the ability to fully program each and every one of the radios in the system?

There are probably easier/better ways of doing it, I assume All Call would only work on one of your channels? You may be able to add a new Talkgroup (the 'All Call TG') to one of the existing channels/slots, add that to all radios, set each radio to scan this and its existing channel, but then set this new All Call TG channel as the Priority in the scanlist. Might need Priority Interupt Encode/Decode set too.

 

[nikga123]

Thank you for your answer.

1. Are there any other material differences to the two repeaters in use beyond frequencies (eg coverage area etc?)

No. They are literally right next to each other in every aspect. The antennas are within 5-10 feet of each other.

2. Have you the the ability to fully program each and every one of the radios in the system?

Yes, I have access to program the repeaters and all radios.

There are probably easier/better ways of doing it, I assume All Call would only work on one of your channels? You may be able to add a new Talkgroup (the 'All Call TG') to one of the existing channels/slots, add that to all radios, set each radio to scan this and its existing channel, but then set this new All Call TG channel as the Priority in the scanlist. Might need Priority Interupt Encode/Decode set too.

This is essentially what I set up, but scanning drains the batteries faster on the handhelds, which is a bit of a hassle. I would like to avoid scanning if possible.

 

[kayn1n32008]

Both repeaters are physically located next to each other but operate on different frequencies.

• Each repeater is set up with two channels (one per timeslot).
• No pseudo-trunking in use. (Seems to be a purely conventional setup.)
• Repeater A and its channels use one encryption key, while Repeater B uses a different key.
• Most of the handhelds are programmed with at least three of these channels.
• This setup was inherited. It wasn’t planned or configured by a professional, and I suspect it’s far from optimal.

Yep, I'd say it is far from optimal.

First, it's using 2 physical antennas, one for each repeater. It *should* be set up so the repeaters are combined to use:
-One antenna for transmit and one antenna for receive.

OR

-One antenna for both repeaters, both transmit and receive.

Actual frequencies in use will determine which method to use.

What I’d like to do:

I want to implement an “all call”, if I can, to broadcast a message from one handheld or mobile that will be heard by all users on both repeaters.

Questions:

1. Is this possible with the current setup (i.e., two unlinked repeaters)? (I assume the answer to this is "no".)

No. You, currently, would need 4 radios. One for each timeslot.

1. Is it a matter of configuring the “All Call” group correctly,

No. Not that simple

1. or would I need to rework the way the repeaters are set up?

Yes, but it's not that simple.

1. Would unifying the encryption keys help in making this possible?

Yes.

1. Does it matter?

Yes.

1. Should I consider linking the repeaters, or is there a better way to achieve this?

If you want to implement All Call, using a single radio to be heard by everyone at the same time, using a form of trunking would be the way to do it. I'm not super familiar with Hytera Psudeo Trunking, however I am familiar with Motorola Capacity Plus Trunking and you can absolutely do an All Call. I would imagine Hytera has a similar method to be able to do an All Call on a Psuedo Trunking, multi channel system.

1. I believe it is possible to interconnect frequencies by adding an HM7XX series mobile back-to-back with the repeater. Would this help in achieving my goal?

Absolutely NOT. DO NOT do that.

If you want to link DMR repeaters, do it via IP. Much simpler, and it will actually work.

Any insight or suggestions would be greatly appreciated.

Hope this helps. I have zero knowledge of what the portable radios you have for capability. I don't use Hytera at all.

 

[nikga123]

Yep, I'd say it is far from optimal.

First, it's using 2 physical antennas, one for each repeater. It *should* be set up so the repeaters are combined to use:
-One antenna for transmit and one antenna for receive.

OR

-One antenna for both repeaters, both transmit and receive.

Actual frequencies in use will determine which method to use.

One thing I forgot to mention, though this might be obvious, is that each repeater currently has a single antenna of its own with a duplexer. Maybe obvious, maybe not, but I thought I'd mention it.

So you are saying I should be linking these together with IP. I would still want to keep both my current frequencies. Not sure if that is possible.

Absolutely NOT. DO NOT do that.

I see. I am very interested why this is such a no-go. (And the only reason I ask is because Hytera promotes this as a feature with their HM782 mobile.)

Hope this helps. I have zero knowledge of what the portable radios you have for capability. I don't use Hytera at all.

Much appreciated. Thank you.

 

[buddrousa]

Your answer comes from a user that does this type work. You have been given the best advise not sure why you question the person that gave you advice. It is very obvious that you are way over your head. When you start making big changes to systems you need to apply for license changes and possibly other changes.
I have 1 question. Is this used for Public Safety or Life Safety use (Fire EMS Rescue)?
If the answer is yes you need to hire licensed 2way radio shop if not you will be held responsible if the system fails to operate properly?

 

[kayn1n32008]

One thing I forgot to mention, though this might be obvious, is that each repeater currently has a single antenna of its own with a duplexer. Maybe obvious, maybe not, but I thought I'd mention it.

That is exactly what I figured. Cheaper to buy 2 crappy antennas(I'd guess either unity gain or 3dB fiberglass), and 2 crappy duplexers(I'd almost put money on them being a mobile notch only duplexer), rather than buying a proper filtering system.

So you are saying I should be linking these together with IP. I would still want to keep both my current frequencies. Not sure if that is possible.

You can definitely keep your frequencies if you link via IP.

I see. I am very interested why this is such a no-go. (And the only reason I ask is because Hytera promotes this as a feature with their HM782 mobile.)

You are adding unneeded RF into an environment that doesn't need more RF. Plus it is cheaper to link with CAT6 than it is with (an) additional radio(s). Dealers want to maximize profit. They make far more profit off radios than they do CAT6. They are trying to balance the line of selling as much as the client will buy, with out having the client just not buy at all.

I can think of a few industrial sites that got suckered into single site Connect Plus trunk systems, when single site Capacity us would have been more than adequate.

The difference is, Connect Plus requires additional equipment, beyond the repeaters and RF plumbing to make it work, where Capacity Plus only needs a switch and 2 CAT5e cables to connect the repeaters together.

Much appreciated. Thank you.

An additional questions would be, are these repeaters used for capacity(needing more channels) to cover the physical area? Are they physically located in the same place?

Do you have pictures?

What band and how close are the frequencies to each other?

 

[nikga123]

Thank you for all of your answers.

You are adding unneeded RF into an environment that doesn't need more RF. Plus it is cheaper to link with CAT6 than it is with (an) additional radio(s). Dealers want to maximize profit. They make far more profit off radios than they do CAT6. They are trying to balance the line of selling as much as the client will buy, with out having the client just not buy at all.

I can think of a few industrial sites that got suckered into single site Connect Plus trunk systems, when single site Capacity us would have been more than adequate.

The difference is, Connect Plus requires additional equipment, beyond the repeaters and RF plumbing to make it work, where Capacity Plus only needs a switch and 2 CAT5e cables to connect the repeaters together.

Thank you for explaining that. Appreciated. I'm glad I asked about this before making a purchase.

An additional questions would be, are these repeaters used for capacity(needing more channels) to cover the physical area? Are they physically located in the same place?

Do you have pictures?

What band and how close are the frequencies to each other?

Yes, for capacity mainly, but also because there are basements and obstructions and whoever decided to buy the repeater wanted better coverage. The antennas are mounted at the top of a 150 foot tower.

I could possibly arrange photos.

UHF band. The Rx frequencies of each repeater are 1 MHz apart with each Tx having a 5 MHz offset from the Rx.

I hope the above answers your question sufficiently.

Thanks again.

 

[kayn1n32008]

I would suggest determining if the radios you currently have deployed are cable of Psuedo trunking, and if they are, determine if the repeaters are capable of it, with out purchasing upgrades.

If they are, start by creating a Psuedo trunking system on paper, and creating a new zone for it.

In that zone, have each of your 'channels' that duplicate the existing function
(For explanation only, your names and Talkgroups will be different)

Existing Conventional zone:
RF channel 1 TimeSlot 1: TG10 Security
RF channel 1 Time Slot 2: TG20 House keeping
RF channel 2 Time Slot 1: TG30 Operations
RF channel 2, Time Slot 2: TG40 Maintenance

New Psuedo Trunking Zone:

Create and define the trunking system frequencies amd slots for "Trunk System Site 1":

RF Channel 1, TS1
RF Channel 1, TS2
RF Channel 2, TS1(logical Slot 3)
RF Channel 2, TS2(Logical Slot 4)

Then create your Trunking personalities where you tie the trunking system parameters to a channel, then define the Talk Group

CH1: TSS1, TG11 Security
Ch2: TSS1, TG12 Housekeeping
Ch3: TSS1, TG13 Operations
CH4: TSS1, TG14 Maintenance

For All Call, there should be a list on each channel, that the radio will unmute to in addition to the talkgroup the channel is programmed to receive and transmit on.

Add a dedicated ALLCALL talkgroup for this example TG100.

Do not add that contact to the channel knob, but only list it on each channel positions rx group call list, or what ever Hytera calls it.

In the subscriber radios you want to be able to make AllCalls from, add it to a channel position.

Because Psuedo Trunking dynamically assigns a RF channel AND time slot, based on system loading, every radio should* tune to it, when a call goes over the all call personality. You may need to designate it as a priority channel, and have priority interruption enabled on the subscribers for it to function. You also will not have to have the eadios scanning for it to work.

You can also have unique encryption keys and Key IT'S for each channel if you want.

Write the new codeplug to the subscribers and do a training day(s) so everyone knows how to switch to the new zone on your go live day.

Then create the Psuedo trunking system for the repeaters, set up the IP link, and when it's slow, change the repeater programming, test it, then get everyone to switch to the new zone.

If this seems confusing, it is best to get help from someone who is competent working with Hytera, and Hyter Psuedo Trunking to make sure it goes smoothly.

 

[nikga123]

If this seems confusing, it is best to get help from someone who is competent working with Hytera, and Hyter Psuedo Trunking to make sure it goes smoothly.

Not confusing at all. Thank you very much for your time and helpfulness and for laying it all out..

 

[nikga123]

Your answer comes from a user that does this type work. You have been given the best advise not sure why you question the person that gave you advice. It is very obvious that you are way over your head. When you start making big changes to systems you need to apply for license changes and possibly other changes.

I understand. And I meant no offense. I was just trying to understand the full meaning, not trying to argue or challenge.

I have 1 question. Is this used for Public Safety or Life Safety use (Fire EMS Rescue)?

No. Private use (business radios).

 

[buddrousa]

I just make sure people that get into this understand it has to work 100% everytime.
40 Years as a Public Servant I just want everybody covered.

 

[kayn1n32008]

Not confusing at all. Thank you very much for your time and helpfulness and for laying it all out..

I forgot to add, once everything is up amd running, if you have time, cycle tye radios through and delete the old programming, so you onpy have tue trunking channels programmed. That way, someone can't accidently change zones, and be trying to use the old channels.

 

[nikga123]

I just make sure people that get into this understand it has to work 100% everytime.
40 Years as a Public Servant I just want everybody covered.

Thank you. I respect that.

 

[nikga123]

I forgot to add, once everything is up amd running, if you have time, cycle tye radios through and delete the old programming, so you onpy have tue trunking channels programmed. That way, someone can't accidently change zones, and be trying to use the old channels.

Right. Makes sense. Thank you again.