Digital simplex and private calls.

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WA3FME
Posts: 21
Joined: Wed Oct 26, 2022 2:53 pm

Digital simplex and private calls.

Post by WA3FME » Sun May 07, 2023 3:28 am

So I have two md-uv390s and a dm1701 running opengd77. I've been trying to set up some digital simplex channels between them and when using group calls between them I have no issues. But if I try to setup a private call between two of the radios it seems 99% of the time the other radios pick up the private calls even after trying multiple different filtering methods. If anyone or the devs have any suggestions as to why I'm having any issue I'd be greatly appreciative of any advice as to what I'm either doing wrong if it's not really possible with the firmware that would be awesome. I understand dmr simplex and private calls between radios isn't really useful in the ham world I still have one or two uses for it. Sorry for the long winded post.

VK3KYY
Posts: 7478
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia

Re: Digital simplex and private calls.

Post by VK3KYY » Sun May 07, 2023 10:19 am

WA3FME wrote:
Sun May 07, 2023 3:28 am
So I have two md-uv390s and a dm1701 running opengd77. I've been trying to set up some digital simplex channels between them and when using group calls between them I have no issues. But if I try to setup a private call between two of the radios it seems 99% of the time the other radios pick up the private calls even after trying multiple different filtering methods. If anyone or the devs have any suggestions as to why I'm having any issue I'd be greatly appreciative of any advice as to what I'm either doing wrong if it's not really possible with the firmware that would be awesome. I understand dmr simplex and private calls between radios isn't really useful in the ham world I still have one or two uses for it. Sorry for the long winded post.
I don't understand your question

The firmware will receive all unencrypted DMR voice transmissions, regardless of whether its a Group Call or Private Call

WA3FME
Posts: 21
Joined: Wed Oct 26, 2022 2:53 pm

Re: Digital simplex and private calls.

Post by WA3FME » Sun May 07, 2023 1:23 pm

Sorry I wasn't able to explain better. I was wondering if theirs a way for me to have all the radios on a simplex talkgroup and be able to private call between different radios without the other ones hearing?

Like talkgroup 99 has radios 1 2 3 and 4 for example. I'm able to manually dial or switch to a private call between radios 1 and 4 but at the same time radios 2 and 3 are also able to listen. I was just wondering if I had the filters setup wrong? Or if it's norma.

VK3KYY
Posts: 7478
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia

Re: Digital simplex and private calls.

Post by VK3KYY » Sun May 07, 2023 9:35 pm

WA3FME wrote:
Sun May 07, 2023 1:23 pm
Sorry I wasn't able to explain better. I was wondering if theirs a way for me to have all the radios on a simplex talkgroup and be able to private call between different radios without the other ones hearing?

Like talkgroup 99 has radios 1 2 3 and 4 for example. I'm able to manually dial or switch to a private call between radios 1 and 4 but at the same time radios 2 and 3 are also able to listen. I was just wondering if I had the filters setup wrong? Or if it's norma.
No. There you can't prevent the other radios running the OpenGD77 firmware receiving your private calls.Or for that matter any other radios running other firmware set to promiscuous mode.

Just use 2 or more channels

We will also never be able to support encryption, as its illegal for the developers even to write encryption functionality , and generally illegal for Ham radio operators to use encryption

WA3FME
Posts: 21
Joined: Wed Oct 26, 2022 2:53 pm

Re: Digital simplex and private calls.

Post by WA3FME » Sun May 07, 2023 9:46 pm

Thank you. I appreciate all the work the devs have been putting into this great firmware.

ok1pt
Posts: 167
Joined: Mon Jul 20, 2020 3:38 am

Re: Digital simplex and private calls.

Post by ok1pt » Mon May 08, 2023 3:15 pm

VK3KYY wrote:
Sun May 07, 2023 9:35 pm
No. There you can't prevent the other radios running the OpenGD77 firmware receiving your private calls.Or for that matter any other radios running other firmware set to promiscuous mode.

Just use 2 or more channels

We will also never be able to support encryption, as its illegal for the developers even to write encryption functionality , and generally illegal for Ham radio operators to use encryption
Hi Roger and other devs!
Let me ask a stupid question: Why can't we implement Private Call filtering ? I believe that it's prefectly legal - it's just a digital equivalent of the private selective call on analog modes, and it's used frequently - it's very obvious to silently hang on a repeater and wait for a private selcall to answer and eventually start to communicate. And the logic implemented today (sorry, just now I don't have sources downloaded to consult them) seems strange - it looks that any DMR filter is now ignored for PC and it's always playing them, whle normally there should to play only those PCs which are targeted to my own DMR ID.
I think that the current implementation is, seen from a particular aspect, a step back from analog world, where private selcalls are accepted and used and very handy in some situations.

With regards / 73,
OK1PT

G4EML
Posts: 919
Joined: Sat Nov 16, 2019 10:01 am

Re: Digital simplex and private calls.

Post by G4EML » Tue May 09, 2023 10:30 am

I agree that the current handling of private calls is not ideal. We will look into this and see if it can be improved.


Colin G4EML

G4EML
Posts: 919
Joined: Sat Nov 16, 2019 10:01 am

Re: Digital simplex and private calls.

Post by G4EML » Sun Jul 02, 2023 10:43 pm

With the latest firmware release private call reception is now consistent with the DMR filter setting.

With DMR filter turned OFF you will hear all private calls.
With DMR filter set to TG or TGL you will only hear private calls addressed to your ID.

Colin G4EML

ok1pt
Posts: 167
Joined: Mon Jul 20, 2020 3:38 am

Re: Digital simplex and private calls.

Post by ok1pt » Mon Jul 03, 2023 5:10 am

Hi Colin,
thank you for this change. Now it's perfectly logical and easily configurable.
73 de OK1PT

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