High BER on DMR

Help with DMR issues
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aa9vi
Posts: 11
Joined: Tue Sep 11, 2018 8:58 pm

High BER on DMR

Post by aa9vi »

Does anyone know what could cause and how to improve high Packet Loss on DMR? BER is at 0.0%. This seems to be a network issue since it is indicated on the Gateway Activity dashboard. I tried to change DMR servers and that did not help. Other digital modes do not have this issue. I am using a RPi 3B+ with the STM32 hat. I have upgraded Pi firmware and STM32 firmware to the latest versions. This has been an ongoing issue for some time.

I assume the (Packet) "Loss" indicated in the dashboard is purely network calculated. Is that right? I read from a previous post that increasing the jitter level by 200 may help? Can anyone elaborate?

Mike, AA9VI
M1DNS
Pi-Star Team
Posts: 1100
Joined: Thu Apr 05, 2018 5:30 am

Re: High BER on DMR

Post by M1DNS »

Yeah, BER is losses in the rf path.
Loss is, loss over the network path.


Try going into mmdvmhost expert page
Change jitter value to 600 -> Save changes.

../admin/expert/edit_mmdvmhost.php



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Andrew M1DNS.
Pi-star Admin Team.
aa9vi
Posts: 11
Joined: Tue Sep 11, 2018 8:58 pm

Re: High BER on DMR

Post by aa9vi »

BER is fine. The packet loss of 12-35% did not improve with a fiber link with very consistent ping times < 1ms. I tried to increase the MMDVM latency to 600 and that did not help. I suspect others may have seen an issue with a PiHat STM32/Repeater Builder MMDVM interface. Are there any other ideas out there?
M1DNS
Pi-Star Team
Posts: 1100
Joined: Thu Apr 05, 2018 5:30 am

Re: High BER on DMR

Post by M1DNS »

The hat won't have much of an effect on the packet loss. Loss is whats coming into you over ur network connection.

Hat is RF. If you had a high BER, that would be hat based.

look at ping times & packet jitter over and through ur network setup.

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Andrew M1DNS.
Pi-star Admin Team.
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