ubalis
Hi,
1. In the instances where it does not bring up the hoseline or hotspot, it does not start up after a few seconds. It simply doesn't start at all. Also, I've noticed that when it doesn't work, it often doesn't work for successive iterations. So, for example, I'll have to key up five separate times until the hotspot starts responding. I'll generate a few examples and send you the log, as this problem is highly reproducible.
2. All the battery saving features are turned off.
Of note is the fact that the radio works perfectly with our local DMR repeater (a Motorola Mototurbo), but I suspect its still something about the CS750's non-standard preamble packets that the repeater doesn't check for.
Thanks for your continued efforts with this!
-ub
ubalis
Please find an extraction of the CSV log generated by the openSPOT2. The entries for which there is no communication to Brandmeister all have the common condition of generating a late entry message in the log. Is this somehow related to why these messages do not successfully propagate?
At To From EntryType Duration (s) BER (%) Loss (%) Avg. RSSI (dBm) Remarks
12/2/2018 22:39 312654 N4IYL Ulysses J (1126088) start 0 0 0 0 Group DMR voice call from modem
12/2/2018 22:39 312654 N4IYL Ulysses J (1126088) end 2.6 0.7 0 -59 Group DMR voice call from modem
12/2/2018 22:39 312654 N4IYL Ulysses J (1126088) start 0 0 0 0 Group DMR voice call from modem
12/2/2018 22:39 312654 N4IYL Ulysses J (1126088) end 2.9 0.8 0 -61 Group DMR voice call from modem
12/2/2018 22:39 312654 N4IYL Ulysses J (1126088) start 0 0 0 0 Group DMR voice call from modem (late entry)
12/2/2018 22:39 312654 N4IYL Ulysses J (1126088) end 2.1 0.4 0 -53 Group DMR voice call from modem
HA2NON
Thank you for the information. This suggests that the radio has no support for late entry. I can confirm this, as I tested it with an OS2 firmware where voice LC header send was disabled. So if the radio does not receive (or able to decode) at least 1 voice LC header then it is not able to decode the call at all.
By the way the CS750's menu and display exactly reminds me a Puxing DMR handheld I used for a short time several years ago. And it also did not support late entry like older Tyt radio firmwares (I don't know if they added late entry support in later Tyt firmwares).
We'll notify Connect Systems about missing late entry support.
ubalis
The late entry errors were happening when I was transmitting from the CS750 (and not receiving). Is this still the same issue?
The behavior would be that upon keying up the CS750, the OS would start receiving the packet steam, indicating a late entry error in the log, and the expected audio stream would not turn up on the hose line, nor would it be heard by others across the internet on various hotspots and repeaters.
Also, with further experimentation, I was able to make the problem occur much less frequently, by programming my router (Synology 2600AC) to prioritize the OpenSPOT packets with a minimum bandwidth of 10K/second (e.g. 100 kilobits) for both upload and download.
It's been challenging to troubleshoot the packet loss issues these past few days in the US, because, for whatever reasons, there seems to be an inherent instability in the overall Brandmeister network backbone. TAC-310, for example, will cut in and cut out on its hoseline, where only parts of a conversation can be received. I wonder if you are seeing similar continuity of service issues in Estonia?
HA2NON
The CS750 only transmits 1 voice LC header (as mentioned before) and if it's not received or decoded correctly by the openSPOT2 then the openSPOT2 will start the call with a late entry. One superframe in DMR is 360 ms long, and if all embedded data is decoded correctly then the call can start after that. If not, after the next superframe, and so on. If the OS2 displays a call start then from that point your call will be sent to the server.
You should use the openSPOT2's built-in echo service to rule out network issues.
ubalis
I have programmed the OpenSPOT's echo service into the CS750 and it works perfectly, with no packet loss.
However, when using the 9990 Brandmeister Parrot channel with the OpenSPOT, I receive late entry errors on a few transmissions (and no echo) and for those remaining transmission that do go through, there is modest packet loss in the echoed responses.
HA2NON
You should try using another server.
ubalis
I tried all the North American servers. 3101, 3108 and 3104 exhibited unacceptably high packet loss, as deemed by the poor quality of the echoed audio stream. 3102 was slightly better, so I'm using that server for now. Apparently, there has been some type of anomalous degradation in the Brandmeister network performance in the U.S. over the past week, but I so far have not been able to find a blog site or news site that describes what exactly is going on. From speaking with other fellow amateur operators, apparently, Connect Systems has greatly reduced support for the CS750 model, as they had indicated over a year ago that updated firmware would be posted quickly. Well, it's over a year later and a quick check of their website shows that the updated firmware is still not available. I think it's safe to say that the CS750 is beginning to look like an obsolete model.
My solution at this point will be to get a more recent DMR radio to use with your openSpot2 product, recognizing that the CS750 is where the defect rests. You have been very helpful and I greatly appreciate your investment in time. But, considering how much time has been spent by both your team and me, I think it makes sense to give up on putting any further effort in a radio model that does not appear to have continued support from its vendor.
The CS750 is still a perfectly useful radio for local Mototurbo repeaters -- it just doesn't work as a hotspot-compatible radio with the openSPOT2. You might want to place some documentation on your website that the CS750 exhibits greatly degraded performance with your hotspot, so others don't go through what happened to me.
Regards,
-ub
ubalis
As an epilogue to this thread, I just received the Anytone D878UV radio and it worked perfectly with the OpenSPOT2 on the first try. The OS works beautifully.
Having invested over 60 hours of effort into trying to get the CS750 to work, and not being able to get a resolution from Connect Systems in the form of an updated firmware version, I would offer that it makes much more sense to select brands other than Connect Systems, when then intended use is primarily communicating through your OpenSPOT2. It is ridiculous that a customer would have to spend so much time, only to find out that they have a defective radio that no longer seems to enjoy vendor support.
Ideally, you should post something on your website that indicates that the CS750 and CS800 radios are incomplete ETSI implementations and therefore not suitable for use with the OS2.