DSDPlus DSD Plus Fastlane Missing Voice Traffic

[Clear4Code7]

I've been using DSD Plus Fastlane for a bit over a year to monitor a NEXEDGE 4800 site and have always had issues missing traffic on the voice channels since the beginning. I always have it set to hold on a specific talk group, yet I'm missing over 80% the voice transmissions.

When traffic is missed, the control channel shows a talk group assignment and radio ID, but the FMP24 window for the voice SDR sits at idle. It doesn't even attempt to follow the voice channel assignment. I'm using the following setup:

1. Dedicated SDR for control channel and dedicated SDR for voice channel
   1. I've tried swapping SDRs between control and voice to rule out antenna or other SDR issues. Behavior is the same regardless of which SDR/antenna is assigned the control channel vs voice channels
   2. When voice traffic is followed (roughly 20% of the time), the FMP24 VC output window tunes without errors in the bit stream. Voice audio is clear without drop-out or distortion from missed frames.
   3. Signal strength on both control channel and voice channels is strong (both using gain of 49.6), but not excessive. Current bandwidth setting is 4 on both SDRs.
2. DSD+ and FMP24 Settings:
   1. FMP24 window indicates both SDRs are Rafael Micro R820T
   2. Using direct link between FMP24 and DSD+ (on both VC and CC SDRs)
   3. DSD configured to only decode NXDN4800. All other protocols disabled
   4. Noise filter and shaping filter enabled
   5. DSD output windows show no errors in either VC or CC
3. Running Windows 10 Home Edition, Intel i6700 processor with 16GB ram.
   1. Task manager never shows FMP24 or DSDPlus exceeding 1% of CPU or consuming more than 24MB of memory
   2. Overall system CPU utilization sits around 6 to 7%, memory usage around 50%, and disk utilization 0 to 1%
4. Using SSD for OS and user partitions, but DSD+ is run off magnetic disk. Windows Resource Monitor shows very low disk utilization on the DSD+ drive (usually 0.00 to 0.01 queue length)

Anyone experiencing similar issues? It doesn't matter whether the transmission is 1s or 10s (as per the CC), the FMP24 window just sits at idle with no attempt to tune to the voice channel.

 

[Clear4Code7]

Here are the versions I'm currently running by the way:

• DSDPlus: 2.303
• FMP24: 2.71

 

[sonm10]

NXDN requires the voice frequencies to be known as well as the corresponding Channel numbers. You should edit the .FREQUENCIES file and follow the very specific syntax. Need to edit .NETWORKS, .SITES, .SITELOADER, .GROUPS files also.

 

[Clear4Code7]

I'm not quite sure what the correct term is, but the NXDN system I'm following somehow transmits the frequency data. For example, my .FREQUENCIES file is empty, yet DSD+ populates these as talk groups are assigned:

 

[slicerwizard]

Here are the versions I'm currently running by the way:

• DSDPlus: 2.303
• FMP24: 2.71

Those are both quite old. I'd start by getting up to date copies. You should be able to do that via the Misc menu.

 

[thewraith2008]

Signal strength on both control channel and voice channels is strong (both using gain of 49.6), but not excessive. Current bandwidth setting is 4 on both SDRs.

A gain of 49.6 is to high for RTL dongles. 28 is the normal in most cases.
You should adjust the gain to the point where the noise floor just starts to rise.

 

[sonm10]

Also, try only a single dongle. Use 1R and FMP24-CC. Get it working, then you can try adding the second dongle. The only advantage in two dongles is prioritized trunk tracking.

 

[Clear4Code7]

Hmm, I have it set to automatically check for updates. When I manually check, I'm always getting update available for 2.395, yet it never seems to take:


This downloads a DSDPlus2p395.zip to the DSDPlus Fast Lane folder, but it doesn't seem to do anything after. I can't manually extract it since it's asking for a password. Any ideas?

 

[cg]

First, back up your data...
Look in the DSDPlus folder for the 2.395v zip file
Unzip the downloaded file using the password given to you when you subscribed.
If unzipped to a different folder, paste the files into the DSDPlus folder

 

[Clear4Code7]

Oh wow, this entire time I thought the automatic updates downloaded and installed the files. Oops.

 

[Clear4Code7]

I've updated to DSDPlus 2.395 and FMP24 2.81 and tried running it with a single SDR in combined CC/VC mode, but it still frequently missed voice traffic.

The behavior is still the same where the CC shows talk group assignment, but it rarely even attempts to tune to the talk group. The vast majority of the time, it remains camped on the control channel. In some rare instances it will follow the talk group and work properly, but that's probably 20% of the time.

 

[mtindor]

I've updated to DSDPlus 2.395 and FMP24 2.81 and tried running it with a single SDR in combined CC/VC mode, but it still frequently missed voice traffic.

The behavior is still the same where the CC shows talk group assignment, but it rarely even attempts to tune to the talk group. The vast majority of the time, it remains camped on the control channel. In some rare instances it will follow the talk group and work properly, but that's probably 20% of the time.

Do you have both of these enabled:

Control --> CC/VC Combined Monitor
Control --> Voice/Data Call Following

Also make sure you don't have any talkgroups locked out for that system, or any weird priorities set up for particular talkgroups

 

[Clear4Code7]

Yes, both were enabled. It would follow some traffic, but missed around 80% of it. I would assume if the settings were incorrect that it would just not follow any traffic?

I also tried reducing the SDR gain to 28, but that introduced some additional decode errors. Although I don't think it's signal related since the problem is the voice channel not even attempting to tune to the talk group.

I did notice "traffic" files being created and removed in the DSD folder, leading me to believe the FMP and DSD link is file based rather than "direct". I'm going to try switching to TCP since file-based IPC is not reliable and would degrade my drive if I later switched to SSD.

 

[Clear4Code7]

Things are looking very promising with the TCP link. I've only been running it a few minutes, but so far not a single transmission has been missed. In the direct mode, I would have missed at least 5 voice channel assignments by now.