Hi there,
I’m facing a Streaming Buffer underrun error when I put both Galileo and BeiDou constellations to LEO. I tested the GPU and it scored 2.79, which is good. Please find screenshots of the error.
Kindly advise, I actually need a bigger constellation to orbit in LEO, it has been mentioned in one of the discussions that BeiDou satellites will be increased to 100, has that been done yet?
Hi Maria,
For now the BEIDOU constellation is limited to 63 SV.
Is the underrun error systematic? If so, can we have a screenshot of the performance graph and info on the config?
Regards,
Grace
Hi Grace,
Yes, it is systematic. The underrun error is there even when the satellites are in MEO. Here is a screenshot of the config and performance graph.
With regards to the BeiDou constellation, I can now see the 63 SV in Skydel Version 22.7.1.
Appreciating your help,
Regards,
Maria
Hi @Maria_Mohamad,
What platform are you using (GSG-8 or using your own hardware on Windows / Ubuntu)?
Regards,
Mathieu
Based on the slope of that green line, it looks like the streamer is running 60% slower than real time.
It just so happens that 50 msps IQ data is 1.6 gigabits per second, which is 60% more bandwidth than is available over a standard 1 Gig Ethernet connection.
Can you confirm if you have a 1 Gig or 10 Gig connection between your computer and the X300?
From the performance graph, the issue seems to be with the X300.
What value do you have in the USRP Frame Size preference?
It is recommended to use a value of 8000 bytes.
You can find this preference through the edit → preferences menu, in the USRP tab.
If I reduce this value I get the same behaviour you are observing.
If this doesn’t fix it, have you setup your network card following the procedure found in the section 7.2.1.3. Network Card Driver: 10 GbE Intel X520-DA of the user manual? You have to make sure to set the “MTU” size to 9000.
Hope this help,
Best regards,
Mathieu
