Re: [Discuss-gnuradio] Idea of a USRP UHD block that fills gaps in transmission from USRP

[Matt Ettus]

That's true.  You can fix some of the issues by using preemptible kernels and setting RTPRIO, but there can still be glitches.  Certainly a block which reads the streams tags and inserts zeros would not be too hard.

Matt

On Thu, Feb 13, 2014 at 10:20 AM, Sylvain Munaut <address@hidden> wrote:

Hi,

> One problem is that if you cannot keep up, adding in all-zeros data will
> just make it harder to keep up.  In general, modern PCs should be able to
> keep up with 25 MS/s without problem unless you are doing a lot of
> processing.  We are actually able to keep up with 300 MS/s on the X300.  So
> the question is more about why the app can't keep up.

Well, sometimes the issue isn't so much throughput but latency. Like
you have some ultra high priority task that decides to block all
processing for like 100 ms and some buffer fill up and you miss one
packet ever few minutes. I have that kind of stuff all the time on a
USRP1. It's not a real time OS so it's always better IMHO to be able
to cope gracefully with theses little glitches.

And if you're app expects a continuous stream of data to maintain
alignement, filling with zero is easy enough.

Cheers,

    Sylvain