This is correct. Your samples go through buffers, and therefore it is hard to predict the latency each and every sample will have to get from software to the USRP. I did a study on this a while back. If you are interested, you can find the paper here: http://nesl.ee.ucla.edu/document/show/242
What you can do though is calculate the minimum and the maximum latency that the samples will have. Also, I am not sure how far the mblock and GNU Radio is in regards to timestamping outgoing samples (I didn't follow the GNU Radio development lately) is, but if you can tell the USRP when to send out which sample, then you could easily predict the latency itself. Cheers, Thomas On Tue, Aug 19, 2008 at 8:14 AM, Chris Stankevitz <[EMAIL PROTECTED]> wrote: > > > Geib, Jeffrey (Civilian) wrote: >> >> I have an application where I don't necessarily care what the latency >> is, but I need it to be predictable and/or constant. Is there a way to >> achieve this with the USRP hardware? > > USRP supplies data via USB. I believe the delay of USB data through the > operating system and into your application is not predictable or constant. > > Chris > > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > -- "Don't complain; Just work harder" - Randy Pausch Thomas Schmid, Ph.D. Candidate Networked & Embedded Systems Laboratory (NESL) University of California, Los Angeles (UCLA) http://gresci.blogspot.com/ - Science articles on green technology _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
