Hi Steve,
We certainly appreciate the work you've done (along with Thibauld et al.) towards the inband functionality!
Thanks! It's been a major group effort along with Eric, Thibaud, Leo, and Brian.
Anyway, we've found a solution that seems to work, although I'm having troubles testing it thoroughly. Basically, instead of having both the interleaving and non-interleaving functionalities available in the same rbf, we have made a new rbf that has all the USB packet/timestamp functionality but assumes symbol interleaving. For our applications, we don't anticipate needing the flexibility of independent transmit channels.
Okay, this sounds like a reasonable solution. I think that multiple RBFs is not a bad thing. Especially since its a functionality that is quite exclusive... i don't think its something you're likely to turn off and on in a single application. You should be able to do the interleaving at the host easily.
We're currently in the stage of writing the host code for using multiple USRPs. Previously, we had host code written to use the inband_2rxhb_2tx.rbf with both transmit and receive on a single USRP, and this was relatively successful. Our current strategy is a little ugly; we're modifying the inband code so that multiple USRPs are controlled with a single usrp_server. I realize this is not how the code was meant to be utilized, but we've got concerns about sending data (which is supposed to be transmitted simultaneously) to two independent usrp_servers and having them both arrive on time. This concern is exacerbated by a demo next month where we hope to use 4x4. So we are taking the safer, yet messier, route for the moment.
hmmmm yeah, it was meant to be 1 usrp_server to 1 usrp. I'm not sure you really need to do this. You just need to make sure that both USRP's clocks are synchronized. From that, the timestamp (which currently has some issues) should allow you to transmit simultaneously on both.
Anyway, I wanted to give you (and the list in general) a status update and let you know that we'll be happy to collaborate on anything regarding the inband code. Feel free to contact me and/or Ketan outside of the list as well.
Thanks Steve! I will probably keep in contact with you so that you can test some updates we have on the timestamp issue you found. I'm about to send another mail to the list about this.
- George _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
