On Thu, May 24, 2012 at 10:27 AM, Pan, Luyuan<address@hidden> wrote:
Hello,
I want to use my USRP2 to implement a TDMA system, and I want to send 5
seconds, receive 5 seconds, and do the recycle. I used the stream tag demo
in gr-uhd/taguhd. The question is:
1. As sean have said in
http://lists.gnu.org/archive/html/discuss-gnuradio/2012-04/msg00506.html we
should use "tx_time", "tx_sob" (start-of-burst), and "tx_eob" (end-of-burst)
to tag the data flow, but yend B in
http://www.ruby-forum.com/topic/3832986 said the data not enclosed by
sob-eob tag pair was dropped. Is this problem really exist? And any
solution?
2. Is there any way to switch the Tx/Rx? And how to tell the USRP to receive
for a desired time slot such as 5 seconds then stop? The only parameter I
can see in gr_uhd_usrp_source is 'rx_time'(tells when to start receive), I
do not know how to stop the streaming after 5 seconds.
Thank you for your help. Any suggestion is appreciated.
--
Best regards,
Pan, Luyuan
It sounds like you need to add a rate control to your MAC layer.
Obviously, when you aren't transmitting, you don't want to be
generating any samples. You'll need to buffer them. This is going to
take some work outside of GNU Radio to create an app that has a thread
to control the samples and pass them to a message source block in GNU
Radio.
I'm not sure there's a good example of this, and we don't really have
a 'best practices' for this right now.
Tom