RE: [Discuss-gnuradio] Predictable latency?

[Geib, Jeffrey (Civilian)]

On Tue, Aug 19, 2008 at 10:27:15AM -0400, 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?  
> 
> Thanks!

Latency measured relative to what?
Rx only, Tx only or Tx/Rx?

Eric

I am looking for fixed latency from Rx to Tx.  I want to take a
continuous stream of input data, process it, and transmit it back out.
The processing needs to know what the precise latency is between the
samples at the DAC and ADC.

>From the previous replies and Thomas Schmid's analysis, it appears that
this isn't feasible with the current interface.   It appears this could
be done with the mblock and inband signaling additions, where then I
could schedule each packet to be output at a known timestamp. 

Jeff