Re: [Discuss-gnuradio] Latency on TX for low data rate systems

[Eric Blossom]

On Mon, Dec 03, 2007 at 01:14:29PM -0800, Eugene Grayver wrote:
> Hi Eric,
> 
> I cannot reduce the sample rate at the sink since there are additional 
> signals being added to the FSK.  The FSK transmitter is bursty -- there 
> will be no data for long periods of time, followed by a few bits of data. 
> E.g. a udp packet comes in and needs to be sent out.  I was considering 
> using the gr_throttle block, but it will not give me the desired result. 
> Even if the throttle rate is slightly different than the actual TX rate, 
> the intermediate buffers will eventually either underflow (unacceptable) 
> or fill up, resulting in the same latency issue.
> 
> I am considering a minor change to the gr_single_threaded_scheduler such 
> that the min_available_space returns not the actual available space, but a 
> min(min_available_space, max_buffer_depth), where max_buffer_depth is a 
> block-specific parameter.  Naturally, I would rather not do major surgery 
> on the runtime blocks, but I can't think of any other solutions.
> 
> Thanks,
> Eugene.

OK, that makes sense.

Eric