Re: [Discuss-gnuradio] High packet loss problem (samples dropped?) and fusb parameters

[Hsin-mu Tsai]

On 7/25/07, Dan Halperin <address@hidden> wrote:

<deleted>

> IIRC 802.15.4 is a 2 MHz (if you think of it as QPSK at twice the symbol
> rate, that is) modulation scheme so this is going to be testing the
> limits of USB if you sample at 2 4, or 8MHz complex (8, 16, 32 MBps
> respectively). Have you benchmarked your USB speed (I think
> gnuradio-examples/src/python/usrp/benchmark_usb is the accepted way to
> do so these days)? Are there other USB devices attached to the computer?

I suspect the problem is somehow related to USB too. But I couldn't
figure out a way to isolate the problem. Could the interrupts
generated by the USB controller be lost in the OS? (I thought it's
reliable, but I'm not sure)

I removed all the USB devices from the computer when I was doing the
experiment. The benchmark script said 32 MB/s throughput can be
achieved.

Thanks,
-Michael

--
Hsin-Mu (Michael) Tsai
Ph.D. Student
Electrical and Computer Engineering Department
Carnegie Mellon University
E-Mail: address@hidden
Web: http://www.ece.cmu.edu/~hsinmut/
Office: +1-412-268-4639