Re: [Discuss-gnuradio] updated packet format on USRP inband signaling

[Eric Blossom]

On Sun, Feb 25, 2007 at 07:29:01PM -0500, Brian Padalino wrote:
> Some preliminary questions:
> 
> How are the operations linked with the transmit sequences?

I'm not sure I understand this question.  

> Are operations sent down in bulk, or one at a time?

You can send as many as will fit in the payload.
Unless you doing something like hopping, I suspect that command
packets are relatively infrequent.

> Will the RX chain simply start and return 504-byte length packets
> until the next TX timestamp is sent down?

I think this depends on how everything is configured.  I think you'll
have to do something (set some register) to enable the Rx at all.
Likewise for Tx.  As to how the Rx and Tx interact, I think that's
still to be worked out.  The right answer may depend on the
application.

E.g., a half-duplex "push to talk" radio (simplex or trunked) would
probably run the Rx all the time, except when it was transmitting.

A packet based radio may run some power measurement / RSSI code in the
FPGA and only return Rx data when it wasn't transmitting and the power
exceeded some threshold.

> Could this starve the USB bandwidth?

Only if the sum total of IN + OUT is > 32MB/s

Eric