Re: [Discuss-gnuradio] USRP2 / Tunnel.py packet reflection issue

[Marcus D. Leech]

On 10/31/2011 06:40 PM, Tuan (Johnny) Ta wrote:
> Marcus,
>
> What do you mean my zero-stuffing the TX frames? And how would it help 
> with the turn-around time of the XCVR2450 daughterboard? Do you mean I 
> should transmit a zero-filled packet before any real packet, so that 
> the receiving side (A in my scenario) has time to switch back to 
> receiving before the real packet arrives?
The transmit side assumes that the combination of RX-to-TX and TX-to-RX 
transition experienced by both sides is non-zero.  So, you get
  the transmit side to simply send some idle 0s, and *then* the actual 
start-of-frame data, etc.  What happens in these situations in my experience
  is that the start-of-frame gets missed during the switchover 
interval.  So if the transmit side sends zeros (or, really, anything 
other than
  the start-of-frame sequence) for a "little while" after commencing a 
transmit burst, you're less likely to run into TX-to-RX transition issues.


--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org