I’m going to be hacking carrier sense in to the FPGA on the USRP2 very
soon. Basically, taking what I did with the “in-band” project from the
USRP1 with carrier sense, and moving it forward to USRP2.
The idea is, just like you can set a timestamp to “gate” a packet on its
way out: only transmit it at time X, you can do something similar with
carrier sense. If the burst has the carrier sense flag set, then you
for the carrier to become idle, then transmit the packet.
For the in-band implementation, I had a command to set the value at
the carrier is determined to be busy/idle. This was stored in memory in
the FPGA. Then, when bursts came with a carrier sense bit set, that
OK: so I’d like to re-do this implementation to keep this kind of stuff
alive, and I will use it myself. But in doing so, I’d like to implement
in a way that jives well with the higher ups. If I’m going to do it,
like to do it right so that it lives on through future versions of GNU
Radio. So that means doing it using UHD.
For the life of me, I can’t find the UHD header spec. But I imagine
somewhere in there we can fit a bit to gate based on carrier sense, and
new command to set the carrier sense threshold.
If you have any advice/guidance on how you’d like to see this
let me know. I sincerely would like this to live long and prosper in
Radio and the USRPs.