Re: [Discuss-gnuradio] USRP hardware purchase

[Dan Halperin]

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The USRP has a maximum bandwidth of about 16 MHz (using 8-bit samples
instead of the usual 16), which is not even enough to cover one
802.11b/g channel (22 MHz Nyquist). Thus you'll have a hard time
decoding b/g packets at faster than 1,2 Mbit rates (BBN has done some
work facilitating the recovery of these packets).

On top of that, an (extremely, I think) optimistic lower bound for
latency in a GNU radio system is over 1 millisecond from the RX antenna
through the FPGA over the USB to the computer to your software back over
the USB and out the TX antenna. This makes it _reallllllly_ hard to get
the 10 _microsecond_ turnaround required for an 802.11b ACK, and carrier
sense is meaningless with such a latency.

Also, see Tom Rondeau's email of 12/05/2006 for more comments, but the
short of it is that you're unlikely to be able to get any sort of
reasonable interoperation between the USRP and commercial 802.11b/g
hardware.

- -Dan
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