Re: [Discuss-gnuradio] Gig-E alternatives & dual USB2

[John Gilmore]

> The other thought is that if you are considering putting the peripheral 
> remotely close to an outdoor antenna, perhaps an optical fiber solution 
> would be better - why risk frying your CPU or your body?

Copper GigE is sufficiently cheap and ubiquitous that a DAC/ADC board
should use it.  But for the people who want to mount the whole thing
on a tower and run a nonconducting fiber back to their processing
shack, a converter from copper GigE to fiber GigE is small, low power,
and only costs a few hundred dollars.

> Though GigE sounds like a good idea to pursue, has anyone thought about 
> using 2 or more USB 2 interfaces as an alternative?

A good hack!  I don't know if common multi-USB2 host interfaces can
run all the ports at top speed simultaneously.  Some look to software
like a single interface connected to a hub.

I wonder if we could make a "Second USB2" daughtercard that would use
some of the FPGA's digital I/O pins to drive another USB2 chip?

(The protocol over the USB would need to change to add packet numbers, or
to otherwise provide for a way to synchronize the two streams; but this
is probably a simpler change than making a GigE interface.)

        John