Re: [Discuss-gnuradio] GNU Radio / Software Radio conceptual question

[Martin Braun]

On 17.06.2014 13:52, Sylvain Munaut wrote:
> > To me, the wrapping and passing of digital samples seems to put a
> > stack within the stack. The ends of the chain are unaware of the internal
> > message passing and act as if the samples were directly passed to the DAC
> > and ADC, ...
>
> Yes, and ? These are un-related stacks.
>
> Some highend DAC/ADC have high speed serial interfaces and
> encode/packetize the data before sensing them to the CPU/FPGA/ASIC
> that will deal with the samples, would you consider that a PHY
> emulation as well ? The way the samples are transported from one
> endpoint to the other is largely irrelevant here ...

I agree, this is the point I was trying to make. Somehow, the samples 
have to get from the ADC to the PHY. In the case of a networked device, 
it's by Ethernet. On an embedded device, there might be an AXI connection.

The PHY is where the physical signal is handled (or samples in case of 
digital systems), hence the name, regardless of where the samples are 
from. Of course Ethernet has its own PHY and MAC, but our comms system 
doesn't care about this.

M