Re: [Discuss-gnuradio] Physical layer for packet-based communication

[Rahul Dhar]

On Thu, Feb 03, 2005 at 08:49:37AM -0800, Eric Blossom wrote:
> Continuing on the packet comms thread, I'm investigating reasonable
> ways to get packets in and out of GNU Radio.  A couple of variations
> come to mind.  We could provide a fake ethernet or IP interface and
> allow external apps to push packets through that (similar to the click
> modular router).  The packets could be decorated with key/value pairs
> to provide attributes to the MAC or PHY layer, or we could pass
> undecorated packets, and then use some other out-of-band means
> (socket?) to control attributes in the lower layers.
> 
> Thoughts or comments?  What would you like to see?

Ideally, I'd like to see a physical layer API so I can write my own MAC
layer.  Can GNU Radio handle 802.11 a/b/g?  What I'd like to do is have
a MAC layer smart enough to detect when the MAC protocol it's using
isn't optimal given network conditions, and then switch to a protocol
better suited to the traffic characteristics.  For examle, 802.11 has
DCF and PCF modes.  For smaller networks, DCF (based on CSMA/CA) is
normally fine, but when you reach a certain number of nodes, or start
having nodes that are sending large amounts of data, PCF can be better
suited because of its contention-free period.

I'm not sure how feasible that would be, but I'd like to start by
implementing simple DCF and PCF schemes and eventually work towards an
802.11 implementation.  A fake network device would be nice, though.  If
nothing more, it lets applications take advantage of the radio in a
standard way.
-- 
Rahul Dhar
address@hidden
Actually, my goal is to have a sandwich named after me.

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