[mc1322x] 6LowPAN data payload

[Mariano Alvira]

On Wed, Jul 14, 2010 at 04:25:49PM -0400, Jon Smirl wrote:
> 
> While it is all fresh in your mind you might want to look at energy
> detect and clear channel assessment.

Ha! I think that code is seared into my brain. I wish it would
un-fresh! I have nightmares about the maca. 

(semi)jokes aside --- I'm not sure either of those are too "hard". The
bigger problem is making sure they work. For CCA, I think the thing to
do is wire two econotags together. Then the one doing the CCA knows
when the other is transmitting and I can have a good verifiable test
that it works.

ED might be a little bit more annoying since it looks like it involves
programming undocumented gains and thresholds. Luckily it looks like
the r0 datasheet has some of that info. 

ED similarly has a verification problem. I need to look at what it's
suppose to report and what the spec says it's suppose to report. Then
I plan to use my VNA to send various levels of "energy" which I'll
"detect"... That actually sounds kind of fun.

Of course every little poke at the MACA turns into a multi-day fiasco
--- so I have to plan accordingly.

> Are there other interesting MACA functions?

Yes --- there is all the hardware level 802.15.4 stuff that Contiki
does anyway (or doesn't use). Auto-ACKing for instance. And all of the
filtering (beacons, pan id, mac id, etc..). There is also hardware to
help with the synchronization stuff a beaconed 802.15.4 network can
use (slotted TX/RX etc). So maybe the bullet list is:

 + CCA
 + ED
 + hardware filtering
 + beaconing/syncronization/slotted-modes.

-Mar.