[Battlemesh] IEEE magazine on FCC lockdown

[Jonathan Morton]

> On 20 Apr, 2016, at 18:44, Simon Wunderlich <sw at simonwunderlich.de> wrote:
> 
> For DFS, we need to detect radars (that's layer 1). But once it was detected, 
> we need to send a channel switch announcement (layer 2) and make stations or 
> other mesh participants move to a new channel together with us.
> 
> That's exactly the part which wasn't implemented or disabled in the drivers 
> (by users, firmwares, etc), which brought up this problem.

I immediately thought of a workaround for this.

When Layer 1 detects a radar, it should reject all further transmission requests from Layer 2 on that frequency, *unless* they are tagged with a DFS-override code.  Additionally, transmissions using the DFS-override code are strictly limited in duration to that necessary to get those administrative packets out.

This prevents Layer 2 from blithely ignoring DFS, while maintaining basic layer separation.

 - Jonathan Morton