[LEDE-DEV] portal wifi router

[David Lang]

 On Thu, 23 Jun 2016 14:55:05 -0400, Michael Richardson wrote:
> Bill Moffitt <bmoffitt at ayrstone.com> wrote:
>     > I love the idea of meshing WiFi systems adapting their channel 
> settings
>     > around local interference... so the Plume in my house detects 
> that my
>     > next door neighbor's Portal is interfering, so it changes its
>     > channel. However, the Plume in my garage is much closer to the 
> neighbor
>     > behind me than the Plume in my house, and changes the channel 
> to avoid
>     > them. This then interferes with the neighbor's Portal, which 
> changes
>     > its channel to avoid my interference, which then interferes 
> with the
>     > neighbor behind me, who changes channel to avoid that 
> interference...
>
> This is the map colouring problem as you point out:
>
>     > P.S. for the mathematically inclined, note the discrepancy 
> between the
>     > 3 distinct channels in the 2.4 GHz. band and the application of 
> the
>     > 4-color theorem to channel selection. Sucks...
>
> Am I wrong in thinking that if you can lower your Tx power that you 
> can bleed
> less into adjacent channels?

 well, lowering TX power reduce your impact on everything, including 
 adjacent channels, but not enough.

 things can be done with good antenna design, but you would need to do 
 the same thing on both ends, and you still have a problem that your 
 transmitter and receiver are so close to each other that it's really 
 hard to isolate them.

 unfocused power drops off at the cube of the distance, so things a few 
 feet apart have a tremendous advantage to the same things within a 
 couple inches of each other (completely ignoring signals propagating 
 over power/ground busses and things like that)

 David Lang