Re: [Bloat] [Make-wifi-fast] [Cerowrt-devel] closing up my make-wifi-fast lab

[Jonathan Morton <chromatix99@gmail.com>]

> On 27 Aug, 2018, at 10:11 pm, Bob McMahon <bob.mcmahon@broadcom.com> wrote:
> 
> I guess my question is can a WiFi transmitting device rely on primarily energy detect and mostly ignore the EDCA probability game and rather search for (or predict) unused spectrum per a time interval such that its digital signal has enough power per its observed SNR?   Then detect "collisions" (or, "superposition cases" per the RX not having sufficient SINR) via inserting silent gaps in its TX used to sample ED, i.e. run energy detect throughout the entire transmission?  Or better, no silent gaps, rather detect if there is superimposed energy on it's own TX and predict a collision (i.e. RX probably couldn't decode its signal) occurred?  If doable, this seems simpler than having to realize centralized (or even distributed) media access algorithms a la, TDM, EDCA with ED, token buses, token rings, etc. and not require media access coordination by things like APs.

The software might be simpler, but the hardware would need to be overspecified to the point of making it unreasonably expensive for consumer devices.

Radio hardware generally has a significant TX/RX turnaround time, required for the RX deafening circuits to disengage.  Without those deafening circuits, the receivers would be damaged by the comparatively vast TX power in the antenna.

So in practice, it's easier to measure SNR at the receiver, or indirectly by observing packet loss by dint of missing acknowledgements returned to the transmitter.

 - Jonathan Morton