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

[Jonathan Morton <chromatix99@gmail.com>]

> On 27 Aug, 2018, at 10:06 am, Bob McMahon <bob.mcmahon@broadcom.com> wrote:
> 
> How can a centralized device predict the many "end stations'" network demand in its time scheduling?

DOCSIS does it by initially giving stations a tiny window into which to send requests for time, which are granted by the head-end.  This introduces some latency.  Further requests for time can be appended to a real transmission, which helps efficiency slightly.

Developing from that model, an AP might initially divide time evenly between stations, allowing them to send single large packets or several small packets without an explicit request for time - this is good for latency.  Along with that packet, the station could indicate to the AP that it has a queue of packets waiting, and the AP would take that into account when producing its next schedule.  It would also take into account its own queue.

It may be possible to combine TDM with orthogonal coding.  Here the AP monitors the received signal strength of its stations, and instructs them to change power so as to minimise the difference between them.  This maximises the SNR for each, should two transmit simultaneously.  The tradeoff, of course, is that orthogonal coding permits a reduction in waiting to transmit, but requires a reduction in data rate during the transmission.  I'm sure other people have better data on that than I do.

 - Jonathan Morton