On Mon, 27 Jun 2016, Bob McMahon wrote:
Hi All,
This is a very interesting thread - thanks to all for taking the time to
respond. (Personally, I now have better understanding of the difficulties
associated with a PHY subsystem that supports a wide 1GHz.)
Not to derail the current discussion, but I am curious to ideas on
addressing the overhead associated with media access per collision
avoidance. This overhead seems to be limiting transmits to about 10K per
second (even when a link has no competition for access.)
I'm not sure where you're getting 10K/second from. We do need to limit the amount of data transmitted in one session to give other stations a chance to talk, but if the AP replies immediatly to ack the traffic, and the airwaves are idle, you can transmit again pretty quickly.
people using -ac equipment with a single station are getting 900Mb/sec today.
Is there a way,
maybe using another dedicated radio, to achieve near instantaneous
collision detect (where the CD is driven by the receiver state) such that
mobile devices can sample RF energy to get theses states and state changes
much more quickly?
This gets back to the same problems (hidden transmitter , and the simultanious reception of wildly different signal strengths)
When you are sending, you will hear yourself as a VERY strong signal, trying to hear if someone else is transmitting at the same time is almost impossible (100 ft to 1 ft is 4 orders of magnatude, 1 ft to 1 inch is another 2 orders of magnatude)
And it's very possible that the station that you are colliding with isn't one you can hear at all.
Any AP is going to have a better antenna than any phone. (sometimes several orders of magnatude better), so even if you were located at the same place as the AP, the AP is going to hear signals that you don't.
Then consider the case where you and the other station are on opposite sides of the AP at max range.
and then add cases where there is a wall between you and the other station, but the AP can hear both of you.
David Lang