I am glad, incidentally, that for the first time, this wg is considering some of the problems wifi has, and growing towards understanding them in more detail. I have long been working on finding answers to these deep, underlying problems - after first identifying some the major ones:
https://www.youtube.com/watch?v=Wksh2DPHCDI&feature=youtu.be and proposing some solutions to the IEEE that still worked inside the standard (well, obsoleting part of 802.11e entirely) http://snapon.lab.bufferbloat.net/~d/ieee802.11-sept-17-2014/11-14-1265-00-0wng-More-on-Bufferbloat.pdf and also proposing some deep changes for 802.11ax (the successor to ac). Work on getting some of that stuff done is proceeding - unfunded, by volunteers that care, in their spare time... (one major set of needed patches: "minstrel-blues" - coupled power and rate control - is out for review on the linux-wireless mailing list and it could used an acked-by because it is great and desperately needed. You don't need to transmit at the highest possible rate when you are right next to the AP, and vice versa) Finally, a few weeks ago, I convinced a major wifi testing house to actually start poking at one subset of the problem, which is multiple stations attempting to transmit at the same time. This test uses a single TCP flow each, 1 up, 1 down, and measures the latency. http://www.candelatech.com/downloads/rtt_fair4be-comparison-box-plot.png This is on the latest and "best" 802.11ac hardware on the retail market, transmitting at the highest possible rate, to 4 stations, under lab conditions. Under load, you presently observe latencies of 50-1000ms, and jitter, same. They only achieved ~ 1/3 the rate of the base mac capability. They haven't tried lower rates, or added interference, nor mixed in multicast, nor tried WDS, or 802.11s, or added stations - any one of which can mess things up by another order or two or *more* of magnitude, I am awaiting further results from them, testing lower rates in particular. But I do hope that they eventually manage to duplicate the kinds of results I have obtained all over the world in conference centers, hotels, and apartment buildings, where the typical latencies I observe can be in the 3-6 second range, and bandwidth, below a few dozen k, at best. This sort of result should be concerning to the people that would like to bridge everything, use range extenders, transmit any multicast at all (and add in new forms of multicast, like nd/hnetd/babel/etc), or have hope that wifi can continue to work at all - in the face of adding lots and lots more (IoT) wifi clients - without some major work on how our APs and client chipsets work at a deep level. And thus, this is why I am not paying a whole lot of attention to the ietf anymore, and sinking more of my energies into finding ways to preserve and repair one of the coolest, most free-ing internet technologies that has has ever existed. And it is also sort of why I am running ethernet or homeplugs everywhere I must. _______________________________________________ homenet mailing list [email protected] https://www.ietf.org/mailman/listinfo/homenet
