Google, Microsoft, Comcast Say Verizon’s New Cellular Tech Could Wreck Wi-Fi • Hacker News Board

Re: Google, Microsoft, Comcast Say Verizon’s New Cellular Tech Could Wreck Wi-Fi

#171

Post by simoncion » Tue, Dec 08, 2015, 6:51 AM UTC

mirimir wrote: post #101

oasisbob wrote: post #86

Earlier quoted context omitted.

Higher powered APs don't help transmissions from the client which face the same interference.

Doh. Thanks. So software tweaks, then. Yes?

I gather that the only currently feasible software tweak you could add to WiFi [0] would be to make it a substantially ruder radio neighbor by failing to wait to transmit until its transmission channel is clear.

In that world, noone wins.

[0] Other, cooler schemes require that WiFi radio manufacturers put more smarts into their radios. There are several 802.11 standards that would make WiFi devices more performant in the face of interference, -probably- remove the hassle of AP channel selection, and distribute relevant metadata about an AP to clients before they connect to aid the human in selection of the proper network and the machines in determining if the client possesses -say- credentials of some kind from a partner network that this WiFi network will honor. The benefit of adding stuff like this is pretty obvious to techies. However, because most computer users are largely non-technical, it's (apparently) impossible to make the business case to increase the unit cost of one's WiFi products by $20 or so to cover the R&D costs. :(

Re: Google, Microsoft, Comcast Say Verizon’s New Cellular Tech Could Wreck Wi-Fi

#172

Post by simoncion » Tue, Dec 08, 2015, 6:54 AM UTC

silverfox17 wrote: post #112

qb45 wrote: post #75

Earlier quoted context omitted.

> Well the good news is that LTE-U appears to be for the 5 GHz band I worry that it could make the 5G band look like 2.4G looks now. I too like the idea of a piece of spectrum used mainly by consumers or small businesses and not saturated by the big commercial gorillas. If today they are desperate enough to consider running their precious services on the wild unregulated bands then sooner or later they will be desper…

Where I live we have 2 WISPs - the 5GHz band already looks like the 2.4 band. This would potentially just wreck internet service for thousands of people.

Are the WISPs attaching WiFi APs to (or near) their antennas to provide service to the surrounding area?

If they aren't, then -AIUI- 5GHz (and 40GHz) gear commonly used by WISPs is highly directional and requires somewhat careful alignment in order to work. (I've heard the term "pencil beam" thrown around to describe the antenna pattern.)

Re: Google, Microsoft, Comcast Say Verizon’s New Cellular Tech Could Wreck Wi-Fi

#173

Post by yuhong » Tue, Dec 08, 2015, 7:49 AM UTC

rupellohn wrote: post #6

Here is the actual study - it is an interesting read: http://apps.fcc.gov/ecfs/document/view?id=60001078145 In a nutshell; the LTE transmission cycles on and off on a regular cadence without sensing if the channel is clear. This tramples over the 802.11 frames and results in higher utilization of the medium than that which is claimed by Qualcomm

I think the worst thing are the 802.11 frame errors that results.

Re: Google, Microsoft, Comcast Say Verizon’s New Cellular Tech Could Wreck Wi-Fi

#174

Post by im2w1l » Tue, Dec 08, 2015, 8:59 AM UTC

saintgimp wrote: post #145

adventured wrote: post #103

Earlier quoted context omitted.

Because the Internet was the first - and so far only - global free or mostly free market that has ever existed. It came of age at a time in which every major economy is highly regulated, rigid and bureaucratic. By design it came into this world with: free speech and expression, the ability to create and start things at will without permission (no little bureaucrat to get approval from first), and had little to no tax…

Um - in this case we're saving the internet (well, really radio spectrum that people use to access the internet) from private corporations, not the government. A totally free market sucks because there will never be a properly-maintained commons. If it weren't for the government, maybe I'd bolt my router to a 10-kilowatt transmitter so I can get my home wifi signal while I'm grocery shopping. So what if it sucks for…

I understand your point in general, but in this case you could probably solve it by building a faraday home, and/or use a frequency that decays rapidly, combined with repeaters around your home to counter your signal suffering decay.

Re: Google, Microsoft, Comcast Say Verizon’s New Cellular Tech Could Wreck Wi-Fi

#175

Post by jrockway » Tue, Dec 08, 2015, 9:32 AM UTC

simoncion wrote: post #170

jrockway wrote: post #157

Earlier quoted context omitted.

Precisely. The big problem with 5GHz's reputation is that most access points, by default, pick channels where only low power is allowed. Lower power than 2.4GHz == lower range than 2.4GHz. Although I believe all channels are high-power channels now (as of late last year or early this year?), switching to one of the old high-power-allowed channels can help. 149 is recommended. I have yet to see any scientific paper th…

> Although I believe all channels are high-power channels now... If they are, my Linux systems aren't yet aware of the change. They make the claim that the only ranges with a 30dBm transmit power are 2402 - 2472MHz and 5735 - 5835MHz. All other WiFi bands are 23dBm. (Though it does seem like the transmit power in the 5.49 - 5.73 GHz range got increased from 17 to 23dBm somewhat recently.) > I have yet to see any scie…

Regarding footnote [2], this is where 5GHz really helps. With 80MHz channels, you'll be using 1/4 the airtime to send the same amount of data.

2.4GHz is to be avoided if at all possible.

Also, measuring SNR is interesting, but you should really run a speed test of some sort. A team I work with wrote this to let access points speedtest clients without any code on the client:

https://gfiber.googlesource.com/vendor/google/platform/+/mas...

(Only really tested with ath9k and ath10k. Could possibly work with other chips.)

Of course, there are many variables on translating link quality to actual throughput. Rate control algorithms are essential, and often wrong. For example, consider sending at 10x the speed and losing 2x the data. Most rate control algorithms will avoid that scenario, even though it's actually faster and conserves valuable airtime.

This is good reading on that subject: https://wireless.wiki.kernel.org/en/developers/documentation...

Re: Google, Microsoft, Comcast Say Verizon’s New Cellular Tech Could Wreck Wi-Fi

#176

Post by msh » Tue, Dec 08, 2015, 10:26 AM UTC

dogma1138 wrote: post #139

mikecb wrote: post #13

That comcast is part of this coalition is hilarious. My apartment building is flooded by xfinitywifi beacons, in addition to each subscribers private SSIDs. Why they insist on turning on this functionality even in urban environments boggles the mind.

Buy RF blocking window film if you are having so many issues. http://www.slt.co/Products/RFShieldingWindowFilm/RFWindowFil... There's also a wallpaper (and even paint) version of this which isn't terrible expensive if you are living in an apartment building with exterior dry walls instead of concrete. This is pretty much the "civilian" version of stuff government agencies use to RF proof undercover sites which could…

But would that not risk breaking your cellular signal?

Re: Google, Microsoft, Comcast Say Verizon’s New Cellular Tech Could Wreck Wi-Fi

#177

Post by datenwolf » Tue, Dec 08, 2015, 10:45 AM UTC

revelation wrote: post #108

jostmey wrote: post #89

So if Wi-Fi performance is hampered then we might have to rely more on cellular data.

That can not happen. Cellular data is not another dumb pipe, it's data transmission grafted with duct tape onto GSM et al., which are ridiculously centralized and proprietary services. There are no open source implementations, no open source hardware, certainly no open source drivers. Even if there were, you would be at the mercy of whoever operates the base station.

http://osmocom.org/

Re: Google, Microsoft, Comcast Say Verizon’s New Cellular Tech Could Wreck Wi-Fi

#178

Post by dogma1138 » Tue, Dec 08, 2015, 1:27 PM UTC

msh wrote: post #176

dogma1138 wrote: post #139

Earlier quoted context omitted.

Buy RF blocking window film if you are having so many issues. http://www.slt.co/Products/RFShieldingWindowFilm/RFWindowFil... There's also a wallpaper (and even paint) version of this which isn't terrible expensive if you are living in an apartment building with exterior dry walls instead of concrete. This is pretty much the "civilian" version of stuff government agencies use to RF proof undercover sites which could…

But would that not risk breaking your cellular signal?

It didn't affect cell reception for me, you should be able to find something that only works on 2.4> and leave lower bands alone.

LTE uses 2.5 but it's not that common 1900-1800 and 800-900 are still the most commonly used cellular bands.

I also plugged only a single window if you check which walls/windows leak the most and plug them it should allow cell reception through.

Re: Google, Microsoft, Comcast Say Verizon’s New Cellular Tech Could Wreck Wi-Fi

#179

Post by simoncion » Tue, Dec 08, 2015, 1:45 PM UTC

jrockway wrote: post #175

simoncion wrote: post #170

Earlier quoted context omitted.

> Although I believe all channels are high-power channels now... If they are, my Linux systems aren't yet aware of the change. They make the claim that the only ranges with a 30dBm transmit power are 2402 - 2472MHz and 5735 - 5835MHz. All other WiFi bands are 23dBm. (Though it does seem like the transmit power in the 5.49 - 5.73 GHz range got increased from 17 to 23dBm somewhat recently.) > I have yet to see any scie…

Regarding footnote [2], this is where 5GHz really helps. With 80MHz channels, you'll be using 1/4 the airtime to send the same amount of data. 2.4GHz is to be avoided if at all possible. Also, measuring SNR is interesting, but you should really run a speed test of some sort. A team I work with wrote this to let access points speedtest clients without any code on the client: https://gfiber.googlesource.com/vendor/goog…

> Also, measuring SNR is interesting, but you should really run a speed test of some sort.

No doubt. Next time I find myself in something similar to my apartment, but in the middle of nowhere so's the three or four-dozen 2.4GHz APs that surround me don't confound the results, I'll do just that. :)

FWIW, the SNR measurements were taken with a UBNT SR-71E (802.11agn ath9k-driven) client that Linux reports as an AR928X.

I'll make a note to look at that wifiblaster program later this week. That could be pretty useful. Unrelated to that, how's the ath10k driver looking? Does it work most of the time for most supported cards these days, or does it still come with a boatload of caveats?

Re: Google, Microsoft, Comcast Say Verizon’s New Cellular Tech Could Wreck Wi-Fi

#180

Post by [deleted] » Tue, Dec 08, 2015, 5:51 PM UTC

gst wrote: post #163

wtallis wrote: post #155

Earlier quoted context omitted.

> " My current Comcast line is so fast that I don't experience any issues due to congestion - so how would I benefit from QoS? " Are you sure you don't have a few hundred milliseconds of bufferbloat in your cable modem, as is the case for almost all modems out there?

No - I'm not. But my connection works well enough and I don't notice any delays on either SSH or VoIP connections. So why should I invest time/energy into changing something that doesn't affect me?

[deleted]