More Cellphone Data Use Is Negatively Affecting Wi-Fi Performance, Study Finds (uchicago.edu) 46
An anonymous reader shares the findings of a new study from the University of Chicago. From a report: If service becomes slow when you're trying to send a quick email on your smartphone, you might scroll through your network options and discover how many Wi-Fi networks there are. In fact, this plethora of options is itself the problem. These networks are in competition with one another, limiting the speed at which each can operate. University of Chicago researchers have demonstrated how this increased network competition could negatively impact internet service for everyday users.
When a cellular provider, such as T-Mobile or AT&T, licenses a spectrum band from the FCC, they reserve its exclusive use. As a result, networks operating on licensed bands experience little interference. This allows providers to establish fast and reliable service, but it comes at a cost. To improve bandwidth [to accommodate] more users] without breaking the bank, these providers have begun to also use the unlicensed spectrum via cellular networks using a mode called licensed assisted access (LAA), which operates on the same bands used for Wi-Fi. [The researchers] set out to examine how this shared use of the unlicensed spectrum, called coexistence, impacted both Wi-Fi and cellular users.
"We actually found an LAA station located on the UChicago campus, on a pole in front of the bookstore, and in this outside space campus Wi-Fi is also in use," [Monisha Ghosh, associate member in the Department of Computer Science at the University of Chicago and research professor in the Pritzker School of Molecular Engineering] said. "That provided an experimental platform in our backyard, so we started taking measurements." [...] By accessing multiple networks simultaneously, the group found that competition decreased performance -- reducing the amount of data transmitted, the speed of transmission, and the signal quality. This competition was particularly detrimental to Wi-Fi. When LAA was also in active use, data transmitted by Wi-Fi users decreased up to 97%. Conversely, LAA data only exhibited a 35% decrease when Wi-FI was also in use. Ghosh explained that the incompatibility between Wi-Fi and LAA owes in part to the different protocols each employs to deal with heavy internet traffic. The researchers presented their findings in a paper via arXiv.
When a cellular provider, such as T-Mobile or AT&T, licenses a spectrum band from the FCC, they reserve its exclusive use. As a result, networks operating on licensed bands experience little interference. This allows providers to establish fast and reliable service, but it comes at a cost. To improve bandwidth [to accommodate] more users] without breaking the bank, these providers have begun to also use the unlicensed spectrum via cellular networks using a mode called licensed assisted access (LAA), which operates on the same bands used for Wi-Fi. [The researchers] set out to examine how this shared use of the unlicensed spectrum, called coexistence, impacted both Wi-Fi and cellular users.
"We actually found an LAA station located on the UChicago campus, on a pole in front of the bookstore, and in this outside space campus Wi-Fi is also in use," [Monisha Ghosh, associate member in the Department of Computer Science at the University of Chicago and research professor in the Pritzker School of Molecular Engineering] said. "That provided an experimental platform in our backyard, so we started taking measurements." [...] By accessing multiple networks simultaneously, the group found that competition decreased performance -- reducing the amount of data transmitted, the speed of transmission, and the signal quality. This competition was particularly detrimental to Wi-Fi. When LAA was also in active use, data transmitted by Wi-Fi users decreased up to 97%. Conversely, LAA data only exhibited a 35% decrease when Wi-FI was also in use. Ghosh explained that the incompatibility between Wi-Fi and LAA owes in part to the different protocols each employs to deal with heavy internet traffic. The researchers presented their findings in a paper via arXiv.
News at 11 (Score:4, Insightful)
So, the more people using WiFi & Cellular congests the available spectrum, say it ain't so!!
LAA is actually news for me! (Score:5, Insightful)
LAA (LTE in unlicensed spectrum) is news for me at least (I live in the UK and we don't seem to have it), and it is outrageous. I am reading now how Qualcomm made it a big deal to prove to the FCC that carriers using LAA will not interfere with WiFi signals, and this study shows the exact opposite.
It seems that carriers in some countries, including the US, are trying to expand their coverage without paying for more spectrum, by using the 5GHz frequency, and so far they are allowed to do it, to the detriment - as this paper claims - of WiFi.
From the summary I thought this is a non-issue, multiple competing WiFi networks slow things down etc, until I googled what LAA is...
Re: LAA is actually news for me! (Score:4, Insightful)
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or are the carriers circumventing limits and getting special permission to use 5ghz at insanely high gains?
The carriers are supposed to follow Part15 that gives certain mW power limits just like anybody else. It's possible, of course, that they or their equip. manufacturer choose to ignore the rules, or they may be in a way skirting the power limits of the 5GHz band.... I guess, for example with certain heights and antenna configurations: you can make your signal reach farther and with more power potent
Re: LAA is actually news for me! (Score:5, Insightful)
Re:LAA is actually news for me! (Score:5, Interesting)
The issues is the carriers purposefully degrading "free to use" spectrum so people are more willing, if not driven to use the spectrum they need to pay for.
Even the Obama era net neutrality regulations had carve-outs for cell bandwidth. Anything the carriers could do to push people away from wired and broadcast communications (TV & radio) they've done purely to increase their billing. It's a despicable rent-seeking practice and they should be punished for it.
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> people are more willing, if not driven to use the spectrum they need to pay for
And, just to rub a little more salt into the wound, they'll be paying to use the same spectrum that they were using for free* in the first place.
* If not paying for twice, that is. Campus Wifi, for instance, they're already paying for with their uni fees.
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Need Dedicated WiFi Bands (Score:4, Insightful)
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So, the more people using WiFi & Cellular congests the available spectrum, say it ain't so!!
If you read TFS you'd understand why your comment isn't the point here. Try again and focus on the last two sentences.
So cellular providers, such as T-Mobile or AT& (Score:2)
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It's not illegal use. Everyone (you, them, me) is allowed to use unlicensed spectrum wireless frequencies like those used by Wifi (near 2.4Ghz and 5Ghz, 6Ghz, etc)
Re:So cellular providers, such as T-Mobile or AT&a (Score:4)
You are allowed to use that spectrum *IF* you follow the rules. It is not a free-for-all.
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Different set of people have "discovered" this.
Now that I have unlimited cellular data, I rarely connect to any wifi network unless I have no signal or I am at home and need access to my network. Sometimes my cellular link at only 4g will run faster then my wifi but my hardwired computers don't see any dip in speed at all. It's probably because there are nearly 15+ wifi networks within range of me. Possibly more.
Definitely something that most techies would call obvious and hopefully common knowledge.
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Definitely something that most techies would call obvious and hopefully common knowledge.
Indeed. Fascinating I get down-voted for stating this though. Apparently some people do not care about realities and just want to demand things to be working well.
This used to be illiegal AFAIK (Score:3)
I was working for an ISP back in the day and the one carriers was shooting a 20 mile link to another cell tower to haul their excess traffic. This was right in the way of the unlicensed bands and interfering with the bands the ISP used. I was told this was illegal (don't know), but in my opinion a carrier that has the ability to expand their network with physical lines like fiber or copper for a data line should be required to do that and not use public bands.
Re:This used to be illiegal AFAIK (Score:5, Informative)
This takes me back (Score:4, Insightful)
To PAX 2008 when Nintendo DS ownership hit critical mass and completely overloaded the wireless space with people trying to network games.
Who knew the same principle applies now?
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If you think that's the issue then maybe you should read the paper before posting. The fact that they are using additional wireless space is only a tiny part of why LAA operating in the wireless band is bad.
Who knew the same principle applies now?
In the future, anytime you think someone put effort into studying "the obvious" ask yourself if you actually understood what it is they said. Hint: your DS example is not the issue here.
Since I'm home 99% of the time (Score:2)
I only use WIFI for my phone's data. In 15 or so months. I haven't used pretty much any data.
I only get 1 free Gb a month, and I've used 256Kb this month, when I wasn't home, or the power was out and I wanted to check outage websites.
Of course, I'm paying $14 a month for my "unlimited" text and phone calls. If I could add some solar to my power I'd probably be paying negative amounts.
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Did you switch to this plan prior to covid or was this something you did because why waste money on a data plan if you can't go anywhere anyway?
While no one needs a smart phone with data, it certainly comes in handy when you do need it or otherwise want to find something out quickly.
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Well, it's expensive. Why spend another $10-50 more a month for a data plan you won't actually use? I tried to get my first smartphone to not have a data plan and it wasn't allowed, so I had the minimum of 300mb/month which was more than I used. And even if you don't use the data plan, if it's turn on it WILL use some data anyway in the background. Also I find that the battery drain is much more pronounced when cellular is on even if it's also on wifi.
When I *do* want cellular, I can turn it on and use
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I have an iphone, and it has a bizarre feature. I use wifi all the time, cellular is extremely rare and for those times when I really need to do something on the internet while not at home or at work. It saves battery life tremendously. But... if I get voice mail the iphone will not tell me this unless I turn on cellular data. Once I do so it notifies about the voice mails almost immediately when it gets a connection and then I can turn it off and listen to the voice mail normally using wifi. This beh
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Do you have Wi-Fi Calling enabled?
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It's off.
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I usually have it off as well (I've had sporadic call problems with it on). I wonder if that's the difference? I bet if you kept Wi-Fi calling on, and put on airplane model (cell service off), voicemail would work. No idea!
Re: Since I'm home 99% of the time (Score:2)
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I would expect the same behavior on Android - maybe you switched carriers at the same time. Visual voicemail is hosted on a carrier server and they probably have it firewalled off from the public Internet. So it would only work through the carrier network.
For fun, I looked up the specs:
https://www.gsma.com/newsroom/... [gsma.com]
It's a funny, funny read. Visual voicemail operates on SMS and IMAP4. Not kidding. The carrier texts your phone that there's a new message and includes the IMAP username and password in t
I just got a 5G phone from T-Mobile (Score:2)
Damn 5G kids, get off my Wlan ! (Score:2)
Sorry.
no doubt about that (Score:2)
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I used to try to do this. Now, I have a bunch of IoT crap that is 2.5GHz-only. What irks me about this isn’t the IoT stuff— I get why they do it— but the lack of extremely low-power, modern 2.5GHz access points, preferrably that are centrally manageable by something like Unifi.
Of course (Score:2)
these providers have begun to also use the unlicensed spectrum via cellular networks using a mode called licensed assisted access (LAA), which operates on the same bands used for Wi-Fi.
If I could mess up my competition as well as get a free ride on their systems, I would too.
I thought 5G was supposed to be really great. And they still need to steal bandwidth from other people?
So WiFi network competition slows you down? (Score:2)
If competition goes away, maybe your text message will get through a bit quicker. Of course, you can bet this same lack of competition is going to result in a serious raid on your wallet. Corporations are funny like that.
Who needs wifi (Score:2, Troll)
Everyone should switch to 5G, and no I am not saying phone company. Instead of a WiFi router at home you can have a lower energy LTE router instead. It will work better and more seamlessly.
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WTF?! Some of us want/need to control our own networks rather than shove everything into the cloud.
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What does a home ultra-low-power 5G base station have to do with cloud? It's the same thing as having a WiFi router except it uses LTE. Nothing changes other than you'd be using a different modem and frequencies.
Any special hardware on phones required? (Score:1)
I wonder if there is any special chips / antenna needed on mobile devices for this to work.
Or does it just use the wifi hardware capabilities but with a different protocol?
And since this is in a public unlicensed band, can someone create something that targets such access points and not get into trouble for it? Maybe send out some weird data to such access points to make them lag / crash and at same time produce minimal effect on regular wifi users?
Fight back? (Score:2)