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A deep dive into why Wi-Fi kind of sucks

arstechnica.com

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Re: A deep dive into why Wi-Fi kind of sucks

#161

Post by krallja »

bcarlton0 wrote: post #66
Klathmon wrote: post #42

Earlier quoted context omitted.

So on that note, do you have any brands/manufacturers/chipsets that you see as particularly good in terms of being a client? Its always a gamble when I get a new phone/laptop/device if it will work with the multi-AP setup I have in my house, and I'm really tired of getting something and bringing it home only to find it hangs on to the furthest AP for dear life.

Ubiquiti UniFi AC or UniFi AC-LR. I'm not the poster above you were asking. Never need rebooting. Present a single AP name for multiple devices and both 2.4 and 5.x GHz. Reasonable price for home use. Based on personal experience in a large house. grk, roaming works just fine.

Klathmon was asking about clients, not APs.

Re: A deep dive into why Wi-Fi kind of sucks

#162

Post by Spooky23 »

willidiots wrote: post #9

I build public Wi-Fi networks, you've probably used one of them. AMA if you have Wi-Fi questions. To say it "sucks" is a bit harsh. It's delivering multiple hundreds of Mbps to you via an unlicensed contention-based medium. The air interface is like sending packets over a noisy Ethernet hub; it's impressive it works as well as it does. That said, this article's a good primer on some of the protocol's fundamental chal…

Seriously. Wifi is a miracle product.

Even if you forget the ubiquity of it... it saves ridiculous amounts of money. 15 years ago, we'd spend like $50k to wire up new office space for 100-150 people. Now... maybe $5k with cable pull.

Re: A deep dive into why Wi-Fi kind of sucks

#163

Post by [deleted] »

willidiots wrote: post #9

I build public Wi-Fi networks, you've probably used one of them. AMA if you have Wi-Fi questions. To say it "sucks" is a bit harsh. It's delivering multiple hundreds of Mbps to you via an unlicensed contention-based medium. The air interface is like sending packets over a noisy Ethernet hub; it's impressive it works as well as it does. That said, this article's a good primer on some of the protocol's fundamental chal…

[deleted]

Re: A deep dive into why Wi-Fi kind of sucks

#164

Post by Dylan16807 »

extra88 wrote: post #60
Klathmon wrote: post #44

Earlier quoted context omitted.

I used to live about 1/4 mile away from any other houses, and I never got why people always complained about wifi. In my experience it always worked well, was fairly fullproof, and had fast enough speeds that it was never an issue. 2 years ago I moved into a condo that has 25 wifi APs within range of me right now. Now I get it. Getting one of the high-end tri-band routers as you said did help, but it's still a diffic…

I never heard of a tri-band router before. It's a misnomer because there is no third band, it just means it can handle 2.4GHz but will use two channels of 5GHz at once. There have been other routers in the past that used more than one channel but it sounds very selfish to use in a dense apartment/condo living situation.

It's worse than that. There is a third band, 802.11ad running at 60GHz. But as you say "tri-band" actually means tri-channel.

Re: A deep dive into why Wi-Fi kind of sucks

#165

Post by mhandley »

matwood wrote: post #146

I suggest reading up on how WIFI works and some of the problems like hidden nodes [1]. Sometimes I'm amazed WIFI works at all. [1] https://en.wikipedia.org/wiki/Hidden_node_problem

The classical hidden terminal problem, where two clients of the same AP can't receive each other and so collide when they transmit, isn't such a big deal with WiFi. First, there are, by definition, no hidden terminals for the downlink (and most traffic is downstream), or the clients couldn't associate with the AP. Second, although two clients can't receive each other's transmissions, if they're associated with the same AP they can usually hear each other well enough for carrier sense to work.

The usual problem these days is too many overlapping networks. Different APs on the same channel will not only defer to each other when they can hear each other, but also because the AP tends to use a shorter contention window than clients, when they do transmit, they still collide with each other with moderately high probability. Worse, modern 802.11n and 802.11ac only get good performance by forming aggregates of many packets (up to 64KB in 802.11n, more in ac) to reduce the overhead of medium acquisition. Often they don't use RTS/CTS because this reduces performance in benchmarks. When such aggregates collide you lose the whole aggregate, not just one packet.

Re: A deep dive into why Wi-Fi kind of sucks

#166

Post by krallja »

epmaybe wrote: post #149
Groxx wrote: post #147

Earlier quoted context omitted.

Any idea why we do not have public, encrypted wifi? Seems like it should be easy / trivial to fix, and protects people from passive listeners.

Not sure what you mean by this. Https exists, no?

HTTP is not the only traffic on a network. DNS is rarely encrypted, and many email providers use STARTTLS, which starts unencrypted.

Re: A deep dive into why Wi-Fi kind of sucks

#167

Post by Eiriksmal »

krallja wrote: post #159
Eiriksmal wrote: post #155

Earlier quoted context omitted.

Wow, that article taught me that our office is probably using the wrong setup for optimal VoIP performance. When I started, I bought us an Asus RT-N66U to replace the ancient 802.11g router that was powering the 5 computers, 4 smartphones, 3 ethernet VoIP phones and 1 printer. Fast forward two years and now we have 12 computers on wifi using soft phones, 3 engineering rigs on ethernet, 11 smart phones, and that lonel…

You can put the twin APs on different channels, and the two collision domains shouldn't overlap.

So he's specifically referring to collision on the same channel, not that a device connected to Router A on 2.4 channels 1->4, but can also see Router B on channels 10->13 has to wait to transmit data back to Router A.

Re: A deep dive into why Wi-Fi kind of sucks

#168

Post by Dylan16807 »

coin wrote: post #109
ShinyCyril wrote: post #108

Earlier quoted context omitted.

Do you really think the person you are replying to doesn't know that already? I think you can take it as given that most people here know the difference between MHz and mHz and are perfectly capable of realising it is a typo.

I wouldn't be so sure. You can go pretty far without knowing what a MHz really means. Edit: I've it megahertz written more as mhz than MHZ.

If someone doesn't know what it stands for, that's also not a problem. You would have to have an extremely specific partial understanding to both notice the capitalization difference and not realize it's the same thing.

Re: A deep dive into why Wi-Fi kind of sucks

#170

Post by easytiger »

goodcanadian wrote: post #70
koolba wrote: post #14

Earlier quoted context omitted.

Which router do you recommend? Is the 5G band consistently worse than the default (i.e. constant connection drops) or is that just my experience?

Physics is the issue here. The 5GHz band is going to be better if you are in the same room as the AP. However, it does not penetrate walls as well, so depending on your set up (and the construction of your walls), that might explain your experience.

In two houses on two routers I've had horrendous experience with 5GHz.
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