5 ms·

> What's wrong with expecting WIFI to work well enough to enjoy low latency high definition/4k content? You can totally do that in rural areas. I'm talking at

> What's wrong with expecting WIFI to work well enough to enjoy low latency high definition/4k content? You can totally do that in rural areas. I'm talking at least 1/4 mile separation between houses. If you're not in that kind of area and you still expect it, it's because you don't understand the physics. I don't mean that as an insult, just a statement of fact. I went to school for electrical engineering and that statement you made above is laughable for anyone who knows the trade. To me, a similar statement might be "Why can't I have a car that makes 1000 HP, gets 100 MPG and costs $10k?" Yes someday that might be a reality but with the tech we have now, it's definitely not. Bandwidth over the air is fixed and it's split between everyone who is within "earshot" and similar to how it eventually gets impossible to hear anyone at a party once the room is packed and everyone is talking, so it goes with wireless. There's just not enough spectrum to go around. That's why people use wires; every wire has (roughly) a whole spectrum all to itself. Pull 100 wires? Get 100x bandwidth. Put up 100 wireless transmitters? Get 1/100 the bandwidth on each one. The math there heavily, heavily favors wires. Ethernet, coax, fiber, whatever. If you make a new signal propagation domain you can use as much of it as it'll allow you. If you use the big signal propagation domain that everyone has access to, prepare to share.

ryao 10y ago
To play devil'a advocate, a Ruckus Zoneflex R710 ought to work well in such places. Also, I have gotten wifi working well in non-rural areas using Ubiquiti Unifi AC Lite APs. In suburban New York, a couple of them blanket my home. In my grandmother's Shanghai apartment in a building that is a mix of concrete and plaster, just 1 is sufficient (although for a much smaller volume), despite dozens of nearby APs. Admittedly, I moved to 5GHz there because I was literally the only one using it, but 2.4GHz had worked fine when I tried it. Peak throughout is higher on 5GHz due to higher channel widths though.
- msandford 10y ago
  I might make an analogy: "I use a dog whistle and no matter how loud people are talking, my dog always hears it" OK, now take your dog to a place full of dogs and other dog whistles. See how well it works. Once the spectrum gets noisy, interference happens. Just because you found a quiet spot in the spectrum doesn't mean that spectrum sharing isn't a physical reality anymore. It just means you found some to keep all to yourself! Until someone else starts using 5GHz too.
  - ryao 10y ago
    I said that I was able to use 2.4GHz reliably despite it being crowded. I only switched to 5GHz because I noticed no one was using it and I saw higher bandwidth on it from 5GHz 802.11ac supporting higher channel widths than 2.4GHz 802.11n supports. In fairness, I had made tweaks to iwlwifi's kernel module options in order to have usable wifi on my laptop. Until a year ago, I was accustomed to have a hellish experience in congested areas until I turned off Bluetooth coexistence support in the iwlwifi driver. That feature would almost always cause severe packet loss on my T520 in crowded environments even when there did not appear to be any Bluetooth traffic. Anyway, it is possible to get wifi working well for certain workloads in crowded environments. Making it work well in general might require better drivers and better equipment than one might have at first though. For example, I understand that ath9k was a disaster when it was first made, but it is fairly decent now. I ran an AP off an ath9k USB wifi dongle in China at one point and it worked well too. I doubt that would have worked as well with drivers from 5 years ago. Also, from what I understand, a used Ruckus Zoneflex 7982 off eBay ought to be able to handle just about any environment fairly well. Their proprietary beam forming hardware is special because it attenuates signals coming from other directions than that of the client. The only exception from what I have read is when other wifi equipment is right next to it (e.g. practically touching). Some review of it said that it failed to work until they moved other equipment away after consulting Ruckus. I cannot find a link to it though. I placed an order with an eBay merchant that I expect to receive soon. $90 per used Zoneflex 7982 (that had a $1099 MSRP when new) is a bargain considering that these still provide some of the best wifi in the world. There are reports of these getting good throughout through multiple concrete walls: http://www.cio.com/article/2388827/wireless-networking/review--ruckus-wi-fi-access-points-for-your-small-business.html http://www.cio.com/article/2388827/wireless-networking/revie... A newer version of the midrange model in their product line (that has inferior radio specifications to the top end model) was able to give a cell phone decent throughput from 225 yards away when the (omnidirectional) AP was in doors: http://www.evdoinfo.com/content/view/5077/64/ http://www.evdoinfo.com/content/view/5077/64/ As far as I know, the only better access points are the newer Ruckus models that replaced it. I am really excited to be getting one later this week. :)
    - robotresearcher 10y ago
derefr 10y ago
Random thought: is there a reason we couldn't construct apartment buildings such that each tennant had a Faraday mesh embedded in their shared walls, but not in exterior-facing walls? It would do strange things to cellular and broadcast radio, but it wouldn't destroy them, I think.
- colanderman 10y ago
  IANAP but I would think such a cage would cause WiFi to reflect internally, causing as much if not more trouble than noisy neighbors. The "real" solution is for people in dense apartment buildings to just turn their damn Tx power down, but that's a prisoner's dilemma if I've ever seen one.
  - PaulHoule 10y ago
    Actually WiFi was designed from the very beginning to do well despite reflections. My thesis advisor knew somebody who was applying ideas from "quantum chaos" to make WiFi robust to various environments at Bell Labs, back in the 1990s, before Carly Fiorina bankrupted Lucent.
  - derefr 10y ago
    It's a prisoner's dilemma in the case where everyone controls their own wireless APs, sure. In the case where the building is served by one major ISP, and they provide combination gateway+APs, I could see the ISP deciding to "solve" the problem by turning the whole building into one AP mesh (with only one AP actually active per unit sphere) where each client gets a VLAN with tagged QoSing over the last-mile "backplane" back to their own gateway. Though, if you're going that far, you may as well just call yourself a WiMAX provider and tell people their gateways are just extension picocells for the network, rather than end-user equipment. Which is basically what you get already from the ISPs that offer "public wi-fi for customers at our hotspots" (i.e. broadcast by all APs on our business plan), except that said wi-fi would be the only product, and would be served by residential gateways as well.
  - korethr 10y ago
    I actually tried to approach this problem in my own apartment complex. The effort died almost immediately. Very few consumer wireless access points even expose Tx power as a configuration parameter at all, even buried in an "Advanced Settings" section somewhere. You're lucky if they even expose channel selection at all. So with the craptastic firemware of most consumer wifi APs, the AP hops on channels 1, 6 or 11, and stays there, screaming at full power. And the consumer, even if they know enough about radio to realize such is suboptimal, can't do anything about it without changing the firmware or buying a more expensive device.
drcongo 10y ago
I live in London (my neighbours are a LOT closer than 1/4 mile) with a shitload of devices on my WiFi and I can still happily stream 4K TV while my my entire family uses iPads or laptops. Am I breaking the laws of physics?
- wang_li 10y ago
  >Am I breaking the laws of physics? No, you're just using subjective feelings rather than objective measurements. 4K doesn't specify a particular bit rate. If there is going to be a productive discussion, it needs to be acknowledged that there is a huge difference between streaming 1080p and Bluray 1080p.
  - drcongo 10y ago
    Why would anyone stream a Bluray?
    - wang_li 10y ago
      No one would want to stream a Bluray. The point was to highlight that there are very different things that are still described by "1080p" and what is more important is the bit rate and codec rather than the common 4K, 1080p, 720p, or even "HD video" names.
      - drcongo 10y ago
        I don't know why you're even talking about 1080p, though I think I vaguely get what you're trying to say.

ryao 10y ago

To play devil'a advocate, a Ruckus Zoneflex R710 ought to work well in such places. Also, I have gotten wifi working well in non-rural areas using Ubiquiti Unifi AC Lite APs. In suburban New York, a couple of them blanket my home. In my grandmother's Shanghai apartment in a building that is a mix of concrete and plaster, just 1 is sufficient (although for a much smaller volume), despite dozens of nearby APs. Admittedly, I moved to 5GHz there because I was literally the only one using it, but 2.4GHz had worked fine when I tried it. Peak throughout is higher on 5GHz due to higher channel widths though.

msandford 10y ago
I might make an analogy: "I use a dog whistle and no matter how loud people are talking, my dog always hears it" OK, now take your dog to a place full of dogs and other dog whistles. See how well it works. Once the spectrum gets noisy, interference happens. Just because you found a quiet spot in the spectrum doesn't mean that spectrum sharing isn't a physical reality anymore. It just means you found some to keep all to yourself! Until someone else starts using 5GHz too.
- ryao 10y ago
  I said that I was able to use 2.4GHz reliably despite it being crowded. I only switched to 5GHz because I noticed no one was using it and I saw higher bandwidth on it from 5GHz 802.11ac supporting higher channel widths than 2.4GHz 802.11n supports. In fairness, I had made tweaks to iwlwifi's kernel module options in order to have usable wifi on my laptop. Until a year ago, I was accustomed to have a hellish experience in congested areas until I turned off Bluetooth coexistence support in the iwlwifi driver. That feature would almost always cause severe packet loss on my T520 in crowded environments even when there did not appear to be any Bluetooth traffic. Anyway, it is possible to get wifi working well for certain workloads in crowded environments. Making it work well in general might require better drivers and better equipment than one might have at first though. For example, I understand that ath9k was a disaster when it was first made, but it is fairly decent now. I ran an AP off an ath9k USB wifi dongle in China at one point and it worked well too. I doubt that would have worked as well with drivers from 5 years ago. Also, from what I understand, a used Ruckus Zoneflex 7982 off eBay ought to be able to handle just about any environment fairly well. Their proprietary beam forming hardware is special because it attenuates signals coming from other directions than that of the client. The only exception from what I have read is when other wifi equipment is right next to it (e.g. practically touching). Some review of it said that it failed to work until they moved other equipment away after consulting Ruckus. I cannot find a link to it though. I placed an order with an eBay merchant that I expect to receive soon. $90 per used Zoneflex 7982 (that had a $1099 MSRP when new) is a bargain considering that these still provide some of the best wifi in the world. There are reports of these getting good throughout through multiple concrete walls: http://www.cio.com/article/2388827/wireless-networking/review--ruckus-wi-fi-access-points-for-your-small-business.html http://www.cio.com/article/2388827/wireless-networking/revie... A newer version of the midrange model in their product line (that has inferior radio specifications to the top end model) was able to give a cell phone decent throughput from 225 yards away when the (omnidirectional) AP was in doors: http://www.evdoinfo.com/content/view/5077/64/ http://www.evdoinfo.com/content/view/5077/64/ As far as I know, the only better access points are the newer Ruckus models that replaced it. I am really excited to be getting one later this week. :)
  - robotresearcher 10y ago

derefr 10y ago

Random thought: is there a reason we couldn't construct apartment buildings such that each tennant had a Faraday mesh embedded in their shared walls, but not in exterior-facing walls? It would do strange things to cellular and broadcast radio, but it wouldn't destroy them, I think.

colanderman 10y ago
IANAP but I would think such a cage would cause WiFi to reflect internally, causing as much if not more trouble than noisy neighbors. The "real" solution is for people in dense apartment buildings to just turn their damn Tx power down, but that's a prisoner's dilemma if I've ever seen one.
- PaulHoule 10y ago
  Actually WiFi was designed from the very beginning to do well despite reflections. My thesis advisor knew somebody who was applying ideas from "quantum chaos" to make WiFi robust to various environments at Bell Labs, back in the 1990s, before Carly Fiorina bankrupted Lucent.
- derefr 10y ago
  It's a prisoner's dilemma in the case where everyone controls their own wireless APs, sure. In the case where the building is served by one major ISP, and they provide combination gateway+APs, I could see the ISP deciding to "solve" the problem by turning the whole building into one AP mesh (with only one AP actually active per unit sphere) where each client gets a VLAN with tagged QoSing over the last-mile "backplane" back to their own gateway. Though, if you're going that far, you may as well just call yourself a WiMAX provider and tell people their gateways are just extension picocells for the network, rather than end-user equipment. Which is basically what you get already from the ISPs that offer "public wi-fi for customers at our hotspots" (i.e. broadcast by all APs on our business plan), except that said wi-fi would be the only product, and would be served by residential gateways as well.
- korethr 10y ago
  I actually tried to approach this problem in my own apartment complex. The effort died almost immediately. Very few consumer wireless access points even expose Tx power as a configuration parameter at all, even buried in an "Advanced Settings" section somewhere. You're lucky if they even expose channel selection at all. So with the craptastic firemware of most consumer wifi APs, the AP hops on channels 1, 6 or 11, and stays there, screaming at full power. And the consumer, even if they know enough about radio to realize such is suboptimal, can't do anything about it without changing the firmware or buying a more expensive device.

drcongo 10y ago

I live in London (my neighbours are a LOT closer than 1/4 mile) with a shitload of devices on my WiFi and I can still happily stream 4K TV while my my entire family uses iPads or laptops. Am I breaking the laws of physics?

wang_li 10y ago
>Am I breaking the laws of physics? No, you're just using subjective feelings rather than objective measurements. 4K doesn't specify a particular bit rate. If there is going to be a productive discussion, it needs to be acknowledged that there is a huge difference between streaming 1080p and Bluray 1080p.
- drcongo 10y ago
  Why would anyone stream a Bluray?
  - wang_li 10y ago
    No one would want to stream a Bluray. The point was to highlight that there are very different things that are still described by "1080p" and what is more important is the bit rate and codec rather than the common 4K, 1080p, 720p, or even "HD video" names.
    - drcongo 10y ago
      I don't know why you're even talking about 1080p, though I think I vaguely get what you're trying to say.