Slashdot Mirror

← Back to Stories (view on slashdot.org)

Ask Slashdot: Can Any Wireless Tech Challenge Fiber To the Home?

Posted by timothy on from the fibrous-and-lumpy dept.

New submitter danielmorrison writes: In Holland, MI (birthplace of Slashdot) we're working toward fiber to the home. A handful of people have asked why not go wireless instead? I know my reasons (speed, privacy, and we have an existing fiber loop) but are any wireless technologies good enough that cities should consider them? If so, what technologies and what cities have had success stories?

18 of 190 comments (clear)

  1. Short answer? by Sycraft-fu · · Score: 5, Insightful

    No.

    Long answer?

    Noooooooooooooooooooooooooooooooooooooooooooooooooooo.

    Sorry, but that pesky little Shannon's Law gets in the way. Fibre provides more frequency and better SNR than you'll get in the air, thus more bits. You can't get around physics.

    1. Re:Short answer? by Firethorn · · Score: 5, Funny

      Not just that. I could give fiber speed to ONE user in an area by wireless. To 10% of the population, much less 'everybody'? Not happening.

      BTW, 'Shannon's Law' got a snerk from me. Another acronym crossover from two different fields.

      Data Transmission: Shannon–Hartley theorem
      Firearms: Shannon's Law, which forbids firing guns into the air in Arizona. You're living in the wrong area if ballistic lead is interfering with your wireless signal on a routine basis. ;)

      --
      I don't read AC A human right
    2. Re:Short answer? by i.r.id10t · · Score: 4, Funny

      I get online via a RFC1149 compliant system, and first phase dove season starts Sept 26 here in Florida. I'm expecting a lot of packet loss. Of course, the packets that do make it through will be traveling extra fast...

      --
      Don't blame me, I voted for Kodos
    3. Re: Short answer? by Firethorn · · Score: 3, Informative

      Most FTTH use cases could be replaced with this, although FTTH can roll tomorrow and this is still vaporware - 15 years is a lot of productivity.

      But the speed of fiber keeps marching along, even as that of wireless creeps up. You also run into that wireless transmission effectively takes up a lot more 'space' than fiber - so you're always sharing the medium.

      You can do a lot with directional antennas, but still not as much isolation as available with fiber. So you have to consider the bandwidth not in isolation, but when all your neighbors want fast wireless internet as well.

      --
      I don't read AC A human right
    4. Re:Short answer? by threephaseboy · · Score: 2

      They are doing that to trade off bandwidth for better latency.

      --
      .
    5. Re: Short answer? by StikyPad · · Score: 2

      Any modulation that can be used on OTA transmissions can be used in an isolated medium, whether it's fiber, or coaxial cable, or waveguide, or what have you. The question is the medium, not the media, and isolated mediums will always be more efficient. Always.

      Moreover, any OTA communication has to be reduced to an isolated medium for processing, so even if, magically, we could get faster speeds through OTA, we'd still be bottlenecked by those pesky endpoints.

      --
      https://www.eff.org/https-everywhere
    6. Re:Short answer? by Solandri · · Score: 3, Interesting

      Data Transmission: Shannonâ"Hartley theorem

      It's worth noting that current trends in wifi technology are moving in a direction which overcomes Shannon's law. The theorem assumes a shared communications channel. That is, if you transmit your signal at -45 dB, then everyone else using that same channel sees -45 dB of noise (your signal is noise to them).

      Beam-forming and MIMO (multipath) techniques subvert this assumption. For a visual analogy, it's why you can see your smartphone display in the sunlight, even though the sun is much, much brighter (its signal strength at optical wavelengths far exceeds your phone display's signal strength). Although the sun is very bright, the light it gives off is highly directional. By using sensors (the lens structure of your eyes) which can "tune in" to light coming from a narrow angle, you can basically filter out all that sunlight noise and pull out a clear signal from the smartphone display.

      We're still a long way from this being able to beat out a direct fiber connection. But with phased array antennas (basically what MIMO does except using a lot more transceivers for much finer angular resolution) acting like a "lens" to "focus" radio waves, it's not outlandish to think that in the future all wireless communications could effectively be point-to-point with little to no interference from other wireless sources. Even though everyone is transmitting at the same frequencies, the highly directional nature of the transmissions would mean Shannon's law almost never comes into play, and you get to use all that bandwidth as if you were the only one transmitting on it.

  2. I run a WISP. No. by hawkeyeMI · · Score: 5, Informative

    Wireless can do as well as fiber, but it's going to cost a LOT more and you'll have trouble scaling it. I run a small rural wireless ISP, and while wireless is cheap and fast to deploy, it's not fiber, and it's never going to be. That said, with a good high point and backhaul, you can start providing speeds up to 40Mbps for less than $5k.

    --
    Error 404 - Sig Not Found
    1. Re:I run a WISP. No. by jabuzz · · Score: 2

      No you can't. If you have a single core of single mode fibre between any two points I can right now today go and buy everything from 100Mbps, to 10Gbps Ethernet SFP's that I can stick on either end for any distance up to 80km. That is a really tough call for wireless to match. You are looking at specialist systems for starters. Not something I can order up with a few mouse clicks and a credit card.

      However if I have two cores of single mode fibre (and random single mode fibre layed a decade ago will do) I can right now today go and buy anything up to 100Gbps ethernet optics that again will do any distance up to at least 80km. I am not sure there is any wireless gear that does 100Gbps that you can buy for production today.

      However it gets worse because you can get 1Tbps systems operating over single mode fibre that will run over existing single mode fibre for like 1700km, though this is specialist telecoms stuff it is available today for production use provided you have sufficient cash to flash.

      Back in the more off the shelf market the 400Gbps ethernet standard is being worked on right now and will again run over that bog standard single mode fibre you already have in the ground and on the poles. I would expect this to be purchasable off the shelf within the next five years again with at least 10km and more likely 40km or 80km options.

      An interesting point is that at least here in the UK the 4G network unlike the 2G and 3G is all being back-hauled with fibre. If you know what you are looking for you can see all the roadworks for the ducting to carry the fibre going into the masts. That 4G is being back- hauled with fibre should tell you everything you need to know about the limits of wireless.

  3. Nothing New Under The Sun, Except This by synaptic · · Score: 2

    Wireless communications may become more interesting in the future thanks to this pioneering research: http://www.nature.com/articles...

    See also the theoretical paper: http://journals.aps.org/prl/ab... (http://arxiv.org/pdf/math-ph/0703059.pdf)

    It's not clear what the implications are for signal loss or if this is more of an illusion akin to beam steering.

  4. Wireless or not, still need a fat pipe... by __aaclcg7560 · · Score: 4, Interesting

    When I briefly worked at Cisco's wireless division a few years ago, I learned that their ideal customer was a hospital. Medical devices on a wireless network requires a higher level of reliability and uptime than the typical corporate or home environment. If Cisco gets wireless right for the hospital environment, they get it right for everyone else.

    Although hospitals are willing replace their wireless access points (APs) with newer models every X years, they're reluctant to upgrade the closet switches that connects the APs into the network. The more bandwidth is pushed through the APs, the more bandwidth capacity is needed for the switch. Higher bandwidth switches are much more expensive. That was the problem for the new 1Gb APs in 2013. You can connect 32 1GB APs to a switch, but the fiber link for the average switch maxes out at 10Gb. If bandwidth is constrained in the closet, the benefits to upgrading to high-speed APs will be limited. A big problem for the marketing department to figure out.

    If you think a hospital scenario is bad, trying getting local government to pony up a fat pipe for everyone in the neighborhood to have high-speed wireless.

  5. Depends on desired service. by allquixotic · · Score: 2

    It all depends on how much bandwidth and how much of a data allowance each customer wants/needs.

    If they expect to suck down a dedicated 100 Mbps pipe per household 24/7, then no, wireless anything won't do that, even if you expand outside the scope of WiFi to other tech like 4G.

    If, on the other hand, either their desired bandwidth, desired data allowance, or both, are sufficiently low, or the population density is sufficiently sparse, or any combination of these factors that turns out to be "enough", then you could substitute some kind of wireless technology for FTTP, whether it be LTE, WiFi, or something more pedestrian, like HSDPA/HSUPA.

    You could also go with high-freq (5 GHz and up) directional microwave from an office or a tower to specific receivers. If you don't want to install a receiver on each house (very expensive), you can shoot a beam to a street-corner box and then run copper or fiber to the premises. Saves you having to dig up the streets from the source to the street corner, at least. Fiber to the node. Kind of a hybrid. Sucks when it rains, though; sufficiently dense rain will diffract and/or block high freq microwave signals and make it useless.

    1. Re:Depends on desired service. by allquixotic · · Score: 2

      A standard pipe for *whom*? The few, the lucky, the elite? People living in small countries with a high standard of living and high median income? Here in the US of A, the vast majority of the population can't get access to a 100 Mbps pipe no matter how badly they wanted it, and they can't even afford to move to a place that would offer it.

      You are either among the lucky elite in the US, or you're in one of those countries that's actually forward-looking. In backwards countries like the US, we have to actually consider half-measures like wireless as a replacement for fiber: partly because of the incredible distances that have to be covered -- the U.S. is 29.74 times larger than Norway by area, and has zounds of people living in very sparsely populated areas where it's uneconomical to dig up the ground for miles for 2 people -- and partly because our government is ridiculously anti-consumer and pro-corporation, so ISPs only answer to the almighty dollar and nothing else.

      Calling 100 Mbps a "standard pipe" in 2015 is as obtuse and short-sighted as saying that having a top-of-the-line automobile was a standard item that every household owned in 1916.

  6. Here's a question for you to think about by Sycraft-fu · · Score: 4, Interesting

    Do those same techniques work on frequencies through all different mediums, or do they only work in the air? (this is a rhetorical question by the way).

    Whatever you can get in the air, you can get more in a cable or fibre. Sorry, that is just how it is going to be. Find the fastest wireless technology on the market, and then compare it to what you can get over a copper or fibre. Do it at any given point in history, and you see that it is always behind.

    There's a reason for that, and I gave the reason.

    1. Re:Here's a question for you to think about by jwdb · · Score: 2

      You're absolutely right that "multiple users" is the issue. You only have to look at DOCSIS, and what happens to that cable-based shared medium when everyone gets home from work and decides to start streaming. This is why ADSL can often offer better practical performance despite having a lower theoretical bandwidth. If you want consistent speed you need a dedicated channel.

      Yes, you can achieve this with a microwave link. It's easier to provide the necessary isolation with a bounded cable medium rather than manipulating the antenna pattern, however, so the medium is not irrelevant.

  7. Wireless electronics is like pipeless plumbing by MpVpRb · · Score: 3, Insightful

    Yes, it can be made to work, but a pipe is always better

    Need more capacity, add more fibers

    Once the spectrum is saturated, it's full

    Yeah, clever coding and compression can help, but it's still a finite spectrum

  8. Bandwidth over time by Firethorn · · Score: 2

    However, consider this. When the internet was just getting going, 320 video was enough, normally downloaded overnight/day to watch later.

    Then 320 became 480, moved to 640, 720, and 1080.

    Today, we're starting on '2k' and '4k' screens. From interlaced 30hz to progressive 120Hz, 3D, etc...

    --
    I don't read AC A human right
    1. Re:Bandwidth over time by multimediavt · · Score: 2

      However, consider this. When the internet was just getting going, 320 video was enough, normally downloaded overnight/day to watch later.

      Then 320 became 480, moved to 640, 720, and 1080.

      Today, we're starting on '2k' and '4k' screens. From interlaced 30hz to progressive 120Hz, 3D, etc...

      First of all, 2K is 1080p (1920x1080), and NTSC was 60 Hz interlaced at 29.97 SMPTE drop-frame frames; one odd, one even at 60Hz (our AC power frequency in the U.S.) to get ~30 full frames per second. The 120Hz number you mention is screen refresh rate not content frame rate, either 24 progressive frames per second (most cinematic titles) or 30 progressive frames per second (29.97 SMPTE drop-frame, still) for television.