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T-Mobile Promises Big LTE Boost From 5GHz Wi-Fi Frequencies (arstechnica.com) 64

"T-Mobile USA is ready to deploy a new LTE technology over the same 5GHz frequencies used by Wi-Fi following U.S. government approval of the first 'LTE-U' devices," reports Ars Technica. "The Federal Communications Commission today authorized the first LTE-U (LTE for unlicensed spectrum) devices after a controversial process designed to ensure that cellular network use of the 5GHz band won't interfere with Wi-Fi networks." From the report: LTE-U will help T-Mobile achieve its goal of offering gigabit LTE speeds, the carrier said. Verizon Wireless is also planning to use LTE-U. The company said in September that it is "eager to deploy" the technology and developed an equipment testing plan, but it's not clear when a Verizon deployment will happen. Cellular carriers in the US generally hold exclusive licenses to spectrum, while Wi-Fi operates in unlicensed frequencies. Anyone can operate in unlicensed spectrum without an FCC license as long as they use certified radio equipment and comply with power limits and other technical requirements. The plan to bring LTE to unlicensed Wi-Fi spectrum set off an industry fight. LTE-U deployment plans drew opposition in 2015 from cable companies and the Wi-Fi Alliance, an industry group that certifies equipment to make sure it doesn't interfere with other Wi-Fi equipment. Industry groups worked together to develop a "Coexistence Test Plan" to prevent interference, and the Wi-Fi Alliance said it's satisfied with the result even though the new testing is voluntary rather than required by the FCC.
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T-Mobile Promises Big LTE Boost From 5GHz Wi-Fi Frequencies

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  • by hackwrench ( 573697 ) <hackwrench@hotmail.com> on Wednesday February 22, 2017 @08:24PM (#53914689) Homepage Journal
    And we need agreements on protocols for it.
    • The 60 GHz band [fcc.gov] (57-64 GHz) is open for unlicensed operation. It coincides with the resonance of oxygen gas, which rapidly attenuates any signal so the maximum usable range is about 1 km. That makes it ideal for things like home WiFi use (you can broadcast at higher power without interfering with your neighbors' WiFi at the same frequency), while strongly discouraging companies trying to use it for long-range commercial service like T-Mobile is planning in TFA.
      • Or anything solid really. If you have line-of-sight it works pretty well but get anything in the way, and you can have serious issues. I tried it for wireless HDMI and it wasn't able to maintain a solid signal over about 25 feet because there was an interior wall in between the transmitter and receiver.

  • by UPZ ( 947916 ) on Wednesday February 22, 2017 @08:26PM (#53914697)
    Can someone in the loop comment whether LTE-U is going to interfere with home and work wifi or not?
    • Of course it is. 5 GHz WiFi will be more fucked than 2.4 GHz is now.
      Here's what happened. The "W-iFi Alliance" got the ol' wink wink, nudge nudge from telecoms reminding them that as 5 GHz gets taken over, it'll just create demand for new WiFi spectrum, standards, licensing, and products.

  • by Harlequin80 ( 1671040 ) on Wednesday February 22, 2017 @08:28PM (#53914705)

    Lots of RC models use the 5.8ghz spectrum as their video transmitter band. Technically most of the power limits are 25mw, but that power output severely restricts range and is highly effected by objects such as trees. As a result people often run switchable transmitters that are 25/200/600mw and sometimes higher.

    It's one thing to momentarily effect a localised wifi network. Another thing entirely if you are taking out someones phone calls.

  • by Anonymous Coward

    Letting the carriers pollute 5Ghz unlicensed bands should have been killed. The carriers sit on massive amounts of licensed spectrum and do not deploy with it. Should be a use it or lose it deal. Of course Qualcomm came up with this idea so they could sell more chips.

    Really hoping they do not try deploying in rural areas as most people there depend on WISPs for decent internet and not some crippled carrier "unlimited" data plan.

    • by Z00L00K ( 682162 )

      Don't expect that to happen with the FCC now being under the control of Trump administration. Then it's all about money.

      Back to wired internet at home to ensure a reliable net.

  • by 140Mandak262Jamuna ( 970587 ) on Wednesday February 22, 2017 @08:40PM (#53914763) Journal
    Unorganized individual home wi-fi owners and users on one size. Mega telecom companies with deep pockets full of government lobbyists, money and politicians on the other side. Both allowed to use the home wi-fi spectrum. You don't have to be Einstein to see what is going to happen.

    There will be so much of interference with home wi-fi people will be forced to use mobile data. Or string cat-5 cables all over their homes to wired ethernet to every room.

    • by Anonymous Coward on Wednesday February 22, 2017 @10:25PM (#53915177)

      How come they are using the WI-FI band instead of
      the old analog television frequencies they were supposed to use for this very purpose?!

      • by Z00L00K ( 682162 )

        The analog TV bands are not very suitable for high capacity demands. Most of those bands are already being claimed for other purposes as well. And digital TV still chews up quite a bit of those bands.

        Lower frequencies also means bulkier antennas on the mobile devices - or less efficient antennas. So there's no real point in trying to reach for those bands.

        Also see this allocation chart [doc.gov], even though it's a bit dated it's still interesting. It seems to have a segment between 11.7 and 12.2 GHz that is planned

    • by SeaFox ( 739806 )

      Unorganized individual home wi-fi owners and users on one size. Mega telecom companies with deep pockets full of government lobbyists, money and politicians on the other side. Both allowed to use the home wi-fi spectrum. You don't have to be Einstein to see what is going to happen.

      So you don't think the FCC should side with the telecom companies carrying people's emergency calls vs. the home users posting shit on Facebook?

    • by currently_awake ( 1248758 ) on Wednesday February 22, 2017 @10:48PM (#53915249)
      This plan looks to have 2 huge benefits: 1-Wiping out Wifi competition. 2-Not having to pay for a spectrum license.
    • Maybe, depends on amplitude of the blowtorching towers; keeping in mind inverse square law. In addition, 5Ghz (and higher frequencies) don't penetrate solid objects nearly as well as 2.4Ghz and below. Yet paradoxically 5Ghz is better in a home/office environment over 2.4Ghz because the SNR is much better from lack surrounding interference.

  • I just had to buy one to get band-12 support. Here comes another new phone.
    • by AvitarX ( 172628 )

      Only when you need the speed.

      Since this band has poor penetration it's unlikely to improve overall service until the 50 or so mbps they currently offer feels slow.

    • Designed obsolescence works.
    • I bought a Moto G after seeing initial specs with band 12 support, but Motorola removed support for it in the US (partly at the insistence of T-Mobile). I've had some issues in the midwest with call+data and am almost positive band 12 support would help. What did you end up buying?
  • These articles are light in details and anything involving LTE is mostly incomprehensible to those of us who aren't in the industry. However I did find one report [lteuforum.org] that makes it look like they will be transmitting at 46dBm -- 40 watts -- in the "underutilized" 5GHz band. Such high power levels feel incompatible with the claim of coexistence and more like a move to drown out unlicensed WISPs.

    Also, LTE-U seems to be designed to function only if the operator also owns a licensed LTE control channel. If this t
    • by DewDude ( 537374 )
      I believe the 46dBm is for the LTE Control channel base; speaking of which...the one document seems to deal solely with SDL (supplemental downlink) version of LTE-U. The unlicensed stuff is limited to 30dBm (1 watt) or 24dBm (250mw)
      • Point to Multipoint transmitters in unlicensed ISM bands are limited to 36dBm EIRP. Point to Point transmitters in those bands are limited to 48dBm EIRP.

      • by Brianwa ( 692565 )
        I'm absolutely willing to believe that I'm misinterpreting those tables. On second look is lists "Macro Tx power" as 46dBm and "eNB Tx power" as 24-30dBm. Without knowing the lingo it's hard to say but that could mean that the 5GHz stuff is limited to a more reasonable power level.
    • by ezdiy ( 2717051 )
      > why not open it up for everyone?
      Because it would be much worse than wifi then. LTE is fast because it is very, very coordinated, down to client station level. That can be accomplished only by strict regulation, basically government says that you can run only specific protocol on a given band.

      The document linked brags about how LTE-U is better than wifi. Of course it is, because it uses separate (licensed) band for cooperative signalling, whereas WiFi (or LTE completely in unlicensed band as you sa

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