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WiFi Signals In Between Television Frequencies

compgenius3 writes "The FCC unanimously voted today to allow wireless providers to use the frequencies between television stations to broadcast WiFi in rural areas. Broadcasters argue that this will cause interference on television stations but the FCC chairman says otherwise." Update: 05/18 23:40 GMT by T : compgenius3 points out NAB president Edward Fritts' skepticism of the plan, as reflected in this press release citing fears of intereference to over-the-air broadcasts.

23 of 193 comments (clear)

  1. A valid concern by erick99 · · Score: 5, Informative
    From my experience as a ham radio operator (KE3PB) I know that RF interference is certainly possible unless every precaution (and then some...) is taken. There can be harmonics, spurious signals, oscillators, etcInterference in this case is a very valid concern but one that can be adequately addressed if all parties work cooperatively together.

    Happy Trails!

    Erick

    --
    http://www.busyweather.com/
    1. Re:A valid concern by mstovenour · · Score: 5, Informative

      I agree. The current regulatory environment makes it more and more important to have abuse monitoring and enforcement of the strict transmission rules. However, I only see regulations loosening up with no effort to extend monitoring and enforcement. This trend is likely to result in serious problems from the consumer's perspective.

      I live in an area that is already targeted by wide area WiFi and other technologies. I occasionally experience 1 or 2 hours where I cannot receive broadcast TV, FM radio, or even weather alert radio broadcasts. During the event I cannot receive broadcasts at my home or FM radio in my car within a mile or so. I strongly suspect that it is a wireless operator in my local area but proving it will take some serious effort on my part. I always notice when the event begins because my wireless mouse stops working.

    2. Re:A valid concern by doon · · Score: 4, Insightful

      I don't think that people in "rural" areas who depend on broadcast TV (trailer parks?) will go for the satellite option. You have no idea about High Class White trash living do you? My brother installs DSL for a rural telco. You probably wouldn't belived the stories I get to hear about the rusted out trailer with a DirectTV dish on the side, a Harley and a mustang (the car not the horse) in the driveway, and how he has to climb over all sorts of crap/garbage to get to the computer. It is mostly that their priorities are different.
      Please don't take this as a bash against trailer parks, I know a bunch of really great hard working people that happen to live in a trailer park, but I have also seen some pretty odd things..

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  2. This is great news! by ViolentGreen · · Score: 4, Insightful

    This will provide millions of people who cannot get wired broadband with an alternative along with a possible cheaper alternative for those of us who can but are too cheap to get it.

    Perhaps it will drive the wired broadband prices down as well. That way whoever wins the election can take credit for it.

    --
    Not everything is analogous to cars. Car analogies rarely work.
    1. Re:This is great news! by celeritas_2 · · Score: 5, Funny

      Finally no more taking the buggy to town to download the latest Mandrake!

      --
      -- Checking emails and kicking cheats `till the day I die.
  3. What about FM? by justforaday · · Score: 5, Insightful

    Doesn't the entire FM range fall between channels 6 and 7? Why aren't the TV stations getting pissed off at the FM stations???

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    1. Re:What about FM? by Professor_Quail · · Score: 5, Informative

      Yes, channel 6 is 83.25 Mhz, channel 7 is 175.25 MHz...channels 2-6 are 'VHF-LO' and 7-13 is 'VHF-HI'

      UHF starts at channel 14 @ 471.25 MHz...

      See this page for more info.

    2. Re:What about FM? by jgabby · · Score: 5, Informative

      The TV stations aren't pissed off at the FM stations because TV and FM don't have to share any spectrum, and FM is also a licensed and regulated service. There is a nearly 100 MHz break between channels 6 and 7 used for FM, Aircraft navigation and communication, and various other things.

      This is different because it proposes using 'unused tv channels' to carry unlicensed signals. (Take note that this is also different from what is implied in the headline...this is not 'the space between TV channels,' it is full channels.)

  4. This is bad by argoff · · Score: 4, Funny


    Now we won't have quality material on TV ... oops nevermind

  5. Wardrobe Malfunction by BenBenBen · · Score: 5, Funny

    Won't someone think of the children?

    It's not enough that the liberal media broadcast a *nipple* during a family show, now they have to fill the bits between stations with the internet, which Fox News told me is full of degrading pornography!.

    I for one am angry about this political correctness gone mad, and would like the FCC or DoJ to take some of my rights away in response.

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  6. Good Move by randall_burns · · Score: 5, Interesting

    Commercial broadcasters haven't really done much for the spectrum they were given. IMHO there should be substantial taxes on commercial use of spectrum. Theoretically, it would seem that Wi-Fi could deliver much more content than is now done with the spectrum the broadcasters are using. Perhaps we ought to look at completely eliminating the television spectrum and replacing it with Wi-Fi.

  7. Re:test by erick99 · · Score: 4, Informative
    Sorry for this post. I meant to do the following: This article does a pretty good job explaining how to solve RF interference problems. It is also instructive as to how the interference occurs.

    Happy Trails!

    Erick

    --
    http://www.busyweather.com/
  8. The chairman should know by Guy+Innagorillasuit · · Score: 5, Funny

    Broadcasters argue that this will cause interference on television stations but the FCC chairman says otherwise.

    I'm sure with his broad experience and expertise in the field Chairman Powell should be trusted on this matter. Where do these broadcasters get off questioning the word of a man of such stature in the industry? /sarcasm

  9. This This...Could Could...Cause Cause...Ghosting.. by Cheerio+Boy · · Score: 4, Funny

    Kind of like repeated Slashdot articles:

    http://slashdot.org/article.pl?sid=04/05/14/2154 247&mode=nested&tid=103&tid=129&tid=137&tid=188&ti d=193&tid=99

    Not exactly the same signal but close. ;-)

    In all seriousness does anybody else see this as an attempt to lock in an approved set of wireless equipment and keep people form building their own wans?

    --

    "Bah!" - Dogbert
  10. Sure but it goes both ways by TechnoWeeniePas · · Score: 5, Insightful

    Sure there might be some leakage...and the channels may get some interfearance...but that would mean that the networking signal would be getting interfearance too. And hence they will move to a "cleaner" frequency to lessen the problem...so if there is a problem its a problem for both...and hence they will work together to avoid such problems.

  11. What a relief! by YodaToo · · Score: 5, Funny

    I thought my spooky blonde daughter was communicating with poltergeists on channel 17.35. Turns out it was just WiFi.

  12. Trailer Parks? by gregarican · · Score: 4, Informative

    Have you driven by one lately? There are a surprising amount of satellite dishes at some of them. Even before all of the DirecTV and Dish Network varieties there were those behemoth dishes sitting next to the cable spool/picnic tables.

  13. I'd be the first to move over. by ctime · · Score: 4, Interesting

    Lower Frequencies = Better reception, wall piercing bandwidth. This is two fold, as your signal is going to simply work "better" for not only you, but john q. hacker sitting outside your building (or say 4-5 stories down inside your building should still get great reception.) Then again, this isn't really being sold as residential grade wireless, but rather transit links to and from customers. This is really where it's going to shine.

    If they do come out with AP's that run on this sub 700mhz spectrum, I'd be the first to buy them and ditch the near-microwave oven freqnency of 2.4ghz. That just seems like we're asking for trouble.

  14. darn tootin' Re:A valid concern by swschrad · · Score: 4, Informative

    the FCC is totally clueless in this iteration. there is a reason the space between TV channel assignments is called "guard bands," it keeps interference from generating third signals in the receivers (heterodynes, if you want to check the engineering details) that fall in the intermediate tuning circuits and mung up the signal. heterodynes with a strong local signal can wipe a whole TV out. and since there is no shielding worth noting in a commercial set, this means whoever puts up a wi-fi is responsible for zoning out the neighborhood.

    there would of course be little impact if the darned TV sets were shielded from RF interference. they aren't because it would cost a few quarters to do it, at worst case $5 to the retail buyer when they wave plastic at the best buy counter.

    if you have tried to put a cable TV or satellite box under your TV set, you know what I mean; screens full of little electronic worms.

    unless FCC mandates retroactive shielding and all future sets being shielded before sale, this will become a nightmare.

    ex-broadcaster, ex-ham, ex-recording engineer, I know interference is real and ugly. don't make any more.

    --
    if this is supposed to be a new economy, how come they still want my old fashioned money?
    1. Re:darn tootin' Re:A valid concern by kandrewnet · · Score: 5, Interesting

      I am an ex-broadcast engineer and can guarantee that they aren't using the guard bands between TV stations - because there are no guard bands! Each channel butts up next to the last one.

      Interference is avoided by not assigning two adjacent channels in the same market.

      Television channels are 6Mhz wide. A Wi-Fi signal occupies 30Mhz so I'm guessing they will need 7 channels in a row with nothing broadcast (5 for the spectrum needed with 1 on each side to avoid interference).

      Interference avoidance is nothing new to broadcasters. Aside from television channels assigned they also have had to deal with microwave live trucks, satellite transmissions, etc.

      Andrew

  15. It depends by bsd4me · · Score: 4, Informative

    OFDM is used for over-the-air digital TV, and it is fairly robust to nasties. A digital receiver can eliminate interference to an extent through adaptive processing, or compensate for it through FEC, but you can always get to a point where interference and/or noise will wonk a signal (eg, sun outages in geostationary satellite applications).

    --

    (S(SKK)(SKK))(S(SKK)(SKK))

  16. I'm sure Hollywood loves this. by Mr.+Neutron · · Score: 4, Insightful

    Anything to further diminish the viability of broadcast TV, with all of its pesky "fair use" and legalized home recording. Of course, once everything is HDTV, and all receivers everywhere have built-in, FCC-mandated DRM, there will be less to worry about.

    [/tinfoil-hat]

    --
    dinner: it's what's for beer
  17. Rural by Rick.C · · Score: 4, Insightful
    Most "rural" areas in the US can only pick up two or three over-the-air TV stations. If you can only get channels 3, 7 and 10, who cares if someone is using frequencies between 8 and 9 or between 12 and 13 for WiFi?

    As the article says, the WiFi gear would have to be responsible for scanning the spectrum for existing broadcasts (and other WiFi gear) and finding a quiet spot to use.

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