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Wireless Networking

Cellphone Carriers Try To Control Signal Boosters 231

digitaldc writes "[Repeaters], which cost from $250 to $1,000, depending on how much they increase a signal, work by first capturing cell signals through an external antenna, ideally affixed to the roof of a dwelling. A coaxial cable then transmits the signal inside the house to an amplifier and internal antenna, which strengthen and retransmit it to cellphones... In March, CTIA-The Wireless Association, which represents cellular service providers, filed a complaint with the Federal Communications Commission demanding stricter regulation of signal boosters."
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Cellphone Carriers Try To Control Signal Boosters

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  • Paywalled (Score:5, Informative)

    by MetalliQaZ ( 539913 ) on Thursday November 18, 2010 @11:54AM (#34268646)

    I clicked through Google news to get it "free"... []

  • Re:Why? (Score:4, Informative)

    by Enry ( 630 ) <> on Thursday November 18, 2010 @12:27PM (#34269218) Journal

    AT&T and Verizon don't sell boosters, they're femtocells []. Same result (better signal), different way to get there (femtocells rely on your existing Internet connection).

  • Re:Paywalled (Score:4, Informative)

    by CityZen ( 464761 ) on Thursday November 18, 2010 @12:30PM (#34269254) Homepage

    Because news sites *want* search engines like Google to see their content, so that people searching for stuff will be directed to them. And they want the people following links from Google to come back. So they try follow the drug dealer's model: we'll give you a bit for free, so that you'll come back and pay for more later. Of course, smart people figure out how to not pay ever, but that's only a small percentage of viewers.

  • by TWX ( 665546 ) on Thursday November 18, 2010 @12:30PM (#34269264)

    An old ham radio saying is all an amplifier does is amplify crap.

    That may be true if the device is solely placed where the signal is poor, the tuner is inadequate, the antenna is bad, and the amplifier has nothing to work with, but the solutions that I've seen nullify many of these problems.

    These devices have two parts. One part, located ideally outside, high up, talks to the cell company. the other part, located where the poorest signal is normally, talks to the cell phones. On top of that, these devices have much larger antennas than the phones do, and with more size they can also have better radio tuners. So, you're not amplifying crap, you're getting a better signal and forwarding it to another device that is in an area that can't get the original.

  • by ( 1265320 ) on Thursday November 18, 2010 @12:32PM (#34269294) Homepage
    No, they DON'T like boosters.

    this is a fundamental issue in the way wireless communications works, when you stand in one spot in a city within range of three towers, your cell phone attempts to modulate itself onto a portion of the spectrum that will allow it to speak. This in turn means that all three towers now can hear you.
    because all three towers can hear you, but only one is responsible for carrying your traffic the others make that channel unavailable to the people within range of the other two towers. the only thing the towers can do is reduce power to the quadrant the handset is in, allowing people closer to the tower to use it at the same time. even THIS however is limited: if the MobileStation can still reach the other two towers, they can't reduce power far enough to allow anybody else to use those channels.

    once you install powered signal boosters, your cell phone now may be able to reach twenty towers. those towers each have a limited number of 'slots' available for users to use, (infact the number of GSM channels is currently around 32, though through timeframing of each channel there are 7-14frames per channel/second) meaning that you effectively are now multiplying your capacity based on how many towers you can hit.

    the issue here is NOT with people that are in small towns/remote location, telco's are happy to let people put up their own repeaters to enlarge the telco's network at no cost to the telco. the issue they have is that people in downtown apartments with lead paint think that by hitting every tower in 15 square blocks just so they can repeat it indoors for one customer is a good thing.

    by using the air to communicate: you have to learn to share it with others. we only have one global collection of air for which EMR can radiate.
  • by Shakrai ( 717556 ) on Thursday November 18, 2010 @12:42PM (#34269448) Journal

    because all three towers can hear you, but only one is responsible for carrying your traffic the others make that channel unavailable to the people within range of the other two towers

    This is a overly simplistic explanation. GSM uses frequency hopping for the uplink (i.e: phone to tower) channel to mitigate this sort of interference. The other towers don't perceive your phone as anything other than random background noise. CDMA uses a different mechanism (spread spectrum using a pseduo-random code) to achieve the same results, plus it has the added benefit of being able to do soft-handoffs [], i.e: your phone is literally talking to multiple towers at the same time.

    The whole point of digital technology is to enable multiple users to share the same channel. Repeaters don't really defeat this. What they can do is increase noise along with signal, usually to the detriment of any phones within range of them. The carriers are rightfully peeved about them because they've spent billions of dollars to license the spectrum that they use and were supposed to have exclusive rights to deploy devices that transmit on that spectrum.

  • Re:Why? (Score:2, Informative)

    by rally2xs ( 1093023 ) on Thursday November 18, 2010 @12:44PM (#34269476)

    Your house is built with a special alloy of Zirconium and Iridium, and designed by an architect who was a deacon in the church of worshippers of Goser, the traveler. Your place not only kills electromagnetic radiation, it is also spook central.

  • Re:Paywalled (Score:2, Informative)

    by Anonymous Coward on Thursday November 18, 2010 @12:45PM (#34269514)

    I don't get it, why does it work that way?

    Why? They want Google to get through so their site gets indexed. Then people search for this information, click the search result, and receive the sales pitch for the paywall.

    This is the link from that does NOT show a paywall: []

    This is the link from the Slashdot summary that DOES show a paywall: []

    So apparently it's all determined by the tail end of the URL.

    Opinionated rant: I can understand a paywall for specialized niche publications but for news? That I can obtain from many different sources? Really? This business model is defective and needs to go the way of the dinosaur. The sooner it does that, the better.

  • by b0bby ( 201198 ) on Thursday November 18, 2010 @12:46PM (#34269542)

    Mod parent up - boosters sold by others still use their towers, femtocells sold by the carriers use your internet connection. If they can outlaw the boosters, the carriers win twice.

  • by Firethorn ( 177587 ) on Thursday November 18, 2010 @01:09PM (#34269922) Homepage Journal

    As far as I know, what AT&T and Verizon are selling are 'microcells', basically miniature cell towers that convert your phone's signal to VOIP to get to their network; it uses your home's internet connection.

    These are a bit distinct from cell phone boosters, which still has you using your phone company's towers by taking your phone's (likely) .25 watt max power signal and amplifying it to the maximum legal power of 2-4 watts*, often using a directional antenna mounted somewhere outside - like the roof.

    This would be fine and dandy at my old place which was like 30 miles from the closest tower. Not so good at my parents, who are in some sort of 'signal depression' such that they have even less signal inside, but lots on the roof, the antenna is only about a mile away. Still, most have automatic gain control, so while one on my house might use the full strength(it's got a lot of distance to cover), even with a directional antenna to give me 4-5 bars, my parents might 'whisper', only needing to avoid the interference that the house adds combined with a better line of sight with the added height of the roof.

    I did quite a bit of research on boosters because, well, I had lousy signal in my old(rural) place, but balked at the $500 to do a proper job of it, and it was before microcells started becoming available. Then I found out my job was moving me, and it became academic.

    *Actual level dependent upon frequency, country, and other factors.

  • Re:Paywalled (Score:4, Informative)

    by autocracy ( 192714 ) <> on Thursday November 18, 2010 @01:26PM (#34270248) Homepage

    Oh, that's BRILLIANT! Click on the first link, and you'll notice that r becomes 2. Open another browser on your computer and paste the new URL in... r becomes 3. By the time we've seen it on Slashdot, this url was hot-potatoed along four times from the first viewer.

  • by kriston ( 7886 ) on Friday November 19, 2010 @12:42AM (#34278568) Homepage Journal

    It's simple. Mobile phones were not intended for household use. The 1900 MHz frequency does not penetrate walls very well. Those services (AT&T and VZW) that do have 850 MHz spectrum have moved as much of their voice service and control channels down to 850 MHz as possible because it penetrates walls so much better.

    Sprint and T-Mobile are stuck in the 1900 MHz range in most markets. These are the majority of booster customers. The problem is that the boosters mess up an already weak service.

    In Sprint's case, it's exponentially worse, since CDMA only works because the handset and the base station carefully agree on power levels, and the booster removes that control, thus causing havoc all over the Sprint CDMA bands.

  • Re:Passive Boosters? (Score:3, Informative)

    by adolf ( 21054 ) <> on Friday November 19, 2010 @01:06AM (#34278662) Journal

    They work fine.

    It's just two antennas, connected together. In a car (which acts a bit like a Faraday cage), you might just think of it as a hole that allows the RF to leak in, plus a little bit more height.

    In my mostly-windowless work van, I've built my own: There is a through-mounted gain antenna on the roof, and a magnetic mount gain antenna on the inside, connected by a few inches of coax.

    Works well enough: I put it together after I was on my way to a job one day, and close to my destination there was a bridge out (I'd been ignoring the detour signs because I was close). So, I pulled out my trusty Droid, fired up Google Maps and, lo! There was no cell coverage. I spent half an hour trying to cross that body of water, and was late. Boo.*

    So, I threw it together out of spare parts. And the next time I was in that stretch of the woods, I had plenty of bandwidth. At a glance, it would appear that any of the stuff you linked to would behave similarly well. (My antennas probably have higher gain, but the off-the-shelf passive repeaters don't have the connector losses that mine does.)

    *: A paper map would've worked just as well, but wouldn't help me make phone calls in poor coverage areas, would've had non-zero cost, and wouldn't give me an excuse to drill holes in the truck. (I like drilling holes in automobiles.)

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