Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 


Forgot your password?
Close
typodupeerror
×
Wireless Networking United States Hardware

FCC Allows Mix-and-Match Wi-Fi Antennas 200

Posted by michael from the net-gain dept.
Glenn Fleishman writes "We just filed a story at Wi-Fi Networking News about how the FCC recently and quietly approved rules that will allow the legal use of the Pringles can and other antennas. Currently, it's clearly illegal--even though it's incredibly easy--to swap out a manufacturers' antennas from a Wi-Fi access point with an antenna of your choosing. It's legal to sell antennas; not legal to deploy them. Call it the switchblade kit rule: legal to sell, but don't assemble. The FCC's new rule provides a middle ground: a manufacturer can certify their hardware with the highest gain legal antennas of each type (yagi, omni, etc.) and then end-users can swap in antennas of equal or lesser signal characteristics. It's an important move because it removes the potential for community wireless and individual users to be prosecuted for illegal antennas once new certifications are in place."
This discussion has been archived. No new comments can be posted.

FCC Allows Mix-and-Match Wi-Fi Antennas More

FCC Allows Mix-and-Match Wi-Fi Antennas

Comments Filter:

  • Death to RP connectors! (Score:3, Informative)

    by isd_glory ( 787646 ) * on Friday July 23, 2004 @03:08PM (#9782420)
    Does this mean that we can finally get rid of annoying antenna connector types such as RP-SMA and RP-TNC that were originally devised just to make it a pain in the ass to switch out factory antennas? I'd much rather be able to mix and match antennas and cables that can be easily found at local HAM shops.
    • Nope, the non-standard connector requirement is still in place.

      The reasoning isn't entirely absurd. They are trying to reduce accidental/ignorant violations.

    • Re:Death to RP connectors! (Score:4, Informative)

      by Ungrounded Lightning ( 62228 ) on Friday July 23, 2004 @05:17PM (#9784040) Journal
      Does this mean that we can finally get rid of annoying antenna connector types such as RP-SMA and RP-TNC that were originally devised just to make it a pain in the ass to switch out factory antennas?

      No. They explicitly kept that provision (including the part that required the manufacturers to switch to still newer pain-ion-the-backside unuque antenna connectors once third parties are marketing adapters for the old ones.)

      They want to make it enough of a pain to install an uncertified combo that you can't do it by accident and unknowingly. (Of course the fact that most of us have been unaware that hooking up a cantenna WAS illegal proves that's bogus. But it didn't stop them from continuing it.)

      IMHO they should have allowed the industry to collude to standardize one or a small set of connectors with defined signal limits for what the card can feed it on one side and what the antenna/transmission line can do on the other, and let the antenna and card vendors work to that. Then you could meet the FCC's targets with a O(M+N) rather than an O(M*N) solution, and eliminate the prolifertation of low-volume and thus pricey connectors.
    • Just use a pigtail with N connector.


      Alternatively, sacrifice the warranty and just solder a standard connector in (requires high-freq knowledge).


      Or do what those NZ guys did in earlier Slashdot post couple weeks ago, and use some USB dongle with a parabolic dish. Alternatively, enhance it with modifying the dongle to make its own antenna directional to improve the dongle-dish assembly properties.

    • I thought those connectors were old standards.

      Have you not found adaptor pigtails? It's not that hard.
    • Does this mean that we can finally get rid of annoying antenna connector types such as RP-SMA and RP-TNC that were originally devised just to make it a pain in the ass to switch out factory antennas? I'd much rather be able to mix and match antennas and cables that can be easily found at local HAM shops.

      Thats precisly why there are over 900 specs for antenna connectors used on part 15 wireless devices. So you can't do that easily.

  • Probably because.. (Score:3, Interesting)

    by Adam9 ( 93947 ) on Friday July 23, 2004 @03:08PM (#9782424) Journal
    They realized that such a restriction with small wireless networks would be very difficult to enforce. Or maybe they like the idea of community wireless networks without buying expensive equipment?
    • They realized that such a restriction with small wireless networks would be very difficult to enforce.

      In nearly every country wireless/RF enforcement is complaint driven, so a "small wireless network" that intereferes with another (possibly licensed) wireless/RF activity and those users complain, then the FCC may take action -- investigation and possibly enforcement in servere cases.

      The old days of spot checks by UK Post Office station inspectors and FCC inspectors are long gone. Old hams often have sto
  • Michael... Powell... is... evil!

    This can't be happening!

    • MP isn't evil. He's actually had, from the little that I've paid attention to his policies, a strong tradition of helping out techies and little tech companies, and minimizing government interference -- the sort of thing that makes most Slashdotters happy. He was concerned enough about the fact that independent techies and hobbyists weren't being represented that he set up a weblog. He's one of my better-liked bureaucrats.

      He got a *lot* of flack for condemning Janet Jackson for flashing her breast. Tha

  • sweetness (Score:2, Informative)

    by Awol411 ( 799294 )
    you can also use a peice of cardboard and aluminum foil http://www.techtastic.ca/articles/homemade-antenna .html
  • Call it the switchblade kit rule: legal to sell, but don't assemble

    Fully offtopic, but why are switchblades illegal in the U.S.? Is this a throwback to the 1950's era biker/greaser hysteria?

    Jason.
    • They aren't illegal everywhere; it's on a state-by-state basis. IIRC, there's only one state that has them as currently legal for civilians. Oregon, I think, but don't quote me on that. Also, for active duty military and police they're legal just about everywhere. Some very nice automatic knives are being manufactured these days.
    • Most states allow them for "collectors" but prohibit their sale or purchase. Oregon allows them for anybody, Florida allows them for concealed-carry permit holders.

      There's also a FEDERAL law which prohibits interstate transport/sale except to military and police.

      I think it's a patently idiotic law.
      • Oregon allows them for anybody

        I love living in Oregon.

        As a side note, like all weapons, you have to play by the rules of the house. Meaning my friend who would routinely bring his switchblade to school (why, I'll never know -- probably to look cool) back in high school was definitely breaking the law.

    • Apparently if you're going to stab someone, it's gotta be with a switchblade. It seems that authorities believe that criminals are too fussy to be carrying around any other kind of knife.

      It seems strange to me that a switchblade is illegal, but folding knives are sold widely. What the hell? Does the fact that it automatically pops out somehow encourages criminal acts?

      "Oh yeah, I saw gonna stab that bastard, but unfolding my knife takes so much effort. So I just let him go. That foo' was lucky I didn't ha
      • You might think twice if you can't instantaneously pull a knife on someone. Just like you watch what you say when you know you're not anonymous, you behave differently when something takes a few seconds longer.
        • You might think twice if you can't instantaneously pull a knife on someone. Just like you watch what you say when you know you're not anonymous, you behave differently when something takes a few seconds longer.

          But you can pull a new knife instantly... My neighbor has something simmiler to this [buckknives.com] and I can whip that thing open as fast as you could push a button on a switchblade... So I'm not sure why they're illegal either.

          What I always found to be funny was butterfly knives being illegal as well... Those t
          • What I always found to be funny was butterfly knives being illegal as well... Those things take longer to open than a normal knife..

            Not only that but if my friends with illegal butterfly knives are any indication, you're probably far more likely to cut your own hand than to actually take down your opponent...
          • I knew kids in school who had butterfly knives. With practice you can open and close those things faster than the eye can see, and the kids who had those certainly got a lot of practice. They loved flipping the thing open and closed for hours on end when there were no teachers around. I never really thought of those kids as dangerous though, it was more like something to do with their hands when they were bored.
        • Agreed. If you're going to use a knife in a fight, it's best if the other person doesn't know you have a knife. Smart way is to hold it so the blade is hidden by your arm, rather than pointing out where the other person can see it And as the previous poster mentioned, you must be prepared to use it, not chat and hesitate. I've taken away quite a few knives because the person watched too much TV (I used to be a bouncer in a rough club, and had some previous training). Every one of them pulled out their knive
          • I'm curious, never having had much to do with knives other than in the kitchen. How is one supposed to hold the knife if not a waist level?
            • You pull the knife out, blade opposite the thumb, and use it. The whole thing, from identifying the threat to the 6th slash, should be about 5 seconds. Describing how is like describing color.

              -cp-

              • About right, a friend was stabbed coming out of a bar. He had a disagreement with a stupid white-trash soldier in a bar and my friend thought it politic to move elsewhere. He left the bar and as soon as he realised he was being followed he was stabbed in the side (near the kidneys). The guy was good, the weapon wasn't seen before hand and absolutely no warning of the attack. My friend survived though, long enough to report the perp to the police.

  • So all old antennae are now illegal? (Score:3, Informative)

    by gtrubetskoy ( 734033 ) * on Friday July 23, 2004 @03:13PM (#9782482)
    It's an important move because it removes the potential for community wireless and individual users to be prosecuted for illegal antennas once new certifications are in place.

    Doesn't this mean quite the opposite - if you have an antenna of questionable legality right now, after the certifications are in place it will become an uncertified and illegal antenna?

    • yeah.

      with the new certifications one could install aftermarket certified antennaes, self made(un-certified) would still stay just as illeagal as ever.

      still, being able to get at least some antennae choices would be good.
    • There's no question about illegal antennas now: there's nothing that's borderline. Either it's tested as part of a system and legal, or it wasn't and isn't. There are a few tiny exceptions that you might be able to make the case for, including certain kinds of one-off or homebrew antennas in certain cases.

      So it's virtually all illegal now and the new rules will allow a broad swath to be 100-percent legal once recertification or new certifications take place.
  • Has anyone ever been sued for WiFi antenna gains in the past 5 years? If not, then keep the pringle cans flowing.

    GroupShares Inc. [groupshares.com]
    • I did get a cease and desist letter from Pringles. They said that use of the chip container was not licenses for commercial use. Although Wilson sporting goods said that use of their tennis ball container was okay. Check with your alternative antennae provider for doing any wi-fi mods.

    • It's pretty hard to exceed the legal limit for antenna gain with a pringles can (unless you're using it in conjunction with an amplifier). 15 dbm card + 12 dbi cantenna = 27 dbm effective radiated power, which is significantly less than 36 dhm erp (4 watts), which is the limit for most applications.

      See also part 15 section 23 [atlasce.com] (home built devices), which seems to imply that its perfectly okay to build your own custom antennas in some situations regardless of what the article says.

      -jim

  • Amateur license holders have more freedom. (Score:5, Informative)

    by tgd ( 2822 ) on Friday July 23, 2004 @03:19PM (#9782540)
    Channel 1 is in a band that falls in spectrum assigned to amateur radio operators. That means, of course, we can legally transmit up to 2500 watts vs 50 milliwatts if that happens to be the lowest power we need to get the signal through.

    It also means we're licensed users of the spectrum, which trumps Part B and means a license holder could, technically, tell a neighbor to move off of channel 1.
  • This isn't really pertinent to the issue, but the article states that bongs are legal to sell, but illegal to use. This isn't quite true.

    The Article:

    Wait, you may askI can go to HyperLink Technologies or other companies and buy antennas with the right connectors and attach them to my Wi-Fi gateway. If its illegal, how can I buy this gear? Simple. Its legal to sell antennas; its illegal to use them. Its the same logic that guides the sale of bongs and switchblade kits.

    With bongs the case is that you can

    • Some states do not allow possession of drug-related items at all. Despite legal uses for them, it is not always legal to possess a "bong." It may have changed in the last ten years, but when I was in high school a friend had a bong in his backseat when he got pulled over. He had crossed the state line and went from Indiana (where he bought it) and was not five miles into Michigan when the cop confiscated the bong and wrote him a hefty ticket.

      My recollection of the exact details are a little foggy (not beca

      • Re:A minor note (Score:5, Insightful)

        by maximilln ( 654768 ) on Friday July 23, 2004 @03:30PM (#9782672) Homepage Journal
        Tony Chong, of Cheech'n'Chong, ran a glassblowing shop which made artwork glass tubes. The shop was taken down by the DEA and Chong was charged in court. I didn't keep track of the outcome.

        At the end of the day legality is determined by how badly they want to get you.
        • I was actually going to mention the case of Tommy Chong.

          It's definitely a grey area. There are many shops around that are blatantly catering to drug users (mainly pot smokers) that never get busted, but there are cases like Tommy Chong where it was decided that his products were drug paraphrenalia because of what they were sold with in the shops of some of his clients, that is, some stores that sold his bongs were selling clearly marijuana related goods (tshirts, wallets, etc.) and so his somewhat ambiguou
        • Chong was charged in court. I didn't keep track of the outcome.

          He was sentenced to 9 months in prison for it. [norml.org]

  • Wi-Fi Antenna Types (Score:5, Informative)

    by diagnosis ( 38691 ) on Friday July 23, 2004 @03:20PM (#9782557) Homepage
    I noticed that the article lists a bunch of different antenna types. I didn't know what they all were, so I looked some of them up and thought I'd share:

    The info in quotes is verbatim from http://www.radiolabs.com/Articles/wifi-antenna.htm l [radiolabs.com]

    Omni: (Omni-Directional)
    This is a standard antenna like you'd see on a cordless phone. Broadcasts the signal more or less equally in all directions.

    "An Omni-Directional antenna would serve as your main antenna to distribute the signal to other computers or devices"

    Yagi Antennas
    "Yagi antennas were the design of two Japanese people, Hidetsugu Yagi and Shintaro Uda, and are sometimes referred to as Yagi-Uda antennas...these antennas are typically very directional and are used for point to point."

    Yagis look like a ladder with one vertical bar in the center of each step.

    Backfire antennas
    "The backfire is a small directional antenna with excellent gain. They look similar to a parabolic dish, but the gain isn't as high."

    -----------------
    DrMovieMovie.com: [drmoviemovie.com]
    Witty movie reviews, eating contests, and a guy who once drank a gallon of milk in an hour.

  • illegal antennas are still illegal (Score:5, Insightful)

    by poot_rootbeer ( 188613 ) on Friday July 23, 2004 @03:20PM (#9782564)
    it removes the potential for community wireless and individual users to be prosecuted for illegal antennas once new certifications are in place

    No it doesn't. How'd you come to that conclusion?

    If a user has an antenna that exceeds the specs that have been certified for that antenna type with that device, it's still illegal to use and the user can still be prosecuted.

    And if the manufacturers don't get their devices certified with anything other than their weak default antenna, you still won't be legally allowed to use anything stronger than their default. This will vary by manufacturer -- Linksys might want to sell powerful upgrade antennas to its users, so it will get its equipment certified with a really powerful antenna. Apple, on the other hand, probably has no plans to sell replacement antennas for its Airport devices and will only get certification for its standard antenna.

    • Re:illegal antennas are still illegal (Score:4, Informative)

      by John Whitley ( 6067 ) on Friday July 23, 2004 @03:50PM (#9782922) Homepage
      Apple, on the other hand, probably has no plans to sell replacement antennas for its Airport devices and will only get certification for its standard antenna.

      Perhaps a poor example, since all current Airport Extreme models have an external antenna connector...

      • Perhaps a poor example, since all current Airport Extreme models have an external antenna connector...

        Apparently, it is still up to Apple to certify the device for use with an external antenna. Just because it is there, doesn't mean it is legal to use it for an antenna with a gain higher than what Apple certified it with. I'm not even sure if there is a way to get a third party to certify the AE with an antenna.
    • I think you make my point, though: it's better to be in compliance than out of it. If Linksys recertifies its gear with high-gain antennas, then it will be MUCH easier for community networks and others to use perfectly legal antennas instead of what are clearly illegal ones.

      It just makes it easier to be legit and thus avoid the potential for prosecution.

  • Ham on 2.4gh (Score:4, Informative)

    by Faith_Healer ( 690508 ) on Friday July 23, 2004 @03:24PM (#9782613) Homepage
    If any one wants to use highpower 802.11 on 2.4gh and use huge wave guide antenas with that high power equipment then all they have to do is get a ham lisense. With the introductory lisense you can use super high power out put transmitters and realy high gain antenas compared to the comercialy avable stuff. How would you like 100 wats PEP on your access point? The only thing is you cant use it for comercial purposes only personal uses. If you get the liscense you also get access to other bands and you can legaly build your own radio equipment. Its not hard to get the lisence either and there are probaly tons of hams in your area to help you get into and promote radio hobbies like packet radio. Check out www.arrl.org, or www.qrz.com if you need some more information.
    • Quick note. Hams are subject to a number of rules about content. Encryption is not allowed. Neither is profanity, or any content that could count as business related.
      A ham using an unmodified 802.11 device uses it under part 15 of the FCC rules and can send whatever they want over it. If you get a ham license and boost the power of your 802.11 device, everything you send over that wireless link is subject to the additional rules that govern the ham bands.
      In other words, using your ham license to legally
  • Why would the FCC worry about the gain on these antennas? The transmitter can only pump out so much juice, and as far as I know the gain of the antenna can't boost the TX power (only direct it), and only the amount to power that is RX'ed is boosted. Someone please explain why High Gain antennas are/were evil to the FCC?

    • Re:Question... (Score:4, Informative)

      by Deadstick ( 535032 ) on Friday July 23, 2004 @03:39PM (#9782785)
      The point of the power limitation is to restrict the signal strength, and thereby reduce interference.

      So Tom, Dick and Harry have houses in a row. If each one has nondirectional antennae on his home network, none of them receives network packets coming from another's house. But if Tom and Harry set up directional antennae so they can network together, Dick will receive packets from both Tom and Harry, and his throughput will go down.

      rj

    • Re:Question... (Score:4, Informative)

      by plcurechax ( 247883 ) on Friday July 23, 2004 @03:54PM (#9782983) Homepage
      Why would the FCC worry about the gain on these antennas?

      Because Part 15 for license-free (or license-exempt I can't remember which term they use officially) limited the total effective raditated power (ERP) to 4W, and a limit of 1W transmitter. So you can use a up to a 1W transmitter and a 6db gain antenna and remain within the Part 15 limits, or a lower power transmitter (typically 100-250mW with WiFi) and a higher gain antenna.

      Someone please explain why High Gain antennas are/were evil to the FCC?

      Because license-free devices have no protection and are suppose not to interefere with licensed "services" (official term) in the same frequency band (2.4 GHz has several users including Industrial, Scientific and Medical usage, and I believe some satellite downlinks are also in 2.4 GHz).

      Modified devices may create intereference on harmonics (normally non-approved amplifers are most common cause of harmonics). The limited gain of antennas limits intereference between license-free devices and licensed devices.
    • The transmitter can only pump out so much juice, and as far as I know the gain of the antenna can't boost the TX power (only direct it)

      The thing that matters physically is not the total power but the power density (i.e., the amount of energy passing through a given surface area per unit time). Think of power as force, and power density as pressure. Imagine a 15 pound textbook sitting on your chest. Not so bad, is it? Now, imagine pressing the tip of a pencil into your arm with the weight of that same 15

  • WiFi Fiction (Score:2, Funny)

    by Anonymous Coward
    JULES -- okay now, tell me about the WiFi bars?

    VINCENT What so you want to know?

    JULES Well, WiFi is legal there, right?

    VINCENT Yeah, it's legal, but is ain't a hundred percent legal. I mean you can't walk into a restaurant, take out your laptop, and start downloadin' away. You're only supposed to download in your home or certain designated places.

    JULES Those are WiFi bars?

    VINCENT Yeah, it breaks down like this: it's legal to buy it, it's legal to own it and, if you're the proprietor of a WiFi bar, it's
  • While I'm confused by the FCC actually maybe doing something sensical, does this maybe make it easier to prosecute if you *aren't* using an antenna from the "approved" list, i.e. the pringles can?

    I mean, sure, if you can show your antenna is lower-gain than the approved one, no problem... but then, why would you have switched to your lower-gain one?

    No, I didn't RTFA. Anything with FCC in the title makes my head hurt.

    • Well, I can almost understand not RTFAing, but you didn't even correctly RTFBlurb.

      "a manufacturer can certify their hardware with the highest gain legal antennas of each type (yagi, omni, etc.) and then end-users can swap in antennas of equal or lesser signal characteristics."

      The manufacturer will certify a product with the highest legal antenna of each type, then sell you the product with their normal low-gain antenna. As a manufacturer, would you rather sell a product with a $0.05 antenna that can on
      • oh of course, I understood that... the little attached antenna on the wifi basestations certainly aren't the best, and never will be.

        My point/question is that if you aren't buying the "approved" high-gain antenna, or are using one of a unknown characteristics, aren't you more obviously in violation of FCC rules, making your prosecution a bit easier?

        Though, if you're using a pringles can covered in foil, I guess you're pretty obviously in violation anyway...

        • OK, I see your point now. I think you are in the same boat as me with respect to our knowledge of antenna designs. I'll see if I can get my friend to reply to you and give better info than I can.

          The way I understand it is that certain antenna designs have theoretical maximum gains and ERPs. A Yagi made in the best possible way with the best possible components will give you this gain and ERP. The company would then certify for THAT design (or as close to it as possible if they have to do real-world tes
          • This is a mixed bag-- you can't certify an "ideal antenna design," because ideal antennas are only that for a specific frequency. WiFi covers a range of frequencies in the 2.4GHz ballpark.

            It would be possible to build an antenna of the same design type as a certified one, but tuned so that its gain is outside of the legal bounds on a particular channel or two. This could be as simple as making an antenna more directional, or by changing the distance between the little cross-pieces on a yagi. So even tho

  • Ok (Score:2)

    by afidel ( 530433 )
    so they struck 15C 15.204(c) [akamaitech.net] which is the only provision which might even potentially make it illegal to use an additional antenna (all other regulations are about sale, distribution, and marketing). Besides which 15C 15.23(b) [akamaitech.net] already hinted that you could build/modify your own equipment so long as you made a good faith effort not to interfere.

  • ...a manufacturer can certify their hardware with the highest gain legal antennas of each type (yagi, omni, etc.) and then end-users can swap in antennas of equal or lesser signal characteristics...

    This means that the listed performance characteristics (coverage pattern and gain, primarily) for access points will become basically useless while shopping for AP's because the numbers that the manufacturer uses in their specifications will represent "best case" antennas. At microwave frequencies, even t

  • Pringles can antennas (Score:4, Informative)

    by SKPhoton ( 683703 ) on Friday July 23, 2004 @04:18PM (#9783355) Homepage
    The pringles can antennas work really well. I've built two of them. There's plenty of really [oreillynet.com] good [turnpoint.net] guides [netscum.com] on how to make the antennas and how they work.
  • The guidelines say its ok, as long as the antenna isnt shaped like a breast.
  • Well I didn't know that. I should get a switch blade and not assemble it.

    I should also order an AK-47 kit [cheaperthandirt.com] and not order the missing receiver through some place else or have some manufacture [emachineshop.com] a custom one for me cheaply. (yes you too can have an fully automatic illegal assult weapon for under $200, as long as you don't assemble it).

    Funny how the same place also carries high capacity magazines, ammo and drums for that particular fire arm. but you're not suppose to have any of this stuff. (Sorry won't ship th

Slashdot Top Deals

The use of money is all the advantage there is to having money. -- B. Franklin

Close