CellAntenna Still Plugging Away on Cell Phone Jamming — And Why They Must Not Succeed.

I’ve been following the adventures of CellAntenna, the company that wants to sell cellphone jamming devices in the U.S., for awhile now. As lots of folks would love to jam cell phones — from hotels that hate losing the revenue from charging for use of their phones to theater venues that want customers to enjoy the show to schools trying to tamp down on texting in class — you would think there would be lots of these jammers on the market. The problem, of course, is that Section 333 of the Communications Act (47 U.S.C. 333) makes cell phone jamming illegal. Just in case anyone missed this rather straightforward statutory prohibition, the FCC officially clarified that Section 333 means “no cell phone jammers” in 2005.

Enter CellAnntenna, determined to sell cell phone jammers legally. If you are going to develop a legal on something illegal, you either need something real clever (like magic cellphone blocking nanopaint), or a strategy for changing the law coupled with the sort of stubbornness that does not mind slamming into a brick wall 99 times because you might dent it on the hundreth time. CellAntenna has apparently followed this later strategy — and may be making some headway.

CellAntenna initially tried to get courts to declare Section 333 unconstitutional. So far as I can tell, that’s going nowhere. Next, and far more successfully, CellAntenna has recruited prisons to push the idea that only cellphone jammers can resolve the problem that prison security sucks rocks. This has prompted a bill to create a “prison waiver” exception to Section 333 (House version here) and a raft of credulous stories like this one that prefer to ask “isn’t it awful that we can’t jam cell phones” rather than ask “what the $#@! do you mean we can’t secure our ‘maximum security’ prisons?”

I explore the issues, and why I think creating an exception to Sec. 333 would be a big mistake, below . . . .

If the experience with wireless microphones proliferating all over the place teaches us anything, it’s that once a technology gets sold at Radio Shack (or equivalent) it will get used by everyone. Which, I uncharitably suspect, is part of CellAntenna’s business plan. Prisons, after all, are a fairly small market. But if they can get cell phone jammers approved for a legal use, odds are good they will either keep pushing to expand the eligible pool or quietly allow a “gray market” to proliferate.

Even assuming good faith on the part of CellAntenna to limit availability of the devices, this interview in Ars Technica of CTIA’s Chris Guttman-McCabe highlights the problem of trying to limit this to prisons. I’m suspicious of permitting jamming as a general rule. When we add to this the likelihood of spillover effects, I get really nervous about creating an exception to the no jamming rule — even for prison security.

(I will add that the high price of landline phone calls in prisons (as noted in the interview) is an injustice that impacts the families of prisoners and cuts against everything we know about the importance of maintaining family relationships to reduce recidivism. But that is a topic for another post.)

Guttman-McCabe also makes another strong point by observing that cell phone smuggling involves inside help. Even worse than no security measures are bad/ineffective security measures. Although he doesn’t press this hard enough, I think the point is critical. If gangs in prisons can bribe/intimidate guards to help them smuggle cell phones and other contraband, it can’t be that hard to turn jammers off or bring prisoners to areas left clear of the jammer coverage (for example, areas left clear for use by guards).

Finally, from a policy perspective, setting the precedent that we should have waivers of Section 333 to allow blocking for “good reasons” is a very bad idea because I can always think of a reason why I deserve a waiver. Lots of people have security concerns about cell phone hacking. Should they be allowed to have jammers? Should schools have jammers to prevent cheating and maintain order in class rooms? What about theaters?

While a fair number of folk will probably think “good idea, and add my favorite restaurant to the list,” we should consider the negative impacts of such a scheme. First, for better or worse, lots of people are absolutely dependent on being in contact 24/7. If cell phone jammers proliferate, we are going to see an accumulation of stories about heart surgeons or parents leaving their children with sitters not getting critical messages in time because they did not know they were in a jamming zone. There is also the impact on public safety and data services. A device blocking cell phone reception in the 700 MHz, 800 MHz and 900 MHz bands available to AT&T and VZ is likely to have impact on all the other services in this extremely crowded band. After all, jamming devices are not smart devices designed to protect adjacent services — they are screaming loud emitters designed to block communication.

Bottom line: we have a real problem with prisoners getting access to cell phones illegally. Legalizing cell phone jammers, even for limited purposes, has very real costs for our communication system. We have had an absolute ban on deliberately interfering with someone else’s wireless transmission for more than 75 years that has shaped our communications infrastructure. To overturn that ban — however limited the exemption and however noble the cause — represents a fundamental shift in policy that takes us in a direction we really don’t want to go. That might be worth it if it solved the actual problem — but it doesn’t. Instead, we will open up the door to a new world in which we have legally available and therefore — if the history of wireless microphones and other such services teaches us anything — widely available. Worse, this will not only interfere with cell phone communication on which we have grown so dependent, but is also likely to interfere with traffic in the adjacent bands.

Finally, I find it particularly informative that the origin of this extraordinarily bad idea, and the energy giving it its current momentum, comes from a private company cynically manipulating the prison situation and the press for the benefit of its bottom line. I would find that obnoxious (but hardly unusual) if it didn’t impose costs on the rest of us. But I really have a problem with screwing up 75 years of spectrum policy solely to benefit CellAntenna’s bottom line.

Stay tuned . . . .


  1. Oh, will I have fun with this. I will call the <strke>lackeys</strike> critters and point out their idiocy.

    At work there is a big todo about blackberries not working in all of metro.

  2. Great points, but I worry that this is a classic example of a small-but-very-interested party screwing over the vast only-slightly-interested majority. I.e., nearly impossible to stop given our political system. Maybe wireless carriers should care about this, but I suspect that my missing an emergency call would affect their bottom line not at all.

  3. Jess, you are right — unless someone in the Fourth Estate starts exposing this and the supporters of the bill start getting embarrassing questions about “we have drug dealers getting shrimp scampi and ordering assassinations and you think the problem is we don’t have cell phone jammers?”

    For the life of me, I do not know why the reaction in Congress is not “we need a hearing on why our maximum security prisons are luxury hotels for drug dealers, with prison guards apparently doubling as waiters and concierges.

    What is idiotic is that I, sitting here, can devise means to address this issue available now — starting with remote universal surveillance so that any attempt to bribe/threaten/otherwise suborn a prison guard is detected by anonymous (and therefor unbribable and not initimdatable) observes using key word and visual recognition software. the behavior is instantly reported and discipline is carried out by anonymous, not bribable and not intimidatable teams brought in for the occasion. This would require an investment of money — but it would be worth it to have our prisons actually be prisons again.

  4. It has 38 sponsors, and a hasty look suggests none of them are members of the majority party. Is there a real chance that this will be reported out of committee, or is it a chance for Michelle Bachmann and her friends to run a fundraiser among their fellow loonies?

  5. Harold,

    I guess I agree with you, on the “nose under the camel tent” reasoning. And also on the engineering point that jammers are blunt instruments.

    On the other hand, I’m not much convinced by your “Oh noes! Surgeons won’t get calls from emergency rooms! Mommies and Daddies won’t get calls from babysitters!” and “this would be a departure from all precedent” arguments.

    Cell phones didn’t exist in 1920, ya know.

    I don’t have a problem with the idea of there being places where cell phones just don’t work (prisons being but one example, as you point out). Cell phones mostly don’t work in the Adirondack Park, and I say, keep it that way. If that cramps your style because you need to be reachable 24/7, there’s an easy and obvious solution to that problem. (Patient: Doctor! Doctor! it hurts when I do this! (pounds fist into side of head.) Doctor: Well, don’t do that.) Same goes for restaurants, churches, synagogues, theatres, etc.

    If the same result can be achieved by nanopaint, so much the better. I might be able to be convinced on this point, (i.e. that cell blocking paint is a Bad Idea), but at first blush I don’t have a problem with it.

    (Aside: I have a friend who travels with a universal “off” single-button remote control, which he uses to create Television Free zones in airports. I frankly don’t have a problem with that. If the airports provided TV free zones, that would be a different story. But they don’t, generally speaking.)

    In the name of caution, I’ll ask my representative to vote against this.

    But I’m not entirely convinced by your reasoning. I think maybe I’ll do my own post on this & related topics. If I can get myself organized enough to do so.

  6. Howard Melamed

    Interesting perspective, but you sort of got this whole thing completely wrong.

    First, we are not interested in selling jamming equipment to the public. In fact we want these laws strengthened and out of the hands of the FCC who for the most part lack the ability to enforce the current laws. Right now, you can buy jamming equipment on the internet and get it delivered to your door…without our help, or the US Customer service, or even FEDEX who knowingly deliver the product.

    What we want is what is already legal. That is to block cell phones in prisons, and to allow our bomb squads the right to use jamming equipment if they find a remote controlled bomb! What is wrong with that?

    It is legal to jam in a prison. That may surprise you , since we are going around the country in trying to get our government to change the law. Section 333 of the 1934 communications act deals with interfering with RF Communication. It clearly states that only the Feds are allowed and the local and state governments are not. However, the question is, are we talking about interfering with legal communication or illegal communication?

    There is a big difference and here is what the CTIA lobby group has poisoned our minds : It is illegal to interfere with legal communication. However the law does not deal with illegal communication.

    Here is the example: If I have a LEGAL radio station, and a pirate radio station sets itself up near me, and start broadcasting at the same frequency but at a lower power, I am interfering with the illegal broadcast. In the application of the law as the FCC would have us believe, even a legal radio station would be sanctioned under 333. Clearly that is ridiculous, and clearly interfering with an illegal signal is not an offense.

    In prisons, it is illegal to own a cell phone or use it. In most cases even the guards are not allowed to use them. Jamming of an illegal cell phone, is not violating any law. However if the jamming signal knocks out the surrounding community, even one phone, then it is in violation of the act.

    Our equipment only jams the prison. We proved this in South Carolina. It does not affect public safety frequnecies. We can jam a phone, a room, a building. We are that good. And there are other companies like ours that can do the same.

    The CTIA and the FCC knows this. Yet they continue to block our USA technology. The only reason is that the cellular carriers make 4-5 billion a year on selling service to the inmates.

    They want you and I to pay for increase security measures to try to stop the pandemic, which worldwide has proven to be ineffective.

    For the most part, the problem is that the public does not know all the facts. Hopefully, now that you have them, you may change your mind in your opinion on us and the issues.

    Howard Melamed
    CellAntenna Corp

  7. Howard:

    Your interpretation of the law is certainly interesting. If true, why do we need a bill? And why has the FCC turned down your STA (special temporary authority) application?

    Further, under 47 USC 302a, it is illegal to market, sell or ship devices capable of causing harmful interference that do not comply with FCC regulations. 47 CFR 15.1 says that any intentional or unintentional radiator not licensed under Sec. 301 needs a Part 15 certification. You got a Part 15 certification for a jammer? You operating pursuant to some sort of authorization? If so, I’m curious why you need legislation.

  8. Strictly from an engineering perspective, any RF signal can be filtered and controlled on either a bandspread or channelized basis (or both) from the signal origin. Thus a jammer could be deployed blocking just 700MHz AWS, 800MHz cellular and ESMR, and 1.8/1.9GHz PCS services WITHOUT affecting adjacent channel services, namely public safety. It’s simply a question of additional monies when deploying the system and proper engineering talent.

    FWIW, the DOD does this on a regular basis.

  9. Certification of the device is not possible since the FCC does not consider the jammer to be legal. However, on one hand you are dealing with whether or not you are allowed to interfere with an ILLEGAL signal. Once you get over this and understand that 333 has no bearing on illegal signals, the next question is about the equipment being licensed.

    We can stop cell phones in prisons using legal equipment that is not jamming and has the certifications. It is quite expensive. However jammers can do it for 25% of the cost. The FCC need only rule on a method to certify the equipment.

    However we can’t even get to first base with the FCC to come off the high horse on the “is it against the law to stop an illegal signal” which is paramount to saying “ Is it against the law to stop a crime from being committed” …. So can you imagine asking for provisions to actually certify jammers 🙂

    Our legal interpretation is that it is legal to stop an illegal signal, so long as you do not stop a legal signal. No law is needed.

    Henry’s comments are correct. Proper engineering talent is all that is needed to makes sure we do not jam public safety and do not jam legal communication. That is precisely what we do. Check out part of the presentation and the test itself at : http://www.youtube.com/watc

  10. Howard,

    C’mon. If someone sets up an illegal pirate radio station in my neighborhood, that fact does not give me (another non-licensee) permission to jam it. What you are proposing is tantamount to THAT example, not the example of a licensee continuing to broadcast while jamming is present.

    Your interests are pretty clear. Your website still hosts http://cellantenna.co.uk/CJ… which offers to export jamming equipment to anybody outside of the USA, not just government authorities.

    By the way, your newest rouse of trying to get Law Enforcement agencies to buy jammers for bomb squads is laughable. The last thing a bomb squad is going to do is throw RF at any device, regardless of the trigger.

    As for proper engineering talent being the only thing that is needed, no amount of talent will completely defeat physics and the absorbency of the different building materials. Trying to keep a jammer’s RF from escaping to the outside while keeping it plentiful on the inside requires turning the prison into a Faraday cage — which, by the way, would block signals without jamming them. Another way, which also works, is to keep cell phones out of prison.

  11. “As for proper engineering talent being the only thing that is needed, no amount of talent will completely defeat physics and the absorbency of the different building materials.”

    This is where talented engineers earn their pay; absorbency and reflection is materials and frequency dependent and the building structure can in fact be used to advantage. Further, with the proper selection and deployment of radiators (e.g. directional antennas and radiating coax), transmitter power levels and free space path loss, a relatively contained system is absolutely possible.

    Will the the system cover 100% of the target area and 0% of the non-target area? Of course not. Engineering is compromise and each installation must be addressed as a unique design. It may also turn out not to be cost effective to do such a precise installation.
    “The last thing a bomb squad is going to do is throw RF at any device, regardless of the trigger.”

    There’s a distinct difference between creating a broadband noise floor increase or false control channel and targeting a specific device with RF energy. The area wide “jamming” of cellular and PCS services is a standard tactic for both the military and USSS, has been for several years and with much success.

  12. Yes, it is a standard military tactic, when you don’t give a crap about impact on the enemy and have your own communications on other frequencies so that you don’t screw over yourself.

    But let me see if I understand your argument:

    1. Using smart radios to sense available spectrum, coupled with a database of vacant channels, is insufficient to protect wireless microphones and other TV bad equipment.

    2. But jammers blocking the 700 MHz band when it comes online are no problem.

  13. Two entirely different engineering issues.

    With TVBDs, the challenge is to sense the RF environment and analyze it to a high degree of accuracy and reliability: Something that currently takes near one thousand dollar devices to accomplish. There’s insufficient space and monies (at least given current technological capabilities) to accomplish this (which your camp has presumably since come to realize as you’re now all clamoring for the FCC to abandon spectrum sensing after your previous claims of its virtues). The idea behind TVBDs is to be small, cheap and quickly mass producible, right?

    Jamming would involve conditioning the originating signal with far less consideration to size, cost and time to deployment. A properly filtered and conditioned jamming deployment requires a bit of space (several dozen cubic feet at least for the filters, di- and triplexers, splitters, combiners, etc.) and does not come inexpensively or quickly. And yes, if engineered and deployed properly, one could “jam” for the most part upper 700MHz blocks A, B and C without creating interference to adjacent D block or the 700MHz PS bands.

    BTW, the military’s jamming practices are not only a scorched earth strategy; they do take a more calculated approach, as does the USSS who often have the DoD deploy a cellular/PCS jamming system in the middle of metropolitan areas without affecting local 800MHz PS (though they do seem to affect the lower end of the 900MHz ISM – 902-928MHz – band).

  14. I totally disagree. With the right technology prison facilities can be cell phone jammed

  15. as a teacher in Los Angeles, I would really appreciate not having to spend all day everyday telling kids to put up their cellphones…if I could jam the signal then all my problems would be solved.
    FAM at LAUSD

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