I’ve read about the problem of cell phones in prison for the past year or so and I’m not sure why this is such a difficult problem to solve. If prison officials don’t want prisoners to access the outside world, and the FCC won’t let them set up jammers, why not do the next best thing? Why not set up a small, low-power cell site in the prison itself, and lock it down?
Any phones inside the prison will automatically register themselves with the bogus cell site because the local site will have a stronger signal inside the prison. Then the prohibited cell phones could be easily identified, flagging them for later confiscation. Also, the repeater site could either monitor any transmissions from the prisoner’s phones, or block those transmissions completely. All of this would be playing by the FCC’s rules and the cost would be less than $10,000 per prison.
Why hasn’t anyone tried this yet?
Update 1:27 PM: Looks like several states are implementing the “managed access” solution I’ve suggested. (Thanks, Guus!)
(1) I doubt it would work this way, because the phones would not lock on to the “strongest signal”. They would prefer their own carrier’s networks.
(2) I doubt that this is “playing by the FCC’s rules”, since it would affect anyone even driving by the prison. It’s been a long time since I was in that industry, but the FCC has some strict guidelines on who can operate in that licensed spectrum, and what equipment they can use.
That being said, I am also surprised that there is such a problem with phones in prisons. I bet I would be surprised by a lot of things that go on inside prisons.
Thanks for the insight, Alan. Yes, I meant to imply that a phone would register with its network, but the strongest cell would likely be used.
Read the report to Congress [PDF] as it talks about exactly this plan (“managed access”) as being preferred by the carriers. Carriers are also licensing vendors to use their frequencies for this purpose.
As for keeping a managed access signal inside prison walls, there are easy ways of effecting Faraday shielding. Even without going the Faraday route, an antenna placed near the (prison) cells wouldn’t have kick out a very strong signal to become the preferred cell site of a contraband phone, depending on where the nearest outside tower is.