Cell / mobile phone signal relay.

I work in a building with a metal roof that is also in a small valley. We have absolutely no reception inside the building. Outside we have about 4 to 5 bars, inside there are none. Maybe one if you are near a window. The building is mainly one large open space on the side.

I was wondering if it might be possible to passively "pipe in" cell phone reception. I was thinking of a large antenna on the roof that would be connected to a smaller antenna affixed to the middle of the ceiling of the main room. I know the antennas would need to be tuned to the correct bandwidths and I would need a little help with that. (Our carrier is Verizon in the USA btw). Would this sort of setup be feasible?

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Jarun (author) 2 years ago

I want to reiterate and stress that I am looking for a PASSIVE solution. Some thing that will allow passage of a signal into essentially a faraday cage (the size of a building because it actually is one)


A large in antenna outside the cage attached to a cable going inside the cage attached to another antenna of the same size or smaller. Would this setup allow signal to pass from the outside antenna through the cable to the inside antenna and broadcast with enough to allow a device near the inside antenna to pick it up? No matter how weak it might be on the inside, it would be better than nothing.

The main issue with making something like this, especially if you are in the US, is regulation. Any device that emits radiation (including, but not limited to RF, light, sound etc) is regulated, and in some cases, heavily. This is why any commercially available products on the market are so expensive, not to mention the potential use of someone with malicious intent gets a hold of one, they can be easily used to intercept and/or modify the data in its raw form (think of things like the "stingray" that is reportedly used by several government agencies.) A different approach you may look into, is most phones have an external antenna adapter under the battery cover or under some small cover. You can get these antennas fairly cheaply, along with a battery cover to attach it to, and greatly increase your range, even within FCC regulations. Do be aware however, there have been issues with the internal antenna being disabled and not re-enabling itself after an external antenna is disconnected, on certain phones. In this situation, research is king. I dont know about you, but I dont have several grand to shell out for a cell signal repeater just to get some better signal, plus going outdoors every once and a while (even if to just check your phone) is always good for people :)

There are systems available to "relay" cell signals from a weak source to another transmitting antenna.

Only problem is that the cheap one only cater for a single phone but neve for multiple connections.

http://www.verizonwireless.com/accessories/signal-...

For some reason I only get a blank page for their signal boosters but if you contact them and explain the situation they might actually give you a good discount.

Jarun (author)  Downunder35m2 years ago

Thanks for your reply. Those are all repeaters / powered options. And yes we would have to have one for each phone and it would likely tie it down to one spot. From what I understand they are not much good in this instance because the roof is absorbing or warping the signal. It would also do much the same to anything we transmit from under it.. What I am hoping to build is sort of a channel for the signal so it may penetrate our roof.

I am also very curious if my proposed idea of a passive relay is at all feasable.

Not entirely true...

For example some, like this one:

http://www.verizonwireless.com/accessories/samsung...

Cover a lot of area and support up to six simulatanous calls.

Plus in areas with no reception at all they can run over the network.

I am outside the US, but we have similar devices here in AU.

I guess you best option is talk to Verizon directly to find out what solution is the best for you.

The above would still be good if you have reception indoors, like near a window, for no reception at all you can get devices with outdoor antennas doing the same thing.

I have even seen them mounted on roof tops to cover the entire ground of bigger companies while at the same time enabling wireless communication through the company network.