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Boosting Cell Phone Signals in Strange Places?
hedgemage asks: "I work at a retirement home and we have trouble with the cell phones that our nursing and maintenance staff use. The problem is that our nursing home area is built into a lower level that was originally constructed as a fallout shelter in 1960. There's a lot of solid concrete in the walls and ceiling. We have paid out tens of thousands to try and get an on-site mobile to work using NEC Dterm PSII phones, but they have proven absolutely unreliable (not just in the bomb shelter but throughout the campus) and the only solution our telecom provider has is to install several thousand dollars more in transceivers. If we could use ordinary cell phones, it would be ideal for everyone. Is there an off-the-shelf solution that could boost regular cellular signals in our bomb shelter?"
The problem is that our nursing home area is built into a lower level that was originally constructed as a fallout shelter in 1960. There's a lot of solid concrete in the walls and ceiling.
Propose management to relocate the retirement home to a nicer place with, for example, windows and sunlight. Jesus man, who the hell make older folks live in a former fallout shelter? It's really sad. Tell me where it is so I know never to send my mother there...
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Theyre called cell phone repeaters. They are expensive ~ $300 - $100 and may run afoul of the FCC. If the cells are for job related communication, why not get some walkie-talkies?
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I like how this page showed up with some answers before anyone posted.
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Does exactly what it says on the tin. Used in tunnels in Europe for cell phone coverage.
Just use wifi phones and put wifi repeaters on the campus.
It's not a great solution but it's cheap and simple.
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This is what I was going to propose as well. Passive is the way to go, simply because you should be able to do this without running afoul of the FCC.
Here are a few more details to help with this:
(1) Make sure your service provider is one of the cellular carriers in the 800 mhz band. While this will work for both cellular and pcs frequency bands, generally speaking the 800 mhz will have a slight advantage for penetration within buildings. At this point you will probably need every edge you can get.
(2) Locate the closest cell tower that provides coverage to your location.
(3) Get a directional high-gain antenna and mount it outside pointing at the cell tower.
(4) Determine where the inside antenna will be placed, and then figure out the beam pattern/width you need. For example, if you put it in the center of your area, an omni antenna will probably work, if you put it on one end, a directional antenna with the main lobe pointing inside the area.
(5) Connect the two with low-loss coax. You may need to use 5/8, 7/8, or larger coax depending on the length of the run from the internal antenna to the external antenna.
You are going to want antennas that are tuned to cover the entire range of the cellular band, not just tx only or rx only antennas.
If the passive system does not work, contact the wireless phone provider you are using, and ask them about setting up a micro-cell, repeater, or enhancer to cover your area. You may need to volunteer to pay for some or all of the physical equipment and provide electricity for it. Since they are putting in the equipment, you still shouldn't have any problems with the FCC.
I don't know how well this type of passive antenna configuration will work. I've seen mixed results in the past when I was playing around with things like this. It all depends on how much boost you really need to make things work. If you have a budget to make this work, your best bet might be a powered system put in with help from your wireless provider.
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Get one of these.
http://www.jdteck.com/repeaters-consumer.htm
Yea they cost a few hundred bucks, but they look really simple.
Directional antennas on a rooftop that points directly to the nearest celltower(s).
Omnidirectional antennas indoors at strategic location, one indoor antenna per external antenna.
Use low-loss cabling between the antennas. The cabling and installation of the cables may be the most expensive issue. As this is a completely passive solution you shouldn't have any trouble with FCC.
There are certainly disadvantages with this solution too, and it may not work or be feasible for your situation.
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You may be making things more complicated than they have to be by insisting on the absolute newest technology. Sometimes an older technology fits the situation better. For instance, if you just run some land lines down there, you can install regular old cordless phones. With the base-stations and the phones both in the sheltered area together, reception should be largely unaffected by the super-thick walls, and Bob is your uncle.
Cut that out, or I will ship you to Norilsk in a box.
Dunno if it actually does anything but there used to be such mode that would supposedly use more battery to produce stronger signal. In some phones you activate it with *3370# (phone will switch off) and disable it wih #3370#.
Wilson Electronics has some way-cool products as far as cell phone antennae & signal boosters are concerned: parent: They are expensive ~ $300 - $100
I assume you meant "$300 - $1000", but for a communications device that is meant to be used by tens [and possibly hundreds] of people, in a business setting, that strikes me as decidedly inexpensive.
Or maybe I just haven't been keeping up with telecomm prices these days [isn't the Apple iPhone supposed to start at $499.99?].
PS: The real "expense" will be the time you invest on ladders above hung ceilings, or in attics, or crawling around basement crawl spaces, pulling RG-6 coaxial cable.
[Or paying the illegal aliens to do it for you...]
Talk to the cellphone carrier(s) about this -- I know Telus in Canada had a program where they would install RF equipment (boosters or micro-cells, I'm not sure) for use in warehouses, etc. (though of course I can't find the page right now!). If your volume is small, you might pay, but if you have enough users they might put in a micro-cell on their dime. If they are aware of the business opportunity they will probably figure out how to accomodate you.
as a one-time employee of a smaller provider, and now as a bigger provider, i suggest that you first see if there are any smaller providers in your area willing to set up a repeater for you in/on your building. if a customer made enough noise, and had a big enough account (tens of phones, maybe?) we could be swayed into helping out with signal propogation. if you start talking about using repeaters on your own, depending on the law in your area, you may force their hand, as an improperly tuned network could be degraded significantly by such a device (handoffs can act strangely, for instance) also, using a repeater can have negative effects on positioning technology, if your provider is using a network-based e-911 solution. one last thing - if the signal in your area is bad outside of your building, and it's a large enough area, offer to house a site on your property. you never know where that could lead - you might boost your signal, and get some monthly cash flow to boot.
Ask Slashdot: Boosting Cell Phone Signals in Strange Places?
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OP here, thanks for the answers so far. I'm not a telecom expert, but I've been given this task, so I'm having to learn quick. We've been using some cheap PTT radios, but still have some dead areas with them (oddly enough different dead areas than cell phone reception). Unfortunately, the nursing staff need to be able to contact doctors, family, 911, etc. from any location, hence my search for a phone solution.
Also, the truly bunkered-in sections are our maintenance shop, break room, and storage, so while the residents get plenty of sunshine and fresh air, I don't. Typical geek stuck in the basement.
I got a catalog not long ago from Cyberguys and I remembered seeing just such a repeater in there. I have no idea about the quality of the repeater or of Cyberguys, so do some reasearch first. But if you're interested, they have this and this, either of which may work for you.
You ended your original comment by saying: If we could use ordinary cell phones, it would be ideal for everyone. Is there an off-the-shelf solution that could boost regular cellular signals in our bomb shelter?
Again, as I mentioned above, if you want to go the route of "regular cellular signals", then I'd take a long, hard look at Wilson Electronics [or an equivalent competitor]: The interconnections are made with RG-6 [RG-58] coaxial cable, which is possibly the easiest cable to work with known to mankind [let's face it, a retarded person could be taught to crimp F-Type connectors onto the end of RG-6 cable, and you can get the parts & tools at any Radio Shack, Lowes, or Home Depot in the United States], and their prices just strike me as eminently reasonable [given the functionality you'd be gaining by installing their equipment].
On the other hand, if you want to stick with PTT, then there are PTT amplifiers on the market, as well.
Propose management to relocate the retirement home to a nicer place with, for example, windows and sunlight. Jesus man, who the hell make older folks live in a former fallout shelter? It's really sad. Tell me where it is so I know never to send my mother there...
It's worth pointing out that you think these folks are cocksuckers for sticking old folks underground yet a Chinese person would probably say the same thing about you planning to ship your mother off when she gets to be difficult.
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OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
http://en.wikipedia.org/wiki/Cellular_repeater
My original title was, "Cell Phone Service in a Bomb Shelter" but I immagine that it was toned down by the /. staff for being a bit too explosive for the actual content.
Ditch the old NEC DTerm system, it's old legacy equipment that's expensive to maintain and provision. Instead, invest in cheaper phones and a better platform like Asterisk for your PBX and Linksys phones.
You can add in wireless access points at various points in your basement to allow for wireless voip phones like the UTStarcom, Zyxel, or others and you'll also potentially allow for wireless internet for the residents lucid enough still to use a computer.
For fax machines, use the Sipira SPA-2000 or SPA-3000 series. I'll assume you're using a fractional T1, ISDN, or POTS lines to connect to the public phone network, so use Digium hardware to connect it all.
It will be MUCH cheaper than maintaining the NEC systems, you get more functionality out of it, and you don't have to pay big bucks for cell phone providing.
IF YOU INSIST ON HAVING CELL PHONE CONNECTIVITY INSTEAD -
You can contact companies that provide small base-station repeaters that hook into a DSL or cable modem connection that will put out GSM signals for your phone connectivity. You may have to pay up front or not pay at all, depending on if you get a corporate cell account with the provider. T-Mobile does this. Not sure about other systems. Verizon, Cricket, and Sprint's coverage seems more successful with penetrating through to basements as they are based upon CDMA technology.
Someone above mentioned WiFi phones. I know of various wireless VOIP phones (i.e. from Skype) that could use a normal AP to broadcast. It'd save on minutes/ phone plans too. I'm not sure about the price range/ number of users you have, but it might be a viable option. My previous school was once an USAF base as well as fallout shelter, so I felt the pain of having little to no service. I often used Skype on my Pocket PC to dial out via our campus wireless. Hope this helps!
Learn this new buzzword: Femtocell
It was all the rage at the recent 3GSM trade show in Barcelona. I happen to work for a company developing such a product.
They're not ready for primetime today, and even if they were, your cellular operator would have to offer it as part of their service -- you couldn't use one independently. But in the next year or two, they will begin to be a commodity.
Sorry it won't help your problem *today* - but maybe it's a consolation that a product is being developed to meet your PARTICULAR problem directly!
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I recently completed the installation of a distributed antenna system in a new hospital building. 7 floors, 300 feet by 150 feet.
It works well. There is now excellent coverage throughout for cellular phones (specifically, 800MHz cellular A and B for Alltel and Verizon). There is also a separate, parallel system installed for the local public safety agencies 2-way radios, which really was the main point of the project. Adding more cellular carriers would be reasonably straight-forward at this point, now that the cabling and antennas are installed.
There's 4 cellular and 2 VHF antennas on each floor, with an additional smattering of each for the stairwells. These are all fed by 1/2" air-core plenum-rated coax, which itself is holy-fuck expensive, difficult to handle in a hospital environment without damaging it or yourself (400lb reels), and very tedious to install.
The installation was non-trivial, required several man-months of labor, and was hugely costly and difficult at all stages.
Does any of that sound familiar? It should. It's probably something very similar to what your NEC vendor was suggesting before it turned expensive.
No matter what you do, you're going to end up needing lots of antennas/transceivers scattered all over. And it's going to to be costly.
Think about it: A cell phone is just a radio. A NEC Dterm PSII system is just a radio. A radio that size which fits within FCC limits, and has battery life measured in hours instead of minutes, will have shit for output power. A low-powered radio will not penetrate concrete and steel very well. Using a cellular repeater system takes all of these propagation problems and antenna expenses, and adds to them the indignity of dropped calls, monthly bills, and additional reliance on outside services.
Re-evaluate your goals. You were probably already on the right by going with in-house system, though if your vendor is clueless and needs firing, you might look at using Spectralink as an alternative.
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I'd go with Wifi and get Wifi enabled cellphones (like T-Mobile has) that will enable you to place and receive calls via Wifi when it is available. It'll save you airtime charges too if you can use your own Wifi internally.
Or if you don't need cell capabilities and don't mind a bit crappier phones you can get Wifi phones for Skype and Vonage.
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Back when I was in college, I stuck a passive cellphone booster antenna on my window. It helped. You might be able to stick a passive cellphone antenna outside, and run a wire inside.
I hate to say this, but you can watch the movie "Panic Room" for a Hollywood example of what I described.
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