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A Private GSM Cell?
mr number two asks: "I live in the mountains and have poor GSM reception. I can buy an active repeater to boost signal strength in my home to good levels, but what I'd really like to do is have a private GSM picocell, such that at home I would be connected to my own PBX. Calls to my home phone number would ring through to my cell phone. I wouldn't have to worry about a home cordless phone (and 802.11 interference) and I'd have all my speed dialing / contacts info right there. There are many other benefits. Ignoring FCC licensing issues, is there a base station I can purchase which has a signalling interface that will interface to a small PBX?"
I've heard about cell phones that have a base station that plugs into your home phone line to give you access to both when at home... do those do the trick?
[This space for rent]
This looks like it might be helpful:
http://www.voip-info.org/wiki-VOIP+GSM+Gateways
The site www.voip-info.org itself looked promising during my brief visit....
I use vonage and have the simulring feature turned on to ring my cell at the same time- then I have my cell set to forward after a set time back to the main number- this is awesome because all my numbers now ring to all my phones and since vonage has free incoming calls and the cell doesn't, I can manage my time with both plans more easily. All calls also end up in the same voicemail box with the vonage account and then that emails the message to me so I never have to check it manually.
This system has worked amazingly well for me for the last couple months and it's eliminated all the issues I used to have with other landlines.
good luck!!!
Creationists are a lot like zombies. Slow, but powerful and numerous. And they all want to eat our brains.
Everything is available for a price.
On the other hand, I might suggest searching for a solution that does not ignore the rules. Rules for communication systems are (for the most part) fairly sane. The avoid pesky things such as cross talk, interference, etc. But hey, this is Slash, who really cares about that kind of thing ;)
-- www.WhereHaveIBeen.com
they seem to sell alot of different equipment. www.tessco.com
Si vis pacem, para bellum! For evil to succeed good men need only do nothing!
Don't waste your time.
The SIN card you have in your phone is tied to your provider. The provider paid millions/billions to license a GSM band in the US.
The technology that actually powers this is inhibitivly expensive. If you wanted to hack your own non-rules based GSM station, then you'll have to worry about the FCC and anyone else not liking you break the law.
It'd be more feasible to hack in a second antenna, talk circuit into your cell. I don't see it being easy even on bulky phones, but its possible.
Bye!
There's a lot of models that are similar to cell phones, and many have ranges of up to 30 miles.
Here's an example.
http://www.4cellular.com/cordless/
Googling for cordless phone long range returned a lot of results.
Cingular used to sell an item that did this exact thing. I'd start there.
-bZj
.sig
Sure. You can do what you want but the hardware is incredibly expensive and you'd need a license to operate as a telecoms provider which also is incredibly expensive. If you're looking for a way to reduce your cell phone bills then this isn't it.
Since you're going to be operating a transmitter it's not going to be too hard to find out where that rogue cell signal is coming from either.
Don't think that they won't notice because you're up in the moutains. People are employed to drive around with a pile equipement and do site surveys. There was an article with pics about it recently.
There are two options, either of which avoids the problem, either 900Mhz or 5Ghz (you weren't planning on deploying 802.11a were you ?)
Please tell me you didn't go out and buy the coolest phone a few years back in the 2.4Ghz range, and now aren't willing to "upgrade" to a 5Ghz phone.
I have mod points and I am not afraid to use them
Administering a wireless telecommunications switch, I have to ask: do you want a network of your own with no ties to other carriers, or just a cell?
If you're looking for a "just you" thing, good luck. The GSM standards are pretty easy to get your hands on, and with a little ingenuity, you could build a GSM switch. It's basically a few DBs and hardware interfaces. That's where things get tricky. GSM cells (which you could easily purchase for $100,000 (CDN)) need to communicate to the switch using a standardized protocol over T1. So you'd have to build THAT network stack over some sort of Frame-Relay-over-T1 interface (which are often rather expensive in and of themselves... also, good luck with Linux drivers...).
I left out the possibility of buying a GSM switch, because I doubt you'd be on Ask Slashdot if you had that kind of cash.
Now I know you said "apart from FCC regulations" or something, but that's what's going to kill you. GSM uses a 200KHz carrier (at least with the 800 and 900 MHz spectrum), and to put a site on the air with any sort of wattage in any location of any use (you are in rough terrain, no? So you'd put in on a peak... and spread your signal pretty far) without interfering with anyone else and without the FCC turning your way is going to be quite tricky.
Karma: Raspberry Kiwi
I have a problem with mosquitoes in my yard and I wonder if anyone has some good advice on the best kind of cannon and ammo I should get to shoot them down?
"It's a wonderful idea. But it doesn't work." -- Tad Danielewski
Gee, maybe searching Google could be useful.
Moderator hint: a comment is neither "Flamebait" nor "Troll" if it is true.
Ignoring FCC licensing issues
That could get you a 6 x 9 cell with a roommate.
Odds are you can't do anything yourself (FCC). However your provider can. Complain that you don't have strong service and they might put a new tower up in your area. Depending on how much money you have to spend they might allow you to connect your VOIP network.
Speak to a GSM network providor, like Vodaphone, Orange, O2 or something (to give UK examples). All of these providors will sell you a local cell unit, its a service they provide to companies with large sites or campuses, to use mobile phones instead of DECT phones across a wide area with automatic roaming off site. Calls within the same cell are free, with a annual rental, and calls off the local cell are charged at the standard airtime rate, and the bonus is that its just a normal mobile cell.
They already offer voip wireless basestations. The handsets are cell phones that automagically connect to your wifi when you're close enough, or connect through your cell carrier when you're away. Haven't seen anything like this in the US yet.
or else!
You can buy a small bts (base station transceiver) but that is only half of it. A bts is not designed to connect to the pstn. You would still need a GSM switch. Nortel makes what they call an e-cell which is meant for small buildings or inside malls. It costs $30,000. You are probably better off using WiFi or something like this.
Focusing on the original problem of "my cell phone gets bad reception in my house on the mountain" why not purchase a phone that is known for really good reception?
I bought a Nokia phone specifically for it's reception abilities, and I've had many people on the same wireless carrier that couldn't use their phone in places that I could.
Pick up a Nokia 6010 (basic phone) or 6230 (if you need all the features) and see if that fixes your problem.
Why fix the problem with a few hundred thousand dollars when a $100 solution would work.
Yagi Antenna [8 Elements] for Cell Phone Frequencies 806-896 Mhz / 870-960 Mhz
Availability: Usually ships the same business day.
all Cellular and GSM phones excluding PCS phones
US $49.95
Perhaps the answer was on slashdot the other day.
It was a cordless phone with something like a 10 mile range.
A blog I run for the wealth
I've also got Vonage simulring (love it), but the (Sprint/Treo600) mobile voicemail catches half the calls. How do I set the mobile account to send calls back to Vonage, without triggering another simulring, so the mobile voicemail never gets activated?
Also, any ideas on how to get Evolution to trigger a script, on receipt of the Vonage voicemail notification email, that sends an SMS to the Treo? With a speeddial hotbutton, or maybe a URL pointing to the Vonage WAV, closing that loop might put me into a single "Inbox" for all my messaging. What do you think?
Also, fuck the South!
--
make install -not war
I'm not sure, but I think there are some mobile phones that support a 900MHz standard called DECT. It basically a cordless phone standard that allows mobile phones to switch to (cheaper) land-line connections where available. I think.
"Hi! I live in a cave and have voices in my head telling me to kill people. I can pay my local prostitute to feign death, but what I'd really like to do is have a private basement pit, such that at home I would be able to do my murders undisturbed. I wouldn't have to worry about getting blood over my slacks, and I'd have all my brain-sized stewing pots right there. There are many other benefits. Ignoring local anti-murder laws, is there a particular type of teen hitch-hiker it's better to prey on?"
~~~~~ BigLig2? You mean there's another one of me?
Depending on geography and tower placement, you might be able to get a decent signal with a CDMA, PCS or AMPS phone...
Borrow phones from friends and make some test calls to see how they do. I wouldn't just go by number of bars.
Other possibility is to rig up a directional antennna and plug your phone into that (assuming it has an aux antenna jack). You won't be able to walk around the house and talk, but at least you'll have service.
T-Mobile has been rumored to offer in-home VoIP service in the fall of 2005. It wouldn't be legal for you to run your own "picocell" as the GSM frequencies are licensed, even in those picocells that the carriers deploy in malls and sporting events.
T-Mobile's rumored new service will utilize a new class of mobile phones which are GSM and WiFi hybrids. While you are away from home the handset works like a normal GSM phone. When you get home the handset switches to WiFi and connects calls using a wireless VoIP gateway that you connect to your high-speed internet connection. T-Mobile will bundle the hybrig GSM+WiFi mobile phone, the WiFi VoIP gateway device, and the VoIP service. To the mobile phone user the only thing they notice is that their T-Mobile phone works at home and they can finally drop that PSTN line.
This is in response to the overwhelming T-Mobile customers who tried to use number portability to switch their home phone numbers to T-Mobile and found that their mobile phone didn't work in their homes. Most of T-Mobile's spectrum is 1900 MHz which doesn't penetrate well into buildings. At the same time, T-Mobile (and the other carriers) were spending billions to acquire space in the 800 MHz spectrum to try to improve the situation but someone had the bright idea for T-Mobile to offer all-in-one GSM+VoIP service for much less money than building out their mobile GSM networks which already work really well outdoors.
I think it's a brilliant plan and it's much cheaper than giving everyone GSM repeaters at $500-$1200 per unit just so their mobile phones will work in the house (but never the basement)... of course the hybrid GSM+WiFi phone *will* work in the basement. It's simply brilliant.
Let's see if they really roll this service out.
Kriston
Umm, no, this device will not help you in the USA. Most GSM providers in the USA have GSM only in the ~1900 MHz range with some tiny amounts of GSM coverage in the ~850 MHz range. Cingular is desperately rushing to replace the analog cellular and digital TDMA networks in the ~850 MHz spectrum with GSM (their current phones already try to find a GSM signal there, but very few of them will work in analog, and only one of them will work in TDMA). Unfortunately for Cingular the FCC is mandating analog cellular to stay online at least until 2007 and TDMA to stay online even longer--its deadline recently extended to 2008.
T-Mobile has very localized ~850 MHz coverage in some markets where thousands of customers could get not service, like large residential areas and major highway interchanges. At least they're trying. This device you speak of won't work for T-Mobile, either.
Kris
Kriston
I know that a big nordic telecommunications company had a so called home base station developed a couple of years ago and has it ready in the cupboard. However they decided regulatory barriers to be too high and didn't launch it as a product.
In Korea, all your base are Only For Old People
hmmm, I'm working (Verizon, in N. Ca.) from a mountainside that's line of sight about 20 miles to the nearest cell tower; used to get only analog, now can get digital. If I go five hundred feet downhill, I'm in the shadow of the surrounding mountains and have no cell connection til I drive out past them. This is with just the handheld antenna.
I had been using an old analog-only dual-mode Nokia phone but recently switched to a Kyocera 6036 (Palm PDA plus tri-mode handset) so I've been looking for a signal booster myself that works for tri-mode. I note there are signal booster amplifiers, as well as external antennas, claimed to work for distant weak signal sites.
You do need to know exactly what kind of antenna works with your phone -- Kris obviously knows much more specifically what you need. Maybe you can get an exact specification and then search.
I'd be surprised if no external antenna is possible for you, if you can stand having to plug your phone in up on your mountain site.
Watch out for lightning storms though.
Maybe this one?
YAGI AND PANEL CELLULAR / PCS ANTENNAS
These low-cost antennas can improve your signal strength drastically. Installed on poles, the antenna points in the direction of the cellular tower. The antenna can be rotated on the pole until the connected cell phone obtains the maximum signal. These antennas can be combined with our signal booster amplifier product for maximum range.
Products include the CAY807 Yagi antenna, which features four-element Yagi with 7dB (9dBi) directional gain and can withstand 125mph winds, and the CAY1912 PCS panel antenna - a high quality, completely enclosed 11dB (13dBi) gain panel antenna for 1,850MHz to 1,990MHz.
Cell On Wheels. A number of companies sell them. The descriptions for some of them seem to be aimed at private networks.
Great strategy.
The CEO of Verizon said this very thing earlier this spring. T-Mobile has been saying this all along and recognizes the practicality of mobile phones in dwellings (it does not work) and is rumored to offer a real solution that will really work.
I don't know about where you live and work but when I walk outside my mobile phone gets nearly 100% signal compared to 10-50% signal inside. This is the same with my T-Mobile, Verizon, Cingular handsets, and two out of three use different towers in the areas I live and work.
Kriston
One thing to be careful of. These repeaters always use omnidirectional antennas (not uniderectional Yagis). If you are a CDMA customer (Verizon and Sprint in the USA) the provider will shut you down if you use a Yagi. The principle of CDMA is that all phones are balanced to the same signal strength. CDMA phones all transmit on the same frequencies at the same time and the tower will command your phone to reduce signal if it drowns out other customers. If your phone reduces its signal but is still too strong, the Verizon "Can you hear me now?" guy will find you and shut you down.
GSM is more forgiving to Yagi users but they still do not like it.
Keep the omnidirectional antenna the repeater set came with and you won't get in trouble. The vendor the other poster mentioned sells repeaters that are not only approved by the mobile phone providers but are also used by the mobile phone providers.
Keep in mind that I'm not describing a picocell or microcell, merely a local mobile phone repeater unit.
Kriston
first, the bars on your phone do not correlate to 100% signal to 10-50% signal. they often measure certain amounts of signal strength, ignoring issues like the actual quality of the signal.
a good cellular network should be accessible inside most buildings. otherwise, the network is poor. while some buildings *are* wireless-unfriendly, the issue is more often than not simply a poor network, and there's no reason my cellphone shouldn't work at wal-mart, all along the expressway, in the middle of a suburban neighborhood, etc.
i have 5/5 bars inside at home on T-Mobile. i have 5/5 bars at work on AT&T Wireless. i have 5/5 bars at school on Cingular. T-Mobile works at home and work, Cingular works at home and school, and AT&T works at work and school. had any one of those providers paid to add more cell sites at the right places, i'd have perfect coverage on one of them. instead, i have to switch between them in order to keep my phone working. but it *does* work everywhere i go -- on at least one of the providers. (AT&T works at the most places, but they don't do well around here.)
on my phone, 5 bars is -84dBm and greater. ~100ft away from a tower, my phone has read -43dBm (the highest I've ever seen on it.) the 1900MHz GSM networks here, once again, have a min RSSI (minimum signal strength) at -105dBm or -110dBm, so there can be a huge difference between different values of "5 bars".
http://www.ipaccess.com/ipaccess_2004_pages/bts.h
http://www.rivanetworks.com/nano/nano.htm
To operate one legaly you would presumably need to get an FCC experimental license for limited power output, or permission from an existing carrier.
One problem with most picocells or microcells is that they are designed to talk to the rest of a GSM network (billing and provisioning systems) and cant really be attached to a simple POTS or PRI line.
A personal GSM/VoIP gateway is one of those problems that has to get solved eventually though...
This has a basic description of the technology: http://www.umatechnology.org/technology/
Thanks for playing, but I never said anything about "bars." I am talking about signal strength and quality of the signal. Interesting how you first say that bars do not correlate, yet you use "bars" to say how good your signals are on your various phones. Make up your mind.
Your other comments are valid and interesting.
Kriston
I was _comparing_ bars, while you were comparing your "signal" as a percentage (of what?). So I assumed you got that info from bars.
Assumption: internet access. My suggestion is to purchase a wifi phone and a Linksys WRT54G wireless router along with VOIP service...oh yeah, and 2 super long range antennas for the router. The phone and the service are self-explanatory. The router has available an OSS firmware upgrade @ http://www.sveasoft.com/, one advantage of which is to up the power output to the FCC legal limit for said hardware. The antennas (research needed) are required to put that power to use. One should be able to reach a few thousand feet or so rather easily.
At one time it was possible to buy combined GSM / DECT handsets. At some levels these two protocols are quite similar, so it's not too difficult to do. Try googling for "combined DECT GSM". But they seem to have become unavailable (or only available for "campus-scale" deployments); I can only imagine it's because they didn't sell. Phyically they always looked about a generation behind "normal" GSM phones.
BTW, if you don't know what DECT is, you might be on the wrong continent...