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GSM and Asterisk Integration?
MistabewM asks: "Would it be possible to place a GSM transceiver within you home that can be tied into Asterisk in a way that would allow you to place calls from your GSM phone across your VOIP connection or though your local landline? An analogous system is being introduced on airplanes that will allow passengers to use their GSM phones in flight. I feel this would be a fantastic hack and could even be scaled up to provide large areas of free GSM service."
http://www.voip-info.org/tiki-index.php?page=How+t o+connect+VoIP+GSM+gateway+to+Asterisk+PBX
Sounds like an interesting hack indeed, but I'm not sure how it will result in a free service. Someone needs to administer the Asterisk server, pay for electricity, the bandwidth to the server and lastly don't you need a license to use GSM frequencies? If you'd be willing to cover all these costs, then sure, it will be free.
, the search term 'GSM Picocell' turns up these guys who appear to sell a GSM-to-IP product exactly like that.
-EvilMagnus
See here
But you're looking at some serious changes to your wireless hub. If you are asking, I doubt you'd be able to do it.
That's not meant as a slight, but just the truth. It's a very difficult thing to set this up. It requires more than just running some daemon. It also requires authenticated sessions on the servers. If you aren't Ericsson, you aren't getting into the network.
That isn't to say that you couldn't implement this yourself. Skype, for example, doesn't run across the traditional long distance network, but it provides long distance phone service over the Internet. If you are willing to dive headlong into a long and arduous development plan, sure, you could implement this.
Don't hold it against me that I'm not holding my breath for this, though.
Jesus saved me from my past. He can save you as well.
Let me rephrase the poster... ;-)
Hello Slashdot,
I want to start a mobile phone company with no money down. I am very poor but I want to provide GSM, voice mail, fax, voip, free calls, etc. Can you people help me?
Short answer: No.
Long answer: The main restriction here is the use of restricted frequencies, and some "minor" technical hurdles.
while it's perfectly OK for you, as a lone individual, or a company, to operate a GSM handset, operating a base-station is another thing. First, you'd have to get your greedy paws on a basestation, then you'd have to make your own SIM cards (hijacking calls that should be on the regular operator's network is highly illegal (DMCA); there's all sorts of (broken) encryption going on), and you'd have to outfit phones with 2 SIM cards, switching from your own network to the other (which entails switching the phone off and on again) every time you enter or leave the building. (This is doable, but annoying).
Now, assuming you don't want the legal hassles of paying for multi-million dollar cell network licenses, you could operate a "pirate" basestation on some frequencies that aren't used too much where you're at (you'd have to measure it through first).
In other words; you're better off investing in a handset that does both GSM and DECT(or whatever you use for domestic wireless phones in the US) or even both GSM and WiFi. There aren't many of those (though BritishTelecom has announced their model), but there should be some out there.
SCO employee? Check out the bounty
Ok, the equipment:
One microcell, coming right up.
Ok, simple omnidirectional antenna.
Then you need the base station that drives that antenna.
Then you need the base station controller that drives the base station.
Then you need MSC (mobile switching center...) that actually gets the calls from the base station and forwards it accordingly to an SS7 network.
Then you need to set up Asterisk to talk to that SS7 network and grab your phone calls.
And all the rest of the components that I have forgotten.. In effect, you need to become a full-blown telco, albeit with only one base station.
All the equipment can be bought from Nokia, Ericcson or other mobile network vendors. Price range is not for home users.
Then, you need to get a license to operate that basestation. 900/1800/1900MHz is a licensed band. This *might* be quite easy if the location is just a single cell.
Anyway, then you need to apply for Mobile Network Identifiers (MCC + the rest) to distinguish yourself as a GSM operator, so when you search for networks with your GSM phone, you'll see your own network as one.
Then you need to get a SIM Card to use with your phone that has access to your network. (Or, you may be able to set it to "open for all" mode).
(Of course, if the question was simply if you can reaac GSM network via Voip and want to set up the gateway your own home, then that's easy, just plug a phone or wireless modem to your Linux box....but I was under the impression that this meant the ability to use your GSM phone as a "cordless phone".)
With landline this is of course easy, all you need is a modem waiting for calls..
I have an 'unlimited incoming local calls' feature on my phone, combined with 100 minutes (practically nothing) of outbound calling per month. I pick up my mobile, dial a number, punch in an extension, and then hang up. This process takes about 5-6 seconds.
After I hang up, my home phone number calls my mobile phone and gives me an IVR (Voice Menu) where I can dial out using VOIP long-distance.
The call is free, because it looks like an incoming call from my home, but I'm using my home line to make the VOIP call outbound from my cell phone.
This is my trick; the only inconvenience is that you have to dial a number BEFORE you make outbound calls, but I can live with it. =)
-Jesse
No, in most juristictions, it's illegal to operate your own base station on any of the frequencies supported by GSM (850, 900, 1800, and 1900MHz, I think 450MHz is coming on stream in various places too. But that's also a problem.)
However, there's a new system called UMA that tunnels the GSM protocols through an IP connection provided by either an 802.11 base station or some form of bluetooth receiver. The system has some limitations in its present form, the major ones being:
- Few carriers support it. In the US, practically none do.
- Few phones are available that support it. In theory, most bluetooth supporting phones could be made to support it with a firmware update. But that's not likely to happen. I know the UK version of Motorola's RAZR V3 now supports the feature, but it's in a small class of phones and the US version doesn't yet.
- Each "base station" has to be registered by the GSM operator, I have NO IDEA why. That means plain old open WAPs in malls wouldn't provide a solution to poor coverage inside them, for instance, and you (probably) couldn't use the system to defeat roaming charges by using a Starbucks WiFi connection in the UK with your Cingular phone.
It also isn't exactly what you've asked for. It's largely seen as a system to help phone users improve their reception and reduce their dependence on the capacity of the wide range GSM network. It's designed to be seamless, you can start a call on the 802.11 network, step "out of range", and the call will transfer to a nearby GSM tower just as it would if you were going out of range of any other GSM tower.By comparison, it looks like you're just after a way to turn a GSM phone into a cordless handset.
I've covered the system in my journal. It'd be nice to see it better supported, and to see other standards also adopt it such as the CDMA ones. Much of the issues of capacity and poor reception would be dealt with if the system became a standard part of most people's mobile phones.
You are not alone. This is not normal. None of this is normal.
This is a general reply to all the +5 comments that are saying stuff like 'picocell' and 'well, you could modify xyz and ... but you'd still need to sign on to the provider's network'
Look. It is very simple. Take advantage of the 'free calling to other members' most providers offer. I.e. Add a tmobile phone to your plan and make your plan a shared-minutes plan. Get free tmobile to tmoble. Make liberal use of the headset port.
Take ANY GSM phone that has a good USB and headset interface. A bit of straightforward hacking (as asterisk already supports sound cards for in and outbound sound channels) gets the headset connected to the asterisk box. Now all you need to do is press buttons on the phone.
Enter the usb interface, basically a com port in disguise. ATDT ring a bell? A lot of phones support this last time I checked. Most motorola phones for sure so you can dial folks in your bluetooth organizer with the click of a wand. Instead, you can just have Asterisk decode the DTMF and (with a dialing rule) when you've dialed 7 or 10 digits, it will encode it as an ATDT string, send to the phone, and connect the audio channels.
Ta-Da. It works, by the way (though instead of a USB interface I just hacked the keypad interface as it was more convenient for me to do that with the equipment I have. My interface is on a com port and tied together with an Atmel microcontroller FYI I did this initially because I was annoyed I had to pay to call to check my VM on my office phone).