Slashdot Mirror
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."
, the search term 'GSM Picocell' turns up these guys who appear to sell a GSM-to-IP product exactly like that.
-EvilMagnus
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.
To legally set up a GSM transceiver you would need to purchase a licence. Well, I'm sure thats the case in most countries anyway.
I know that the mobile phone companies in the UK spent a hell of a lot of cash to secure 3G licences, they wouldn't be too happy if you got to set up your own transceiver for free.
Yes, I know a handset is a transceiver, but that probably comes under some kind of different licence.
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..
http://store.voxilla.com/customer/product.php?prod uctid=16136
Basically, get two phones and a plan with free mobile-to-mobile minutes. Leave one at home in the base station and connect it to Asterisk with a DTA.
Call home with your mobile, then call again from there to where ever via VoIP. Basically a cell-to-VoIP gateway.
There is a FAQ somewhere around that explains exactly how to do this.
-Charles
Learning HOW to think is more important than learning WHAT to think.
There is a device called cellsocket that my company uses to connect regular analog telephones up to cellphones. You pick up the phone, hear a dial tone, then dial as you normally would, but it uses your cellphone for the connection. You could possibly connect something like this to your house POTS wiring and use your regular phones in the house while your cellphone sits and charges.
As far as making VOIP calls, there is the Sipura-3000 which mentions something similar to what you are asking. The manual is located at:
http://www.sipura.com/Documents/SPA-3000.pdf/
You could purchase or set up an Asterisk server for this purpose, integrating a POTS line, Cell line,and various SIP services, etc. That will run into quite a bit of an expense and configuration though. A Digium card Wildcard TDM400P http://www.digum.com/ with a combination of FXO and FXS modules would probably be what you need.
It's a lot of effort though, and possibly a lot of expense. I would try out the Sipura-3000 and a CellSocket type adapter first. I have 3 Sipura devices so far, and they work nicely, and are fairly easy to set up.
--dingletec--
Not really. The GSM gateway discussed is not a GSM cell - its just another GSM client. You can of course call it and be connected to your local PBX - but you'd do so using some GSM operator's cells, which is hardly what the post asked. You seem to be confusing GSM with peer-to-peer radio. I know peer-to-peer is all the rage now, but please, do get a clue.
You walk into the building and your mobile would switch to pbx mode - local extension at your desk mobile style. Low output power too - no brain tumours.
The problem with PicoCell and Nanocell is twofold - cost and SIP Compatibility. What you want is something like this device from 2N.
Voice Blue Lite
This device is supposed to cost about 3500$ USD (only reference I could find online), and creates a mini-gsm cell backed by a SIP provider. This device has been tested with Asterisk.
Sparkfun.com sells an OEM GSM module kit for $229 which contains antenna, module, PCB, camera, and USB interface. This OEM module, a Telit GM862, has full GSM and GRPS functionality, including audio and camera phone functions. You could easily adapt it to an astrisk system.
I purchased one of these kits a while back, and you have enough functionality to create your own home-brew cellular phone.
>It is illegal to transmit anywhere else without a license, regardless of power./ Documents/bulletins/oet63/oet63rev.pdf
http://www.fcc.gov/Bureaus/Engineering_Technology
Specificall at the PCS frequency 1.705-2.1735 MHz the maximum legal power is 100 uV/M at 30 M
The parts of my extensions conf that you need to know are:
/var/spool/asterisk/outgoing/callme.call
exten => 123,1,Answer
exten => 123,2,System(/etc/asterisk/callme)
exten => 123,3,Hangup
The 'callme' file is a bash script that looks alittle something like this:
#!/bin/bash
sleep 4
umask 000
(
echo "Channel: IAX2/loginname:password@provider/8885555555"
echo "Callerid: Magic"
echo "MaxRetries:1"
echo "RetryTime: 10"
echo "WaitTime: 30"
echo "Context: internal"
echo "Extension: 444" ; the extension of the IVR
echo "Priority: 1"
) >
That will wait for 4 seconds before calling the mobile so that you have a chance to hang up after you press '123' after calling in.
In my example, you use an IVR with the number '444' which forwards to the IVR 'callme-menu' presented as soon as you pick up your cell, here's the part from my extensions for that:
[callme-menu]
exten => s,1,Answer ; Answer the line
exten => s,2,DigitTimeout,5 ; Set Digit Timeout to 5 sec
exten => s,3,ResponseTimeout,7 ; Set response timeout to 7 sec
exten => s,4,Wait(2) ; Wait two seconds to make sure speaker is at ear
exten => s,5,Background(what-are-you-wearing) ; Greeting call
exten => _9X.,1,SetCallerID(JESSE)
exten => _9X.,2,Background(pls-wait-connect-call)
exten => _9X.,3,Goto(outbound,${EXTEN:1},1)
exten => _9X.,4,Congestion
I hope this helps you. I think I'll put it on the wiki this weekend so more people can screw the system.
=)
-Jesse