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GSM Voice modem for a computer?

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Hon1nbo

Sat Aug 07 2010, 11:58PM

Registered Member #902 Joined: Sun Jul 15 2007, 08:17PM
Location: North Texas
Posts: 1040

ok,
I am trying to setup an AutoPatch Repeater in my area, for emergency and priority use. However, I had to idea to make it semi-mobile (e.g: deploy where needed). I have a radio that does Cross Band repeat, and will interface with AutoPatch software which can use a standard modem with Voice Mode to make a phone call.
However, I want to try to do this with my laptop over a cell network for certain purposes (such as if we're hiking in a cellular-dead area and need to get help, I'd leave it running in my car and use my radio to make a call). I'd seen this done before but that person had a GSM Development Board at his disposal, which is over $300.
I remember seeing a PCMCIA or expresscard that took a standard SIM and simply acted as a modem, rather than a GPRS data system. I don't trust the chinese things I see on eBay, and I don't know if there is even a card designed for this at all.

Any suggestions or advice to point me in the right direction?

-Jimmy

Carbon_Rod

Sun Aug 08 2010, 05:42AM

Registered Member #65 Joined: Thu Feb 09 2006, 06:43AM
Location:
Posts: 1155

$25

Hon1nbo

Sun Aug 08 2010, 04:57PM

Registered Member #902 Joined: Sun Jul 15 2007, 08:17PM
Location: North Texas
Posts: 1040

so that will act as a modem on my computer, like the modem installed now? - it can't go through it's own software and must look like a standard dial up modem with Voice Mode... maybe I can call the company and find out, or I can tell dealextreme I am attempting to make an emergency device and they can accept a return if it doesn't work (I've worked with companies for deals before as a student and for special projects, a surprising amount are supportive).

-Jimmy

Carbon_Rod

Mon Aug 09 2010, 08:21AM

Registered Member #65 Joined: Thu Feb 09 2006, 06:43AM
Location:
Posts: 1155

It is a BenQ clone that accepts simple AT commands (there is also a Linux driver work around).
The old ARRL book had a DTMF based project that could be used to control/dial-out-of a repeater station.

Manufacturers will build products for numerous brands, but are notoriously unreliable when it comes to quality assurance. This is because a product is not associated with the actual manufacturer, but rather a retail brand name.

Note too, Soundcard based Packet Radio Modem to HF setups are older than the modern internet.

Commercial Emergency Beacons and or Satellite Phones will likely have less issues.

Cheers,

Hon1nbo

Mon Aug 09 2010, 03:26PM

Registered Member #902 Joined: Sun Jul 15 2007, 08:17PM
Location: North Texas
Posts: 1040

Carbon_Rod wrote ...

It is a BenQ clone that accepts simple AT commands (there is also a Linux driver work around).
The old ARRL book had a DTMF based project that could be used to control/dial-out-of a repeater station.

Manufacturers will build products for numerous brands, but are notoriously unreliable when it comes to quality assurance. This is because a product is not associated with the actual manufacturer, but rather a retail brand name.

Note too, Soundcard based Packet Radio Modem to HF setups are older than the modern internet.

Commercial Emergency Beacons and or Satellite Phones will likely have less issues.

Cheers,

that makes sense about the manufacturers, I've had issues with things like that (particularly with eSATA cards)

I have the rig control software that supports autopatch, I just am still not sure if this will be easily interfaced with that program.
Maybe I'll try to setup the tether on my phone in a modem mode rather than a WiFi hotspot. At least try all options before shelling out some cash.

And I mainly want to use something like this at my farm when I'm out on a hike through the wooded area. Not so much as expecting an emergency as I am expecting trouble with the vehicle. Though I would like to make this reliable enough to deploy (as a backup unit of course, there are better things for primary use).

-Jimmy

Carbon_Rod

Tue Aug 10 2010, 12:36PM

Registered Member #65 Joined: Thu Feb 09 2006, 06:43AM
Location:
Posts: 1155

Well now,
one could always make a remote DTMF decoder to modify a keypad style phone.
cell phone + MT8870DE + CD4514 + Duct tape = Routed Analog Audio
(use extended keys to Unlock/Dial/End)
or put the decoder on a PIC etc.

The local petrol station's $80 pre-paid airtime packages generally come with a free Nokia/LG phone + SIM.
And IIRC, the LG units support Voice dialing too.

Just remember, the FCC says you have to hang-up if there is music playing while on hold, and only dial toll-free numbers

Hon1nbo

Wed Aug 11 2010, 04:48PM

Registered Member #902 Joined: Sun Jul 15 2007, 08:17PM
Location: North Texas
Posts: 1040

Carbon_Rod wrote ...

Well now,
one could always make a remote DTMF decoder to modify a keypad style phone.
cell phone + MT8870DE + CD4514 + Duct tape = Routed Analog Audio
(use extended keys to Unlock/Dial/End)
or put the decoder on a PIC etc.

The local petrol station's $80 pre-paid airtime packages generally come with a free Nokia/LG phone + SIM.
And IIRC, the LG units support Voice dialing too.

Just remember, the FCC says you have to hang-up if there is music playing while on hold, and only dial toll-free numbers

but their rules also state a person may use any radio means, even if in violation of normal operating procedures such as dial only toll free numbers etc (though I don't think that would even apply for me) for anyone who needs to make themselves known for assistance. So if I get stuck out there, I can still call for help with it.

anyways, I still have a prepaid phone lying around I use for projects, maybe I could tap into that - but I'd have to be able to interface the repeater software with it. The whole point of finding a proper modem is to use the repeater software without modification.

-Jimmy

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