Android as Dialup/FAX Modem

Question

With some older cell phones, you can connect them to a computer and use them as a Dialup/FAX modem (to connect to a dialup ISP for example). I have been trying to find out if this possible with Android, but all my searches end up with people looking to share their phones Internet connection with their PC. This is NOT what I'm looking to do. I'm wanting to use Hyper-terminal to have my phone place a call to a PBX, so I can make changes to the PBX remotely.

Solution 1

As I already expressed here, your stock Android phone cannot be used as an AT modem. - There isn't even a serial connection built in.

Question: How is the PBX controlled anyway? Does it implement an "analog" CSD modem, like FAX machines use(d) to?
In that case, you'd be completely out of luck since GSM/UMTS/... data transfer works quite differently.

Solution 2

It can not be that difficult to set up if you use a SIP account to fax. I have a PBX in a Flash installed at home. There I use Hylafax to communicate over SIP to my SIP provider. I guess you could use Google Voice for this?

Solution 3

It is possible using bluetooth. Most android phones (if not all) have a bluetooth dial-up service, suitable for using with e.g. Microsoft Windows Fax tool. I could not find a way to use it via USB, though.

Solution 4

It seems to me that if an app can be written to remain active during a call and send an audible tone of a specific frequency for a specific duration then the code for a terminal could be translated over (if you can get the source).

No need for bluetooth or wifi or usb.

I came here looking for an app to let me hold my phone up to a phone receiver to receive a fax or connect my headset outlet into an RJ12 phone outlet.

If I find anything useful I will try to remember to come back and post it here.

View more solutions

Comments

[Drew Chapin]

It is a straight analog modem like, like a FAX modem. For example, if I had a 56k modem in my PC and land line phone, I could use Hyper-Terminal to place a call to the PBX and administer it through Hyper-Terminal

[JimmyB]

According to different sources I found, apparently it is possible to connect a GSM device to an analog modem via a circuit switched connection. It seems that this is not supported on most devices and requires the device to support some kind of serial connection and, more importantly, the AT command set ("ATD ..."). - No way to do that on a stock Android device.

[Drew Chapin]

Can you share the links to those sources please?

[JimmyB]

Sorry, was just browsing the net. Try searching for "GSM" and "fax" or "GSM" and "analog modem".

[Drew Chapin]

Thanks! I will send you a message if I ever find anything.

[racingsnail]

Smartphones have two computers in one. The computer that runs andriod / applications and a completely separate computer that runs baseband interface to the cellular network. Baseband processor provides a serial/AT command interface to the smartphone and you can often access it by configuring USB cable as a serial modem. If/how this can easily be done varies by manufacturer usually by entering a magic dial code. Once it is switched a serial/modem device should appear on the USB port.

[Drew Chapin]

This is not what I'm looking for. I don't want to share the Internet connection. I want to use the phone to dial into and configure a remote PBX.

[LubosD]

Actually, you would. GSM supports so called "data calls" (CSD) in which fax data are not transferred as sound. I have successfully used it to send faxes in the past, but I had to call my network operator to have this activated.