How to transmit a fax via sound output from a computer?

I'm using Windows 7 on a Laptop, but I have not any modem hardware embedded on it...

I know that faxes are normally transmitted (received and sent) via AT commands through a serial port to a modem device that supports that AT commands.

I tried to use my mobile phone to try to send a fax, but I could not do that (perhaps it does not support that kind of commands).

So, I'm trying to do something different. Some years ago, a friend show me how to dial a number from a phone without typing its keys, only getting a mobile phone next to phone's microphone and then dialing on it, i.e., using the DTMF tone dialing from another phone. Then I thought:

Is it possible to use a software to convert fax protocol to sound communication to a mobile phone, like I dial the number on my mobile phone and wait for "fax signal" and then starting to send data from my sound card?

It is possible to automatize it including a "printer driver" that can be used by Windows 7 Fax software?

kokbira

Posted 2012-07-18T15:28:06.573

Reputation: 4 883

1Wouldn't it be easier to send the fax via an email-to-fax gateway? ;) – Julian Knight – 2012-07-18T15:31:42.853

1Drat. you beat me to it. This is precisely what we used at work. – Hennes – 2012-07-18T15:35:41.150

Something like this has already been asked: http://stackoverflow.com/questions/4483662/convert-data-to-sound-and-back , just not involving fax.

– MaQleod – 2012-07-18T15:44:23.493

1This is like trying to put out a fire by spitting on it. How about you just use the correct tools for the job, in other words, use a any number of internet fax services with a USB Fax/Printer/Scanner. – Ramhound – 2012-07-18T15:54:50.533

Well, I just wanna to do it in a superuser way ;) Also, I would like to use a free service in some emergency cases, like when I have only 1 computer (with needed software) and 1 mobile phone... – kokbira – 2012-07-18T21:04:54.687

@MaQleod, I googled for something like "fax via sound card" and found a solution from transferring a file using certain "sound" protocol, not the default fax protocol. It was nice, but a particular solution, not one that can be used for any fax transfer... – kokbira – 2012-07-18T21:08:28.777

Answers

An interesting question.

Back in the old days we used to have something called an acoustic coupler which did just that. So yes, in theory it could work.

In praxis you will run into problems.

E.g. the microphone on the phone might distort the sound of your fax. Our your speakers might do that. Or the software in the mobile will drop parts of the audio which are not audible to humans. I can probably think of a few more problems.

A practical solution might be on of the 'email to fax' services on the web.

Hennes

Posted 2012-07-18T15:28:06.573

Reputation: 60 739

Chances are that the audio quality on your wireless provider's network is not proper for reliable fax use... or maybe not even for occasional and sporadic fax use with little reliability. You'd be much better-served to spend your time doing it in a reliable fashion.

Lee Howard

Posted 2012-07-18T15:28:06.573

Reputation: 11