Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!texbell!vector!telecom-gateway From: piet@cs.ruu.nl (Piet van Oostrum) Newsgroups: comp.dcom.telecom Subject: FAX Modems Message-ID: Date: 9 Nov 89 12:09:15 GMT Sender: news@vector.Dallas.TX.US Reply-To: piet@cs.ruu.nl Organization: Dept of Computer Science, University of Utrecht, Holland Lines: 21 Approved: telecom-request@vector.dallas.tx.us X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@vector.dallas.tx.us X-TELECOM-Digest: volume 9, issue 502, message 2 of 11 Does anyone know what kind of modulation technique is used for faxes. As I understand, a modern fax does the following: 1. The document is scanned, giving a bitmap. 2. The bitmap is compressed. 3. The compressed bitmap is sent to a remote fax, using some kind of modem and an appropriate protocol. 4. At the other side the reverse applies. My question is about step 3. What kind of modem technology is used? Are there normal modems that can be used to communicate with a fax? Is a fax card in a computer more than just a modem? When ISDN will be more prevalent will it then be possible to send faxes over ISDN? and will these be able to communicate with a normal fax? Piet* van Oostrum, Dept of Computer Science, University of Utrecht Padualaan 14, P.O. Box 80.089, 3508 TB Utrecht, The Netherlands. Telephone: +31-30-531806 Uucp: uunet!mcsun!hp4nl!ruuinf!piet Telefax: +31-30-513791 Internet: piet@cs.ruu.nl (*`Pete')