Group 4 Fax
The Groups relate the speed and sophistication of the fax machine. The standards were developed by the ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) in order that fax machines from different manufactures could communicate. Group 4 faxes operate on a 64Kbps ISDN (Integrated Services Digital Network) B Channel. Consequently, unlike Group 3 faxes, the digital scan information is not converted into an analogue signal.