What is SFN?
SFN is “Single Frequency Network”. An SFN system allows a set of transmitters with overlapping coverage areas to transmit on the same set of frequencies. At present all UK analogue and digital terrestrial televisions transmissions use an MFN (Multi Frequency Network) system, whereby transmitters with overlapping coverage areas transmit on different fequencies. It would appear that there is an inherent problem in using an SFN system for television with widely separated transmitters due to the difference in propogation delays. Some engineering tests of SFN systems for digital terrestrial television transmissions have been conducted in various parts of the world including Australia, and a few SFN systems are now in use over small areas in some countries (Paris, France; Singapore; parts of Portugal and Spain). Several more SFN systems are being considered for the future, including for southern Britain and for East Anglia. According to a few sources, all UK Freeview boxes would be capable o
