Why digital? For a long time, many communications systems were analogue – they simply transformed voice into a similar electrical signal to be carried across a pair of wires.
Digital transmission technology, which is the ability to transform virtually any content into a digital signal – a stream of numbers – and to convey it over any digital communications infrastructure, has changed telecommunications.
Now everything is digital and we can mix voice, video, messages, and even a bank transfer across the same infrastructure. We have digital music, digital photos, digital radio, digital TV and, of course, digital telephony. Digital transmission technology means that we are able to send information from anywhere to anywhere.
Very high-speed digital networks such as ours have been made possible by advances in digital transmission, a consequence of developments in electronics, electromagnetics and information theory. The reliable conveyance of signals at high speeds is achieved using a synchronised national network of transmission links (Synchronous Digital Hierarchy or SDH) using Time Division Multiplexing (TDM) to share many channels on each link, carried over the optical fibre DWDM systems. A ring topology is used to provide further redundancy should any fibre break.
Read more about the telecommunications technology available to all our customers.