<P> On 13 May 1897, Marconi, assisted by George Kemp, a Cardiff Post Office engineer, transmitted the first wireless signals over water to Lavernock (near Penarth in Wales) from Flat Holm . The message sent was "ARE YOU READY". From his Fraserburgh base, he transmitted the first long - distance, cross-country wireless signal to Poldhu in Cornwall . His star rising, he was soon sending signals across The English channel (1899), from shore to ship (1899) and finally across the Atlantic (1901). A study of these demonstrations of radio, with scientists trying to work out how a phenomenon predicted to have a short range could transmit "over the horizon", led to the discovery of a radio reflecting layer in the Earth's atmosphere in 1902, later called the ionosphere . </P> <P> Radiotelegraphy proved effective for rescue work in sea disasters by enabling effective communication between ships and from ship to shore . In 1904, Marconi began the first commercial service to transmit nightly news summaries to subscribing ships, which could incorporate them into their on - board newspapers . A regular transatlantic radio - telegraph service was finally begun on 17 October 1907 . Notably, Marconi's apparatus was used to help rescue efforts after the sinking of Titanic . Britain's postmaster - general summed up, referring to the Titanic disaster, "Those who have been saved, have been saved through one man, Mr. Marconi...and his marvellous invention ." </P> <P> Around 1965, DARPA commissioned a study of decentralised switching systems . Some of the ideas developed in this study provided inspiration for the development of the ARPANET packet switching research network, which later grew to become the public Internet . </P> <P> As the PSTN became a digital network, T - carrier "synchronous" networks became commonplace in the U.S. A T1 line has a "frame" of 193 bits that repeats 8000 times per second . The first bit called the "sync" bit alternates between 1 and 0 to identify the start of the frames . The rest of the frame provides 8 bits for each of 24 separate voice or data channels . Customarily, a T - 1 link is sent over a balanced twisted pair, isolated with transformers to prevent current flow . Europeans adopted a similar system (E-1) of 32 channels (with one channel for frame synchronisation). </P>

Transmitting data in a telegraph system used the