Marconi patented a whole wireless system in 1897 and he was the first to offer a demonstration of wireless telegraphy. He built on theoretical work of Maxwell and Hertz to send and obtain Morse Code. The system used lengthy wave (1 km) signals and spark transmitter expertise, requiring very massive, high power transmitters. Using massive wave lengths additionally required long antennas. This hindered the event of mobile system, except for maritime (ship-to-shore) communications.

Since 1904 the Marconi operators used the signal ‘CQD’ as the usual emergency call sequence. Later on an operator interpreted this as an abbreviation for the textual content ‘Come Fast Danger’. In 1906 the 1st international wireless telegraphy conference was held in Berlin, Germany. There all participants agreed to use the signal ‘SOS’ as the standard emergency name sequence. Later this was interpreted as ‘Save our Ships’, ‘Save our Souls’ or ‘Ship out Succor’. Wi-fi telephony … Read the rest