... a 600 kilometres long lelephone-line between Berlin and Cologne, becomes the first 'pupinized' long-range telephone connection, when Siemens & Halske is the first firm to take up Pupin's proposal of 1899 and to successfully test the Pupin coil - which considerably improves the language understandability at the same time.

Started in 1912 with the segment Berlin-Magdeburg (Figure: conferring of contract), the "Rhineland cable" is completed in 1921 and presents itself as the precursor of the european telephone network.