György Lajtha
Networks 1978–2008: Personal Notes
By 1978, the digital transmission was already widespreadly used in telecommunication networks; standards were accepted and maintenance methods were established. After a long period of experimentations, the first stored-program time-division switches were introduced. The attenuation of optical cables gradually decreased and it became already possible to transmit signals of several hundreds of Mbps at less than 5 dB/km. These new technologies required new recommendations and new planning methods.