... operators support standardization for these reasons:• To improve the compatibility of telecommunications systems;• To be able to provide wide-area or even international services;• To be able to ... An Introduction to Signals and Noise in ElectricalCommunication, New York: McGraw-Hill, 1986. Introduction to Telecommunications17is detected on the loop of subscriber B, and then an end -to- end ... is to be initiated and when it has to prepare to receive dialed digits. Inold telephones, which exchanges still have to support, this method of local-loop connection/disconnection is used to...