Right after AT&T’s divestiture on January 1, 1984, the Regional Bell operating companies, RBOCs (i.e., all the telephone companies that monopolized local telephone service) charged the then newly-formed Bell Communications Research (Bellcore) – which consisted of about half of the famed legendary Bell Labs – to develop a new TDM scheme for transmission and switching of optical signals. The result was SONET (synchronous optical network). SONET was so well conceived that it was quickly standardized by the ITU in the 1980’s, and renamed as the Synchronous Digital Hierarchy (SDH) standard. A SONET industry has thrived since, as virtually the entire core of the Internet is SONET/SDH. One of the goals of SONEt was to resolve the hidden signaling problems that the traditional digital signal hierarchy (T1, T2, T3, etc.) suffered from.
Research the ingeniously-designed SONET TDM scheme, in comparison to the T1-T3 scheme, and discuss the SONET advantages, and its implementation configurations in various types of networks.