Introduction [to the Special Issue]

This is the second special issue on telecommunication circuits to be published in the IEEE Journal of Solid-State Circuits. Since the first was published in February 1979, there have been many advances in ICs for both switching and transmission systems. This issue starts with two overview papers and then presents five groups of papers describing integrated circuits for subscriber-line interfacing and switching, voice coding and decoding, frequency-division multiplexing (FDM), digital network data processing, and signal processing.