Editing Baseband (section)

=== Baseband channel ===
A ''baseband channel'' or ''lowpass channel'' (or ''system'', or ''network'') is a [[communication channel]] that can transfer frequencies that are very near zero.<ref>{{cite book | title = Digital Signal Transmission | author = Chris C. Bissell and David A. Chapman | publisher = Cambridge University Press | year = 1992 | isbn = 0-521-42557-3 | url = https://books.google.com/books?id=cj12nN2uW0AC&dq=called-baseband-channels&pg=PA149}}</ref> Examples are serial cables and [[local area network]]s (LANs), as opposed to [[passband]] channels such as radio frequency channels and passband filtered wires of the analog telephone network. [[Frequency division multiplexing]] (FDM) allows an analog telephone wire to carry a baseband telephone call, concurrently as one or several carrier-modulated telephone calls.