ABSTRACT
This chapter discusses the nature of cable modems and describes their operation. It includes the cabling infrastructure being developed to provide a megabit transmission facility to residences and businesses. The chapter outlines the cabling requirements for installation within buildings, requirements that are necessary to access this new high-speed information highway via the use of cable modems. The ability to appreciate why cable modems are able to provide a transmission capability that is an order of magnitude or more than conventional modems used for transmission on the switched telephone network, requires knowledge of certain transmission concepts, including the Nyquist theorem. In 1924, Nyquist proved, in what is now referred to as the Nyquist theorem, that the maximum signaling rate of a device is limited to twice the available bandwidth; beyond that rate, inter-symbol interference occurs and adversely affects the transmission.
