Glossary
A B C D E F G H I J K L M N O P Q R S T U V W X YCAP - See Carrierless Amplitude Phase
carrier - an electromagnetic wave or alternating current which is modulated to carry signals in radio, telephonic, or telegraphic transmission.
carrierless amplitude phase (CAP) - A type of quadrature amplitude modulation, used for some types of DSL, that stores pieces of a modulated message signal in memory and then reassembles the parts in the modulated wave.
central office (CO) - A telephone company facility that handles the switching of telephone calls on the public switched telephone network (PSTN) for a small regional area.
central processing unit (CPU) - The "brains" of a computer, which uses a stored program to manipulate information.
circuit-switched network - A type of network in which a continuous link is established between a source and a receiver. Circuit switching is used for voice and video to ensure that individual parts of a signal are received in the correct order by the destination site.
CLEC - See competitive local exchange carrier.
CO - See central office
common carrier - A business, including telephone and railroads, which is required by lawto provide sservice to any paying customer on a first-come, first-serve basis.
competitive local exchange carrier (CLEC) - An American term for a telephone company that was created after the Telecommunications Act of 1996 made it legal for companies to compete with the ILECs. Contrast with ILEC.
compression - The process of reducing the amount of information necessary to transmit a specific audio, video, or data signal. core network The combination of telephone switching offices and transmission plant connecting switching offices together. In the U.S. local exchange network, core networks are linked by several competing Interexchange networks; in the rest of the world the core network extends to national boundaries.
CPE - See customer premises equipment.
CPU - See central processing unit.
crosstalk - Interference from an adjacent channel.
customer premises equipment (CPE) - Any piece of equipment in a communication system that resides within the home or office. Examples include modems, television set-top boxes, telephones and televisions.
