Q. What is Data Transmission and Modems?

Data can be transferred between two stations in either serial or parallel transmission. Parallel data transmission, in which a group of bitsmoves over several lines at the same time, is used when the two stations are close to each other (usually within a few meters), as in a computer-printer configuration. Serial data transmission, in which a stream of bits moves one by one over a single line, is used over a long distance. Serial data transfer can be either asynchronous or synchronous. Asynchronous data communication is most commonly applied in low-speed terminals and small computers. Large-scale integration (LSI) devices known as UARTs (universal asynchronous receivers/transmitters) are commercially available for asynchronous data transfer. Synchronous data communication is used for transferring large amounts of data at high speed. USARTs (universal synchronous/asynchronous receivers/transmitters) are commercially available LSI devices.