(1) A channel that transmits data over several wires simultaneously, typically in increments of a byte (16, 32, 64 bits, etc.).
(2) A parallel channel for IBM mainframes that transmits up to 4.5MB/sec. In byte multiplexing mode, bytes are interleaved from several low speed devices. In block multiplexing mode, the channel provides full bandwidth to the device, but can disconnect when the device does not require a data transfer such as when a disk is performing a seek. IBM's parallel channel is also known as a bus and tag channel, OEMI channel and block multiplexor channel.