Bus extension, or bus expansion, is a technology that increases the number of bus slots of the same or different bus types for a host computer system. It is usually achieved by installing an extension card in the host computer and cabling it to a separate housing that contains a backplane and its own power supply to accommodate peripheral devices.

Typically, a bus extension system is composed of three major parts, an extension card installed in the host computer, an extension chassis to provide more bus slots, and a specialized cable to connect them. The extension card works as a transparent bus bridge. Though the host computer and the extension chassis are physically separated, they are logically the same computer system. All cards installed in the extension chassis are recognized and operated as if they were installed in the host computer, without any additional drivers or software needed.

Type of Bus Extension Solutions