Data Communications Equipment (DCE) can be classified as equipment that transmits or receives analogue or digital signals through a network. DCE works at the physical layer of the OSI model taking data generated by Data Terminal Equipment (DTE) and converting it into a signal that can then be transmitted over a communications link. A common DCE example is a modem which works as a translator of digital and analogue signals.
DCE may also be responsible for providing timing over a serial link. In a complex network which uses directly connected routers to provide serial links, one serial interface of each connection must be configured with a clock rate to provide synchronisation. A modem is the most common kind of DCE. Other common examples are ISDN adapters, satellites, microwave stations, base stations, and network interface cards.