Back to Contents PageCommunication DevicesAn electronic device that can send and receive data on the network is called a communication device. Communication devices are used on both ends of aconnection. Signals may travel from one device to another in either analog or digital form. Most communication devices have the ability to convert digitalsignals to analog signals or analog signals to digital signals, so that the signals can be transmitted from one device to another.Some of the commonly used communication devices are:Modem — Stands for Modulator and Demodulator. Modems can be analog (dial-up) or digital.Dial-up modem — Electronic devices that convert analog phone signals into digital signals that the computer can process, and digital computer signalsinto analog signals that can be transmitted over the telephone lines. Dial-up modems can be internal or external.Digital modem —Used to send and receive data to and from a digital telephone line, like Digital Subscriber Line (DSL) or Integrated Services DigitalNetwork (ISDN).Network Interface Controller (NIC) — Also referred to as network adapters or Local Area Network (LAN) adapters. They usually connect to networks using anEthernet cable. NICs can be internal (expansion cards or integrated to the system board) or external.Wireless Local Area Network (WLAN) controllers — Allow communication over short distances using radio signals instead of traditional network cabling. WLANcontrollers can be internal (expansion cards or integrated to the system board) or external.Wireless Wide Area Network (WWAN) controllers — Allow wireless connectivity through cellular tower technology. A SIM card may be is required for WWANconnectivity.
