four-wire separate connection
11Telephone exchange — A telephone operator manually connecting calls with cord pairs at a telephone switchboard. In the field of telecommunications, a telephone exchange or telephone switch is a system of electronic components that connects telephone calls. A central… …
12Number Five Crossbar Switching System — The Number Five Crossbar Switching System or 5XB switch, designed by Bell Labs and made by Western Electric, was in use in Bell System telephone exchanges from 1948 to the 1980s. Its principal use was as a Class 5 telephone switch, though… …
13Light-emitting diode — LED redirects here. For other uses, see LED (disambiguation). Light emitting diode Red, pure green and blue LEDs of the 5mm diffused type Type Passive, optoelectronic Working principle Electr …
14modem — /moh deuhm, dem/, Computers. n. 1. an electronic device that makes possible the transmission of data to or from a computer via telephone or other communication lines. v.t. 2. to send or receive (information, data, or the like) via a modem.… …
15Electrical wiring (United States) — Electrical wiring in general refers to conductors used to carry electricity and their accessories. General aspects of electrical wiring as used to provide power in or to buildings and structures, commonly referred to as building wiring, are… …
16Power supply unit (computer) — Power supply unit with top cover removed A power supply unit (PSU) supplies direct current (DC) power to the other components in a computer. It converts general purpose alternating current (AC) electric power from the mains (110 V to… …
17Integrated Services Digital Network — ISDN redirects here. For other uses, see ISDN (disambiguation). Integrated Services Digital Network (ISDN) is a set of communications standards for simultaneous digital transmission of voice, video, data, and other network services over the… …
18Diver communications — are the methods used by divers to communicate with each other or with surface members of the dive team. There are several distinct forms of diver communications: Voice communications Most professional diving equipment such as full face diving… …
19Echo cancellation — The term echo cancellation is used in telephony to describe the process of removing echo from a voice communication in order to improve voice quality on a telephone call. In addition to improving subjective quality, this process increases the… …
20AppleTalk — is a proprietary suite of protocols developed by Apple Inc. for networking computers. It was included in the original Macintosh released in 1984, but is now unsupported as of the release of Mac OS X v10.6 in 2009[1] in favor of TCP/IP networking …
