An intercom (intercommunication system) is a standalone, closed-circuit system for one-way “simplex” and/or two-way “duplex” communication. The general purpose of a professional intercom system is to facilitate simple to complex communication setups for few to thousands of users who need to be continuously on talk and/or listen mode. Two-way communications systems can operate in half-duplex or full-duplex. With
half-duplex systems, one party talks while the other party listens. With full-duplex systems, both parties can talk and listen at the same time as if they are in a natural conversation in person.
Users who have different roles in a particular operation can be in a conference or partyline together. Or they can be sub-divided into a matrix of independent groups in any one or many private intercom channels. In addition to establishing communication points, an intercom system can also be interfaced with third-party devices such as 2-way radios, 4-wire audios, telephone, TV cameras, AES3 digital audio, relay control
(for signal light activation or door control), etc.
The core technology of an intercom system could be based on one of the following platforms: 2-wire/analog, 4-wire digital, wireless, or IP networks. The decision to deploy one platform over the other will greatly depend on requirements, environment and budget. These intercom platforms operate independently or can be linked to form a larger system in order to meet specific unique communication workflow needs.
Moreover, intercom systems can be bridged together with different communications systems as part of a multi-platform solution.
In certain applications, intercom systems need to be geographically distributed to support the various communication positions in a given workflow. Therefore, they can be connected over 2-wire or 4-wire; MADI for close-distance connections such as floor-to-floor; optical fiber for short to long distances within a building; and IP networks (LAN, WAN, or Internet) for connections across a wide area, across town, or across the country.