Wireless intercom

A wireless intercom is a telecommunications device that enables voice communication without the need to run copper wires between intercom stations. A wired intercom system may incorporate Wireless elements. There are many types of wireless intercom systems on the market. Most wireless intercom systems communicate by radio waves using one of the frequencies allotted by various government agencies. Some wireless intercom systems communicate using the 802.11 standard. There are also systems that advertise themselves as wireless, but communicate over existing building AC electrical wiring.

A wireless intercom is a telecommunications device that enables voice communication without the need to run copper wires between intercom stations. A wired intercom system may incorporate Wireless elements. There are many types of wireless intercom systems on the market. Most wireless intercom systems communicate by radio waves using one of the frequencies allotted by various government agencies. Some wireless intercom systems communicate using the 802.11 standard. There are also systems that advertise themselves as wireless, but communicate over existing building AC electrical wiring. ===Encrypted wireless=== Wired intercom is inherently private, so long as the wiring system isn't tapped by outside parties. Wireless intercom is not inherently private; conversations on a wireless intercom are broadcast using publicly available wireless frequencies which means other users with similar devices could listen in if they are within range. Most units on the market will allow intercom conversations to be heard through other devices such as scanners, baby monitors, cordless telephones, or the same brand of wireless intercom. Wireless intercom privacy can be provided if the audio stream is encrypted. Telex, HME, Altair and other intercom manufacturers offer encrypted wireless intercom for corporate, military and sports team customers desiring instant voice communications with privacy. The first use of encrypted wireless intercom in American football was in 1996; by 1999 it was being used in the Super Bowl. Audio frequency response of current products is limited to less than 4 kHz; this means that natural vocal sibilances above 4 kHz are absent. Ess sounds like eff, requiring additional spoken clarification such as saying "'S' as in 'Sam'". ==Systems that use existing electrical cabling== The first intercom systems communicated over a set of low-voltage signal wires installed in the walls of a building. The installation was typically done during the building’s construction, but buildings could be retrofitted with communication wires, at a cost. Non-radio "wireless" intercom designs were developed that used a building's existing electrical wiring to carry communication signals. Such systems work similarly to normal wired intercom designs, with intercom stations using wires to connect to electrical outlets in rooms. This method of intercom connection is most useful in offices and homes served by a single electrical service. Products are available from a variety of manufacturers including Westinghouse and GE.

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