Intercom: Wired, Wireless and Telephone Intercom Systems
Opting for wireless intercom is more beneficial than purchasing the standard wired intercoms. With wireless intercoms, no wires are needed for installation which is great for places where setting up of wires is not possible. One can save money that would go when setting the wires of a wired intercom. Also, wireless intercom is a portable system which means the user can easily carry the units around or transfer it from one place to another.
However, interference problem with the intercom can still be encountered with other wireless intercoms and devices as well as with electrical units. Wireless devices like wireless data networks, remote audio speakers and cordless telephones can interfere with communication. Motors, transformers, and lighting fixtures are some of the electrical units that cause interference like emitting noise upon transmission. And in wireless intercom, conversations can be overheard or picked up with other wireless intercoms of similar frequency such as baby monitors, scanner, and cordless phones.
Though nowadays, wireless intercom comes with encryptions thus making the communication more secure and private. If the intercom was constructed properly, placed and installed in the right location, and has been grounded and shielded well, interference from outside sources is less likely to occur. The frequency ranges of wireless intercoms and products made available to the public by United States and in Canada are 49 MHz, FM band (200 kHz - 270 kHz), 494-608 MHz, 900 MHz, 2.4 GHz, 5.8 GHz and MURS (150 MHz).
But with power line communication units, despite its being a non wireless product it is sold and included in the wireless intercom category. Transmission of signals is through the existing house wiring or the wiring above the building. It is said to be wireless for the reason that similar to wireless products, wires are not required.
With the technology of today, telephone units can be made into intercom. Not only can one use the unit to communicate but paging is also possible as long as it is done with similar units or models. To name some are TMC model ET4300, AT&T models 945 and 974, and Panasonic model KX-TS3282W(/B).
For telephones that have general phone line, adding a device that comes with intercom function can give identical functionality to the telephone unit. Installation can be done easily, radio interference is no more, and privacy issues that come with some of the wireless intercom is not a problem. The Add-A-Com Whole House Intercom for Standard Telephone System is an example of this telephone intercom.
When the intercom paging is activated, one hears a very distinctive ring coming from the telephones as soon as a phone is off the hook. As soon as the external phone is disconnected in this instance, the phones are turned into an intercom and only ended once the phones are hooked again which in turn reconnects the external phone. Although even in the middle of using the intercom, incoming external calls can be still noted for a ringing sound will be heard over the earpiece. The telephone intercom and wireless intercom are both alike in the way of communication ease and convenience.