Unlike the analog cordless phones you may have in your home, DECT (Digital Enhanced Cordless Telecommunications) is a digital wireless telephone technology that is expected to make cordless phones much more common in both businesses and homes in the future. Formerly called the Digital European Cordless Telecommunications standard because it was developed by European companies, DECT's present name reflects its global acceptance. Like another important wireless standard, Global System for Mobile communication (GSM), DECT uses time division multiple access (TDMA) to transmit radio signals to phones. Whereas GSM is optimized for mobile travel over large areas, DECT is designed especially for a smaller area with a large number of users, such as in cities and corporate complexes. A user can have a telephone equipped for both GSM and DECT (this is known as a dual-mode phone) and they can operate seamlessly.
DECT has five major applications:
1) The "cordless private branch exchange." A company can connect to a wired telephone company and redistribute signals by radio antenna to a large number of telephone users within the company, each with their own number. A cordless PBX would be especially useful and save costs in a company with a number of mobile employees such as those in a large warehouse.
2) Wireless Local Loop (WLL). Users in a neighborhood typically served by a telephone company wired local loop can be connected instead by a cordless phone that exchanges signals with a neighborhood antenna. A standard telephone (or any device containing a telephone such as a computer modem or fax machine) is simply plugged into a fixed access unit (FAU), which contains a transceiver. The Wireless Local Loop can be installed in an urban area where many users share the same antenna.
3) Cordless Terminal Mobility. The arrangement used by businesses for a cordless PBX can also be used by a service that provided cordless phone numbers for individual subscribers. In general, the mobility would be less than that available for GSM users.
4) Home cordless phones. A homeowner could install a single-cell antenna within the home and use it for a number of cordless phones throughout the home and garden.
5) GSM/DECT internetworking. Part of the DECT standard describes how it can interact with the GSM standard so that users can be free to move with a telephone from the outdoors (and GSM signals) into an indoor environment (and a DECT system). It's expected that many GSM service providers may want to extend their service to support DECT signals inside buildings. A dual-mode phone would automatically search first for a DECT connection, then for a GSM connection if DECT is not available.