However, its most popular application is single-cell cordless phones connected to traditional analog telephone, primarily in home and small-office systems, though gateways with multi-cell DECT and/or DECT repeaters are also available in many private branch exchange (PBX) systems for medium and large businesses, produced by Panasonic, Mitel, Gigaset, Ascom, Cisco, Grandstream, Snom, Spectralink, and RTX.

DECT can also be used for purposes other than cordless phones, such as baby monitors, wireless microphones and industrial sensors.

GAP-conformance enables DECT handsets and bases from different manufacturers to interoperate at the most basic level of functionality, that of making and receiving calls.

CAT-iq allows interchangeability across IP-DECT base stations and handsets from different manufacturers, while maintaining backward compatibility with GAP equipment.

Named Digital European Cordless Telephone at its launch by CEPT in November 1987; its name was soon changed to Digital European Cordless Telecommunications, following a suggestion by Enrico Tosato of Italy, to reflect its broader range of application including data services.

The ETSI TS 102 527 series comes in five parts and covers wideband audio and mandatory interoperability features between handsets and base stations.

The standard was created to enable home automation, security, healthcare and energy monitoring applications that are battery powered.

DECT ULE uses a simple star network topology, so many devices in the home are connected to a single control unit.

This codec is designed for high-quality voice and music applications such as wireless speakers, headphones, headsets, and microphones.

[11][12] DECT-2020 New Radio protocol was published in July 2020; it defines a new physical interface based on cyclic prefix orthogonal frequency-division multiplexing (CP-OFDM) capable of up to 1.2 Gbit/s transfer rate with QAM-1024 modulation.

The updated standard supports multi-antenna MIMO and beamforming, FEC channel coding, and hybrid automatic repeat request.

[22] DECT has been used for wireless local loop as a substitute for copper pairs in the "last mile" in countries such as India and South Africa.

By using directional antennas and sacrificing some traffic capacity, cell coverage could extend to over 10 kilometres (6.2 mi).

A precursor to Wi-Fi, Net3 was a micro-cellular data-only network with fast roaming between base stations and 520 kbit/s transmission rates.

Typical abilities of a domestic DECT Generic Access Profile (GAP) system include multiple handsets to one base station and one phone line socket.

If frequency-hopping is avoided, each base station can provide up to 120 channels in the DECT spectrum before frequency reuse.

Each timeslot can be assigned to a different channel in order to exploit advantages of frequency hopping and to avoid interference from other users in asynchronous fashion.

It is generally immune to interference from other DECT systems, Wi-Fi networks, video senders, Bluetooth technology, baby monitors and other wireless devices.

With high quality connections, 2-, 4- or 8-level differential PSK modulation (DBPSK, DQPSK or D8PSK), which is similar to QAM-2, QAM-4 and QAM-8, can be used to transmit 1, 2, or 3 bits per each symbol.

DECT provides dynamic channel selection and assignment; the choice of transmission frequency and time slot is always made by the mobile terminal.

For this purpose, DECT devices scan all idle channels at regular 30 s intervals to generate a received signal strength indication (RSSI) list.

Unlike the GSM protocol, the DECT network specifications do not define cross-linkages between the operation of the entities (for example, Mobility Management and Call Control).

The base can request authentication by sending two random numbers to the handset, which calculates the response using the shared 128-bit key.

[26] Unfortunately very few DECT devices on the market implemented authentication and encryption procedures[26][27] – and even when encryption was used by the phone, it was possible to implement a man-in-the-middle attack impersonating a DECT base station and revert to unencrypted mode – which allows calls to be listened to, recorded, and re-routed to a different destination.

[34] Bandwidth is half as wide as that used in Europe (1880–1900 MHz), the 4 mW average transmission power reduces range compared to the 10 mW permitted in Europe, and the commonplace lack of GAP compatibility among US vendors binds customers to a single vendor.

North-American DECT 6.0 products may not be used in Europe, Pakistan,[37] Sri Lanka,[38] and Africa, as they cause and suffer from interference with the local cellular networks.

CAT-iq 2.0/2.1 feature set is designed to support IP-DECT base stations found in office IP-PBX and home gateways.

[41][42] The standard was designed to meet a subset of the ITU IMT-2020 5G requirements that are applicable to IOT and Industrial internet of things.

With good range (up to 200 metres (660 ft) indoors and 6 kilometres (3.7 mi) using directional antennae outdoors), dedicated spectrum, high interference immunity, open interoperability and data speeds of around 500 kbit/s, DECT appeared at one time to be a superior alternative to Wi-Fi.

DECT uses UHF radio, similar to mobile phones, baby monitors, Wi-Fi, and other cordless telephone technologies.