Digital Enhanced Cordless Telecommunications (DECTTM) is the ETSI standard for short-range cordless communications, which can be adapted for many applications and can be used over license exempt frequency allocations world-wide. The accumulated number of DECT devices manufactured reaches more than one billion with a growing ratio of more than 100 million devices per year.
DECT is suited to voice (including PSTN and VoIP telephony), data and networking applications with a range up to 500 metres.
DECT dominates the cordless residential market and the enterprise PABX (Private Automatic Branch eXchange) market. The capability of the standard for telephony applications is unrivalled by any other technology. In addition to a complete repertory of signalling and procedures for PSTN and ISDN scenarios, TC DECT has developed (as part of New Generation DECT) a complete set of signalling procedures for VoIP telephony. This makes the achievement of real interoperability from an end user perspective possible.
DECT ULE (Ultra Low Energy) has been developed to open the technology to the M2M market.
DECT Evolution has been developed to provide new features for high-end and professional audio system applications, such as those used by the PMSE industry, where audio streaming with higher data rates and very low latency is essential.
DECT-2020 is the latest development providing very reliable radio transmission supporting advanced channel coding and Hybrid ARQ with incremental redundancy, which enables fast re-transmission. The physical layer supports fast link adaptation, transmit and receiver diversity, as well as MIMO operations up to 8 streams. DECT-2020 covers star network topology, e.g. for URLLC use cases, as well as mesh network topology, e.g. for mMTC use cases.
A World-wide standard
DECT was initially developed as a European standard. It was later adopted by many other countries and today has become a world-wide de-facto standard for cordless telephony applications.
Currently, DECT is available almost worldwide (the technology has been adopted in over 110 countries). The United States market is now one of the most important markets in terms of expansion. DECT is also deployed in South Korea and also Japan has opened the market to the technology, a market traditionally dominated by the Personal Handy-phone System (PHS).
The most commonly used spectrum allocation is 1 880 MHz to 1 900 MHz in Europe. This spectrum is license exempt and technology exclusive, which ensures an interference free operation, and contributes to the very high spectral efficiency of the technology. The bands 1 900 MHz to 1 920 MHz and 1 910 MHz to 1 930 MHz are also very common in many countries outside Europe. In the US the frequency allocation is 1 920 MHz to 1 930 MHz, known as UPCS band. In this case, the allocation is not technology exclusive, but is, in practice, "clean" enough to achieve similar interference-free operation.
Frequency allocation in Europe of 1 900 MHz to 1 920 MHz (shared with UTRAN TDD) has been foreseen by IMT-2000 for potential expansion of the standard.
The DECT-2020 NR physical layer is in principle suited to address any frequency bands below 6 GHz.
Our Role & Activities
The TC DECT standard is continually updated in order to take into account the developments in the technology, including DECTTM New Generation, DECTTM Ultra Low Energy (ULE), DECT Evolution, DECT-2020 NR and regional variants.
The New Generation DECT
New Generation DECT (NG-DECT) is the name given to the development of the DECT standard with primary target on VoIP applications. NG-DECT is implemented by the addition of new functions to the DECT base standard (keeping back-compatibility with all previous developments) and the creation of a dedicated set of Application Profiles defining new types of products.
New Generation DECT includes the following features:
- Superior voice quality better than any existing technology (Wideband and super-wideband Speech)
- Complete set of signalling and procedures for VoIP (SIP and H.323) and mixed (base stations with dual PSTN and VoIP connectivity) scenarios
- New DECT headset devices (with DECT radio i/f)
- Support of Broadband Data and Audio Streaming
- Video telephony capability
- Home Monitoring, Door phone, Baby monitor, Mailbox
- Plug & Play functionality of all components
- Automatic device detection and configuration (easy pairing)
- Software update over the air (SUOTA) for handsets and other cordless devices
New Generation DECT specifications focus on Wideband speech (TS 102 527-1), IP Packet data (TS 102 527-2), Extended Wideband speech services (TS 102 527-3) Light Data Services (TS 102 527-4) and additional set of features for extended wideband speech (TS 102 527-5).
DECT Ultra Low Energy (ULE)
DECT Ultra Low Energy (ULE) is a new technology based on DECT and intended for Machine-to-Machine communications such as Home and Industrial automation. The main characteristics of the technology are ultra-low power consumption (much lower than IEEE 802.11) and wider coverage (much wider than IEEE 802.15 and Bluetooth Low Energy).
The technology is suitable for sensors, alarms, Machine-to-Machine (M2M) applications and industrial automation. The ULE technology may also be applied to utility meters and related devices and therefore has implications for the operation of smart grids.
The maximum radio coverage range of DECT ULE will be as wide as standard DECT technology. Smaller coverage may be defined for specific applications due to power consumption and spectrum use considerations.
DECT ULE is based on the DECT base standard (EN 300 175, parts 1 to 8) and it has been designed to be coexistent with other DECT applications (including GAP or NG-DECT). Different types of DECT devices may be used over the same spectrum, and mixed devices supporting DECT ULE and other DECT applications may be built. It is foreseen that the majority of DECT ULE RFPs and some DECT ULE PPs will be mixed devices.
DECT Evolution is a mid-term evolution program intended to enhance DECT by the implementation of a number of technical enhancements, whilst still using the DECT "classic" radio interface:
- Audio enhancements (new codecs, e.g. LC3plus)
- Low latency audio (< 10 ms)
- Enhanced support of advanced chipset features such as higher modulation rates and channel coding
One of the main application areas is high-end and professional audio systems, such as those used by the PMSE industry, where audio streaming with higher data rates and very low latency is essential.
DECT-2020 NR is a Radio Interface Technology (RIT) designed to provide a slim but powerful technology foundation for wireless applications deployed in various use cases and markets.
This radio technology includes, but is not limited to Cordless Telephony, Audio Streaming Applications, Professional Audio Applications, consumer and industrial applications of Internet of Things (IoT) such as industry and building automation and monitoring, and in general solutions for local area deployments for Ultra-Reliable Low Latency (URLLC) and massive Machine Type Communication (mMTC) as envisioned by ITU-R for IMT-2020.
In general, DECT-2020 NR as a technology foundation is targeted for local area wireless applications, which can be deployed anywhere by anyone at any time. The technology supports autonomous and automatic operation with minimal maintenance effort. Where applicable, interworking functions to Wide Area Networks (WAN). e.g. PLMN, satellite, fibre, and internet protocols foster the vision of a network of networks.
DECT-2020 NR can be used as a foundation for:
- Very reliable Point-to-Point and Point-to-Multipoint Wireless Links provisioning (e.g. cable replacement solutions);
- Local Area Wireless Access Networks following a star topology as in classical DECT deployment supporting URLLC use cases; and
- Self-Organizing Local Area Wireless Access Networks following a mesh network topology, which enables to support mMTC use cases.
DECT-2020 NR applies similar design principles as in legacy DECT and DECT ULE. Especially the inherent feature of automatic interference management allows deployments without extensive frequency planning. The Mesh networking capability of DECT-2020 NR enables application-driven network topologies and deployments in e.g. IoT and mMTC use scenarios such that the link budget of classical cellular base-station to user equipment constellations is no longer a limiting factor.
The DECT-2020 NR physical layer is in principle is suited to addressing frequency bands below 6 GHz. The physical layer employs Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) combined with Time Division Multiple Access (TDMA) and Frequency Division Multiple Access (FDMA) in a Time Division Duplex (TDD) communication manner. The physical layer employs multiple numerologies, with different subcarrier spacings and corresponding Cyclic Prefix lengths and FFT sizes, allowing operation with different channel bandwidths, and optimize operations in different frequency bands and propagation environments. The physical layer supports advanced channel coding (Turbo coding) for both control and physical channels and Hybrid ARQ with incremental redundancy, which enables fast re-transmission. Advanced channel coding together with Hybrid ARQ ensures very reliable communication.
Additionally, the physical layer supports, fast link adaptation, transmit and receiver diversity, as well as MIMO operations up to 8 streams.
DECT-2020 NR (i.e. PHY layer numerology and MAC algorithms) is designed to enable coexistence with legacy DECT and DECT evolution in current frequency bands allocated to DECT.
DECT 6.0™ and J-DECT
Two regional variants of the DECT technology have been developed to address the slightly different radio regulation requirements of US and Japan:
DECT in US is working in the 1 920 MHz to 1 930 MHz band and is branded as DECT 6.0. DECT 6.0 is basically identical to DECT with a minor adaptation in the Physical Layer (different frequency and power levels) as required by the FCC. DECT 6.0 operates successfully in the US.
DECT in Japan is working in the 1 894 MHz to 1 904 MHz band and is branded as J-DECT. This frequency allocation is located within the existing Enterprise PHS Systems band and therefore it needs the speciality for the coexistence with PHS Systems to avoid harmful radio interference issues. With regard to the usable part of spectrum the MIC (Ministry of Internal Affairs and Communications, the regulator of Japan) has defined the operating frequency band for J-DECT: emissions of a frequency of 1 895,616 MHz or an integral multiple of 1 728 kHz added to 1 895,616 MHz in a range from 1 895,616 MHz to
1 902,528 MHz shall be used.
DECT registration for the industry
DECT Codes are assigned by ETSI for manufacturers, installers and operators providing for portable parts and fixed parts for DECT.
ETSI keeps the following registrations on behalf of the DECT Industry:
- Equipment Manufacturer's Code (EMC)
- Equipment Installer's Code (EIC)
- Public Operator Code (POC)
- Public Operator Code TRIAL (POC TRIAL).
DECTTM is a registered trademark of ETSI in Europe for the benefit of ETSI members.
A full list of related standards in the public domain is accessible via the DECT committee page.
DECT algorithms are available via ETSI algorithms.