Introduction
DECTTM technologies are designed for local area wireless communications, which can be adapted for many applications and can be used over licence exempt frequency allocations as well as over licensed International Mobile Telecommunications (IMT) frequencies.
The DECT-2020 New Radio (NR) standard series is part of the IMT-2020 technology family and the classic DECT standards series is part of the IMT-2000 technology family.
DECT-2020 NR is developed to address the future digitalization needs and it is optimized for local area wireless applications, which can be deployed anywhere by anyone at any time. These technologies can be adapted for many applications supporting digitalization such as industry 4.0, utility and public services, audio and media industry use. Autonomous operation and device to device direct communication enable reliable communication networks. DECT-2020 NR supports a wide range of applications which could operate below 6 GHz frequencies in unlicensed and licensed spectrum.
Classic DECT supports applications such as home and enterprise voice applications, low latency professional audio and Smart Home applications.
DECT technologies are developed as European standards and they are also adopted by many other countries, including the US and many countries in Latin America and the Asia-Pacific region. This has made classic DECT the worldwide de-facto standard for cordless telephony application
Dedicated spectrum
The commonly used spectrum allocation in Europe is 1 880 MHz to 1 900 MHz. This spectrum is licence 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 (Unlicensed Personal Communications Service) band. In this case, the allocation is not technology exclusive, but is in practice "clean" enough to achieve similar interference-free operation.
Our Role & Activities
Technical Committee DECT
Within ETSI, Technical Committee DECT (TC DECT) is responsible for developing and maintaining the portfolio of DECT standards. Today there are two groups of standards, one group is for the original or “classic” DECT technology and the other one is the recently-added DECT-2020 NR (New Radio).
Most of the activities within TC DECT are on the new standard DECT-2020 NR but the classic DECT standards are also maintained and improved on an ongoing basis.
DECT-2020 NR
DECT-2020 NR standards (TS 103 636 parts 1 to 5) are developed to address the future digitization needs optimized for local area wireless applications, which can be deployed anywhere by anyone at any time. These technologies can be adapted for many applications supporting digitization such as industry 4.0, utility and public services, audio and media industry use. They support a wide range of applications which could operate below 6 GHz frequencies in unlicensed and licensed spectrum.
DECT-2020 NR technology is part of the IMT-2020 technology family in the ITU (International Telecommunication Union). It is the latest development in ETSI DECT, providing very reliable and low latency radio communication for massive Machine Type Communication (mMTC) and for Ultra Reliable and Low Latency Communication for local networks. DECT-2020 NR is designed to support various Industry and Utility applications as well as supporting PMSE (Program Making and Special Events) and voice use cases.
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 is a component RIT of the ITU recommendation ITU-R M.2150, which contains technologies fulfilling IMT-2020 requirements.
This radio technology supports all kinds of applications including, but 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 indoors and outdoors 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 at 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 (Public Land Mobile Network), 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 classic DECT deployment supporting URLLC use cases; and
- Self-Organizing Local Area Wireless Access Networks following a mesh network topology, which enables mMTC use cases to be supported.
DECT-2020 NR applies similar design principles as in classic 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 scenarios such that the link budget of classic cellular base-station to user equipment constellations is no longer a limiting factor.
The DECT-2020 NR physical layer is in principle 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 optimizing 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 (Admission ReQuest) 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 and transmitter and receiver diversity, as well as MIMO operations up to 8 streams.
DECT-2020 NR (i.e. Physical layer numerology and Medium Access Control algorithms) is designed to enable coexistence with classic DECT and DECT evolution in the frequency bands currently allocated to DECT.
An evaluation of ETSI DECT-2020 NR technology can be found in TR 103 810.
Classic DECT
The original or “classic” DECT standard was developed with a focus on voice, messaging and networking applications. It offers a range up to 500 metres and is used in dedicated licence-exempt frequency allocations in many countries around the world.
DECT dominates the cordless residential market and the enterprise PBX (Private Branch eXchange) market. The capability of the standard for telephony applications is unrivalled by any other technology. In addition to a complete repertoire 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.
The classic DECT standard was first developed in the era of PSTN (Public Switched Telephone Network) and ISDN (Integrated Services Digital Network) and made to be compatible with the standards and protocols relevant at that time. Over the many years of its existence DECT has been enhanced and adapted to answer to new market developments such as the migration to VoIP and the advent of Home Gateways (giving rise to New Generation DECT), the need for Smart Home solutions (leading to the DECT Ultra Low Energy standard) and DECT Evolution to address low-latency applications in Professional Audio.
On top of this, DECT has developed regional variants such as DECT 6.0 for the US, J-DECT for Japan and K-DECT for the South Korean market.
New Generation DECT
New Generation DECT (NG-DECT) is the name given to the development of the DECT standard primarily targeted on VoIP applications. NG-DECT is implemented by the addition of new functions to the DECT base standard (EN 300 175, parts 1 to 8, keeping backwards-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 interface)
- 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
More information on New Generation DECT can be found in TS 102 527 parts1-5.
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 can be built. DECT ULE is specified in TS 102 939-1 and TS 102 939-2.
DECT Evolution
DECT Evolution is a mid-term evolution program intended to enhance DECT by the implementation of a number of technical enhancements, whilst still based on the classic DECT base standards (EN 300 175, parts 1 to 8):
- 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. Related specifications are TS 103 634 (LC3plus) and TS 103 706 (Advanced Audio Profile).
DECT 6.0™, J-DECT™ and K-DECT
Three regional variants of the DECT technology have been developed to address the slightly different radio regulation requirements of US, Japan and South Korea:
- DECT in the US uses 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. Details can be found in TS 102 497.
- DECT in Japan uses the 1 894 MHz to 1 905 MHz band and is branded as J-DECT. This frequency allocation is located within the existing Enterprise PHS Systems band and therefore it needs special provision for 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 1895,616 MHz in a range from 1895,616 MHz to 1904,256 MHz shall be used. Details can be found in the ARIB standard STD-T101.
- DECT in South Korea (K-DECT) uses the 1 786 MHz to 1 792 MHz band.
Other Services
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.
Standards
A full list of related standards in the public domain is accessible via the DECT committee page.
DECT algorithms are available via ETSI algorithms.