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 unlicensed frequency allocations world-wide.
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. DECT is also used in the Wireless Local Loop to replace copper in the 'last mile' for user premises.
DECT is the second most successful ETSI standard after GSM. The accumulated number of DECT devices manufactured from the beginning reaches 820 million with a growing ratio of 100 million devices per year. DECT dominates the wireless voice applications with a market share of 73% for all cordless technologies (including analogue and proprietary). No other cordless technology can compete with DECT in world-wide acceptance, interoperability, and capability of the standard for telephony (PSTN and VoIP) applications.
DECT is gaining market share due to the replacement of old analogue technologies and the reduction of market share of digital technologies based on voice over IEEE 802.11. The reduced cost of DECT chipsets due to mass production also allows DECT to enter in the market of replacement of wired fixed phones.
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. The standard now includes wideband and super-wideband codecs and detailed audio specifications (defining parameters such as audio levels, equalization masks and echo cancellation). This makes possible the achievement of real interoperability from an end user perspective. Finally, DECT ULE (Ultra Low Energy) has been developed to open the technology to the M2M market.
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 unlicensed 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 allocations in Europe of 1 900 MHz to 1 920 MHz (shared with UTRAN TDD), 1 920 MHz to 1 980 MHz (shared with the uplink of UTRAN FDD) and 2 010 MHz to 2 025 MHz have been foreseen by IMT-2000 for potential expansion of the standard, but actually they are not used yet.
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) and regional variants.
The New Generation DECT
New Generation DECT (NG-DECT) is the name given to the further development of the DECT standard performed since 2006 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.
DECT Forum has coined the term "CAT-iq," as a commercial brand for NG-DECT products. From a technical perspective both terms have identical meaning. CAT-iq also includes a certification program to ensure technology compliance with the NG-DECT standards, enforcing the compliance with the detailed testing standards developed by TC DECT.
New Generation DECT includes the following features:
- Superior voice quality better than any existing technology (Wideband and super-wideband Speech)
- New codecs G.722, G.729.1 and MPEG-4
- Improved audio models (including acoustic interface) jointly developed with the participation of audio experts
- Complete set of signalling and procedures for VoIP (SIP and H.323) and mixed (base stations with dual PSTN and VoIP connectivity) scenarios supporting features such as multiple lines, multiple calls, call line and name identification, call transfer, conferencing, intrusion call, etc.
- New DECT headset devices (with DECT radio i/f)
- Support of Broadband Data and Audio Streaming
- Video telephony capability
- Streaming CD Quality Audio Content
- Home Monitoring, Door phone, Baby monitor, Mailbox
- Plug & Play functionality of all components
- Enhanced security
- Automatic device detection and configuration (easy pairing)
- Complete testing specifications
- Software update over the air (SUOTA) for handsets and other cordless devices
- List access services (LAS) for convenient exchange of call lists, like incoming call list
New Generation DECT specifications started to appear in March 2007, with the publication of an Overview Report (TR 102 570). Other New Generation DECT documents 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. Examples of applications include the following:
- Actuator devices
Devices with fast response times (Fixed Part to Portable Part and vice versa) commonly used, for instance, in electricity plugs or motor drivers such as a sunscreen
- Slow Actuator devices
Devices with relatively fast response times (Fixed Part to Portable Part and vice versa) commonly used, for instance, in thermostats
- Sensor devices
Devices with long sleep times and fast response times from Portable Part to Fixed Part. Typical examples are smoke detectors and motion detectors
The ULE Alliance has also established certification programs for Home Automation Networks based on ULE technology.
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 (Gaussian Frequency Shift Keying (GFSK)):
- 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 is a major new standardization activity, with the intention of meeting some of the requirements of Recommendation ITU-R M.2410, specifically Ultra-Reliable Low Latency Communications (URLLC) and Massive Machine-Type Communications (mMTC).
To meet the requirements, OFDM, FEC, MIMO and HARQ are used to allow much higher data rates, lower latency and reliability compared to legacy DECT.
The following three major application areas have been identified as target for DECT-2020 radio technologies:
- Home and Building Automation, including Smart Living.
- Industry automation - Factories of the Future, Industry 4.0.
- Media and entertainment industry - Programme Making and Special Events (PMSE)
Nevertheless, DECT-2020 application areas will not be restricted to these three major domains and additional applications and use cases may be supported. In particular, any Machine Type Communication, including massive M2M are considered candidate areas for the technology.
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.