Digital Enhanced Cordless Telecommunications
Digital Enhanced Cordless Telecommunications
Wireless - DECT
Bithium is a member of the DECT Forum and ULE Alliance that together help drive and shape the future of the DECT standard. We provide development services for new DECT and DECT ULE designs and have more than 15 years of bringing finalized products to the market and a team with some with members with more than 20 years of experience in some.
The DECT standard is used in digital cordless telephones around the world. It has been defined by ETSI (European Telecommunications Standards Institute) and ITU has adopted it as a member of the IMT-2000 family (called IMT-FT in IMT-2000). It operates on the 1880-1900MHz frequency band in Europe and on the 1920-1930MHz in USA and Canada (there the DECT 6.0 variant is used). DECT 6.0 uses the same general structure and techniques with MAC layer different approaches. The DECT bands are reserved for exclusive use by DECT devices. That is a key advantage of the technology when compared to those using ISM bands. It means that a reliable and robust cordless communications can be achieved reducing interference behavior is well understood as it uses the same standard.
DECT stands for Digital Enhanced Cordless Telecommunications. It is the most adopted standard for digital cordless telephony in Europe and around the world, having been defined by ETSI (European Telecommunications Standards Institute) back in 1992 for supporting both voice and data services. Its characteristics make it particularly suitable for applications requiring good reliability and resilience to interference that are coped by its dynamic channel allocation and FDD and TDMA structure.
The standard describes the common radio interface. Different physical and MAC requirements apply to different allocated frequency bands depending on the world region of interest.
DECT Frequencies Worldwide
ITU has adopted DECT as a member of the IMT-2000 family (called IMT-FT in IMT-2000).
The standard is used in different world regions in different frequency bands and with different requirements in terms rules of access to the radio resources.
- 1880 – 1900 MHz - In Europe, South Africa, Hong-Kong and Australia
- 1920 – 1930 MHz - In the United States and Canada (DECT 6.0)
- 1910 – 1920 MHz - In Brazil
- 1894 – 1906 MHz (J-DECT) in Japan
DECT 6.0 uses the same general structure and techniques with MAC layer different approaches. DECT 6.0 is also used in Brazil although in a different frequency band.
The DECT bands are in some of the above mentioned regions reserved for exclusive use by DECT devices. That is a key asset of the technology that enables it to provide reliable and robust cordless communications because potential interfere behavior is well understood as it uses the same standard.
The DECT standard has a number of profiles for different applications, in particular:
- GAP - General Access Profile
It is used on most of the DECT residential telephone systems available in the market today. It provides interoperability with devices (PPs and FPs) in the voice communications telephony field area from different manufacturers.
Bithium works with different application profiles. It may also build custom profiles to fit customer specific application and interoperability requirements. Please consult us for specific questions you may have on this.
- DPRS - DECT Packet Radio System
DPRS is the standard for Packet Data communications over DECT.
- DMAP - DECT Multimedia Profile
DMAP combines GAP and DSPRS under a single standard.
For more information on the DECT standard capabilities, profiles we can provide and profiles please contact us.
DECT is the base of other standards as listed below.
- CAT-iq - Cordless Advanced Technology by the DECT Forum based on the NG-DECT standard series
CAT-iq is based on the DECT standard and provides a standardized way in interfacing VoIP and internet connectivity to DECT cordless terminals. It also brings wideband audio and advanced service capabilities. ETSI and the DECT Forum and its members are responsible for CAT-iq standardization and interoperability.
- DECT ULE – DECT Ultra Low Energy
- DECT ULE powers low-energy sensors and actuators with the range and allocated frequency spectrum advantages of DECT.
Buthium is an active participant with the ULE Alliance on the development of the DECT ULE HAN-FUN protocol. This protocol serves as the basis of compatibility between devices of different vendors. Information on the certification program can be found in this link.
DECT uses a star topology as depicted in the image below. The central-element of a system is designated as Fixed Part (FP) – this is typically the base station in a residential DECT system. The handsets, headsets or other form of device that communicates using DECT with the Fixed Part are designated as Portable Parts (PP).
A multi-carrier TDMA/TDD structure is used allowing a number of simultaneous communications to the same base to take place. Up-to 120 simultaneous ongoing communications are theoretically possible at the same location.
This is the most well-known service, used on residential and business telephone systems
- Wideband audio (8KHz)
Wideband audio was introduced with CAT-iq 1.0. It provides enhanced audio quality to communications over DECT. One can, however, only feel the improved quality if there is no other botleneck in the system using it. It is particularly suited for systems with VoIP interfaces as the end-to-end audio quality can be better than that of the POTS (Plain Old Telephone System).
- Ultrawideband audio (16KHz)
This service is based on the transfer of audio coded with the CELT codec. Bithium will be offering problem solving solutions supported on this type of DECT service.
Data services include low-data-rate data (2kbit/s), as well as protected (24kbit/s) or unprotected synchronous (32kbit/s). Multiples of these two last data-rates are also possible using multiple slots.
The link budget of a DECT equipment is typically~116dB. This typically provides a range of~250m (~820 feet) in line of sight conditions and ~30m (~98 feet) indoors (note: this indoor range is highly dependent on the number of walls, wall thicknesses, metal furniture, construction materials, etc.
Why to use DECT in a new product?
If you need a reliable voice or audio cordless product this is most probably the right technology for it as it uses reserved bands therefore reducing the chances of interference from devices working in accordance with a different standard (as is the case in the 2,4GHz band).
DECT includes authentication and cyphering mechanisms that make it a safe approach for wireless communications as compared with any analogue option. The security options include the standard cyphering algorithm or alternative proprietary solutions for additional security.
How can Bithium help me develop a DECT product?
We can provide a turnkey development solution from concept to ready product or help on any of the steps in between. The product can range from a residential telephone system, to a multi-cell system with interconnectivity through an IP network. It really depends on what is the best way to interact with your company team. We have our own field proven DECT protocol stack which we use to design challenging and innovative projects in the DECT field.
Why should I chose Bithium for my next design?
Bithium is an experienced, European based company with a track record of successful designs that we assisted in bringing to the market. We take pride on the innovation and success we help bring to our customers by developing innovative reliable products. We have a extensive accumulated experience in DECT and a spirit ready to new challenges.
Why are you using your own protocol stack?
Bithium uses its own in-house developed, market proven DECT protocol stack. The stack has different add on capabilities. Furthermore it may be tailored to suit particular requirements therefore bringing a great flexibility for product development and optimization.