A DECT Wireless headset (or as they are sometimes known, CORDLESS) works using the ETSI "Digital Enhanced Cordless Telecommunications" (i.e. DECT) standard.
DECT is a digital cellular system like mobile phones. A major difference between the systems is the cell radius — DECT cells have a radius of 25 to 100 metres, while GSM cells are 2 to 10 km. DECT operates in the 1900 MHz band. Being digital it provides a secure, crystal clear signal
Back in the early 1980's, when analogue cordless phones began to reach European shores from the Far East, the techies quickly cottoned on to the fact that if you did it 'digitally' it could be better - less crackle and interference, more phones within a small space, security against eavesdroping, the ability to move throughout buildings by 'handing over' between 'base stations', and more.
By late 1987, two erstwhile technologies had emerged aspiring to this role - the UK CT2 standard and the Swedish CT3. In the true spirit of European compromise it was decided by ETSI - the European Telecommunications Standards Institute, to develop a new standard - DECT - which would take the best of CT2 and CT3 and go far beyond either. Thus, in January 1988, was DECT born.
The initial market success for DECT was found in Germany, where DECT domestic cordless telephone products found themselves competing on price against products designed to the analogue CEPT standard and winning. Today DECT products are taking over 60% of this market. As technology costs and product prices fell and as production volumes ramped up so DECT domestic phones began to be marketed and to find market success in other European countries. As well as the mainstream telecomms manufacturers, second and third tier manufacturers from the Far East have now entered the market.
The second early market success for DECT was in the wireless PABX application. A typical office, factory or warehouse has many telephones distributed throughout the premises all connected by wires back to the on-premises switchboard, the PABX. The DECT wireless PABX provides an alternative that offers much greater flexibility - a small number of radio basestations are wired back to the PABX instead and cordless handsets communicate, by radio, to these basestations.
The Dect Forum announced, on the 19 January 2006, the next generation of DECT wireless telephony - "DECT 6.0 - Interference Free Communication". The fixed telephony network is migrating to a new generation of IP based networks and services. Therefore DECT is moving to a new generation of value added IP based services.
To say a device is based on DECT 6.0 technology means it is certified to operate in the Unlicensed Personal Communications Services (UPCS) radio band in the United States. It uses a communication protocol (spectral etiquette) defined by the DECT Forum technology group (see www.dect.org for more information).
The DECT 6.0 communications protocol is based on the European DECT standard defined by ETSI (European Technology Standards Institute), slightly modified to comply with the regulatory requirements for the UPCS spectral etiquette, and for operating in the 1920 – 1930MHz band instead of the 1880–1900MHz band specified for Europe and countries sharing frequency bands with the European allocations. The equivalent designation in Canada is LE-PCS, for License-Exempt Personal Communications Service.
Because the FCC has reserved the 1.9GHz frequency band for only DECT communication devices, and because the DECT standard requires devices to actively avoid interference within the band to receive certification, the result is a clear frequency that is optimal for voice communication. To that end, all equipment approved for the 1.9GHz band must implement a “listen before transmit” spectrum-sharing etiquette. Interference manifests as pops, clicks or blanks noticeable to headset users, and occurs when two headsets share the same radio channel and timeslot. By changing channels when interference occurs, and by checking for interference before changing channels, DECT devices prevent interference.
The DECT Forum expects that DECT 6.0 products will start to rollout in 2006. Indeed, Plantronics , Jabra & Sennheiser have already announced their new generation of DECT 6.0 products
For DECT wireless headsets click here