DECT or Digital Enhanced (formerly European) Cordless Telecommunications is an ETSI standard for digital portable phones, commonly used for domestic or corporate purposes. DECT can also be used for wireless data transfers. DECT is recognised by the ITU as fullfilling the IMT-2000 requirements and thus qualifies as a 3G system, as a part of the IMT-2000 group of technologies, DECT is also referred to as IMT-FT (Frequency Time). The European Telecommunications Standards Institute (ETSI) is a standardization organization of the telecommunications industry (equipment makers and network operators) in Europe, with worldwide projection. ... A portable phone or cordless phone is a wireless telephone which is associated with a fixed telephone landline (POTS) and can only be operated close to (typically less than 100 metres of) its base station, such as in and around the house. ... This article is about the location. ... IMT-2000 (International Mobile Telecommunications-2000) is the global standard for third generation (3G) wireless communications as defined by the International Telecommunication Union. ... It has been suggested that Evolution to 3G be merged into this article or section. ... IMT-2000 (International Mobile Telecommunications-2000) is the global standard for third generation (3G) wireless communications as defined by the International Telecommunication Union. ... IMT-2000 (International Mobile Telecommunications-2000) is the global standard for third generation (3G) wireless communications as defined by the International Telecommunication Union. ...

The base unit and handset of a British Telecom DECT cordless telephone

Download high resolution version (750x686, 107 KB)For information on computer-based games in general, see computer and video games. ... Download high resolution version (750x686, 107 KB)For information on computer-based games in general, see computer and video games. ... BT Group plc (which trades as just BT, and is commonly known by its former name, British Telecom) is the privatised former British state telecommunications operator. ...

Features

Typical abilities of a domestic DECT Generic access profile (GAP) system include: In DECT, the Generic Access Profile (GAP) is the basic DECT profile and applies to all DECT portable and fixed parts that support the 3. ...

• Multiple handsets to one base station and one phoneline socket. Additional handsets usually have a battery charger station instead of a base station. No need for additional telephone sockets nor additional transceivers.

• Interference-free wireless operation to around 100 metres outdoors. Operates clearly in common congested domestic radio traffic situations. For instance, generally immune to interference from WiFi or video senders.

• Ability to transfer a call between handsets, or to have multiple handsets talking on the same call.

• Ability to make internal (intercom) calls between handsets (for example, to call from the bedroom to the kitchen).

Many DECT systems also include additional features such as Caller ID or a shared phonebook, but these are unstandardized and may not work across different handset types. The BT Home Hub supports DECT telephones. Wi-Fi (or Wi-fi, WiFi, Wifi, wifi), short for Wireless Fidelity, is a set of standards for wireless local area networks (WLAN) currently based on the IEEE 802. ... A video sender is a device for wirelessly transmitting domestic video signals from one room to another. ... Caller ID (Caller Identification or CID, and more properly Calling Number Identification -- CNID) is a telephony intelligent network service that transmits the callers telephone number and (in some places) the callers name to the called partys telephone equipment during the ringing signal or when the call is... The BT Home Hub with BT Hub Phone. ...

Technical details

Some DECT properties:

• audio codec: G.726
• net bit rate: 32 kbit/s
• frequency: 1880-1900 MHz in Europe, 1920-1930MHz in the US
• carriers: 10 (1880..1900 MHz)
• timeslots: 2 x 12 (up and down stream)
• channel allocation: dynamic

DECT physical layer uses: G.726 is ITU-T speech codec operating at bit rates of 16-40 kbit/s. ... A megahertz (MHz) is one million (106) hertz, a measure of frequency. ... This article or section does not cite its references or sources. ...

• Frequency division multiple access (FDMA),
• Time division multiple access (TDMA) and
• Time division duplex (TDD)

This means that the radio spectrum is divided into physical channels in two dimensions: frequency and time. FDMA, or frequency-division multiple access, is the oldest and most important of the three main ways for multiple radio transmitters to share the radio spectrum. ... Time division multiple access (TDMA) is a channel access method for shared medium (usually radio) networks. ... Duplex is the having of two principal elements or parts. ... Radio frequency, or RF, refers to that portion of the electromagnetic spectrum in which electromagnetic waves can be generated by alternating current fed to an antenna. ...

The maximum allowed power for portable equipment as well as base stations is 250mW. On average, however, a portable device radiates about 10mW during a call as it is only using one of 24 timeslots to transmit.

DECT media access control layer is the layer which controls the physical layer and provides connection oriented, connectionless and broadcast services to the higher layers. It also provides encryption services with the DSC Cipher (DECT Standard Cipher). media access control is where people try to access a control to the media. ... A connection-oriented networking protocol is one which identifies traffic flows by some connection identifier rather than by explicitly listing source and destination addresses. ... In a packet-switched network, connectionless mode transmission is transmission in which each packet is prepended with a header containing a destination address sufficient to permit the independent delivery of the packet without the aid of additional instructions. ... Wikibooks has more about this subject: Marketing Note: broadcasting is also a term for hand sowing. ... This article is about algorithms for encryption and decryption. ...

DECT data link layer uses a variant of the ISDN data link protocol called LAPC. They are based on HDLC. To meet Wikipedias quality standards, this article or section may require cleanup. ... Integrated Services Digital Network (ISDN) is a circuit-switched telephone network system, designed to allow digital transmission of voice and data over ordinary telephone copper wires, resulting in better quality and higher speeds than that available with the PSTN system. ... It has been suggested that the section HDLC from the article Measuring_data_throughput be merged into this article or section. ...

DECT network layer contains various protocol entities: The network layer is level three of the seven level OSI model. ...

• Call Control (CC)
• Call Independent Supplementary Services (CISS)
• Connection Oriented Message Service (COMS)
• Connectionless Message Service (CLMS)
• Mobility Management (MM)

All these communicate through a Link Control Entity (LCE).

The call control protocol is derived from ISDN DSS1, which is a Q.931 derived protocol. Many DECT specific changes have been made. ISDN is also short for isosorbide dinitrate Integrated Services Digital Network (ISDN) is a type of circuit switched telephone network system, designed to allow digital (as opposed to analog) transmission of voice and data over ordinary telephone copper wires, resulting in better quality and higher speeds, than available with analog... Digital Subscriber System No. ... The ITU-T Recommendation Q.931 is ISDNs connection control protocol, roughly comparable to TCP in the Internet Protocol stack. ...

There are four application areas in use in Europe:

• Domestic DECTs are connected to a base (radio fixed parts) connected to the PSTN. A base can accept more DECT handsets.
• Business DECTs connected to PBX. In such cases, many radio fixed parts. The DECT handsets dynamically connect to these (hand over feature)
• Public DECT connected to the PSTN (very rare). A high density alternative to GSM.
• Local loop (very rare). In this case, a DECT radio link replaces the normally wired connection between the final PSTN distribution point to the subscriber.

DECT GAP is an interoperability profile for DECT. The intent is that two different products from different manufacturers that both conform not only to the DECT standard, but also to the GAP profile defined within the DECT standard, are able to interoperate for basic calling. In other words, any phone that supports GAP can be registered with any base station that also supports it, and be used to make and receive calls. They will not necessarily be able to access advanced features of the base station, such as remote operation of an answering machine built into the base. Most consumer-level DECT phones and base stations support the GAP profile, even ones that do not publicise this feature, and thus can be used together. The public switched telephone network (PSTN) is the concatenation of the worlds public circuit-switched telephone networks, in much the same way that the Internet is the concatenation of the worlds public IP-based packet-switched networks. ... PBX redirects here. ... In telecommunications, the local loop is the wiring between the central office (telephone exchange in British English) and the customers premises demarcation point. ... In DECT, the Generic Access Profile (GAP) is the basic DECT profile and applies to all DECT portable and fixed parts that support the 3. ... An answering machine, also known as an answer machine (especially in UK and British commonwealth countries), ansafone (tradename [1]), ansaphone (tradename [2]), answerphone or telephone answering device (TAD), is a device for automatically answering telephone calls and recording messages left by callers when the party called is unable to answer...

DECT was developed by ETSI but has since been adopted by many countries all over the world. DECT is used in all countries in Europe, outside Europe it is used in most of Asia, Australia and South-America. As of 2005, the American Federal Communications Commission changed channelization and licensing costs in a portion of 1900 MHz range spectrum which allowed DECT devices to be used without expensive changes. DECT will operate as Unlicensed Personal Communications Services (UPCS). The FCCs official seal. ...

See also

• Generic access profile (GAP)
• GSM Interworking Profile (GIP)
• CorDECT
• Unlicensed Personal Communications Services
• Wireless local loop
• Microcell
• CT2 (DECT's predecessor)
• WDECT

In DECT, the Generic Access Profile (GAP) is the basic DECT profile and applies to all DECT portable and fixed parts that support the 3. ... The GSM Interworking Profile, usually abbreviated to GIP and sometimes to IWP, is a profile for DECT that allows a DECT base station to form part of a GSM network, given suitable handsets. ... corDECT is a wireless local loop standard developed in India by Indian Institute of Technology - Chennai under leadership of Prof Ashok Jhunjhunwala, based on the DECT digital cordless phone standard. ... Unlicensed Personal Communications Services operate in the 1910-1930 MHz and 2390-2400 MHz frequency bands and are used for short range applications. ... Wireless local loop (WLL), also called Broadband Wireless Access (BWA) radio in the loop (RITL) or fixed-radio access (FRA) or fixed-wireless access (FWA) or Fixed Wireless Terminal (FWT), is the use of a wireless communications link as the last mile / first mile connection for delivering plain old telephone... Microcell Telecommunications is a Canadian wireless PCS telecommunications service provider. ... CT2 is a cordless telephony standard that was used in the early nineties to provide short-range proto-mobile phone service in some countries in Europe. ... Wideband Digital Enhanced Cordless Telecommunications or simply WDECT is similar to DECT except that it is a frequency hopping protocol. ...

External links

• DECT Forum at dect.org
• DECT information at ETSI
• DECTWeb.
• DECT Overview.
• The DSC Cipher posted in a newsgroup in 2002.