Information AboutDect |
| CATEGORIES ABOUT DIGITAL ENHANCED CORDLESS TELECOMMUNICATIONS | |
| local loop | |
| broadband | |
| mobile telephony standards | |
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DECT or '''Digital Enhanced (formerly European) Cordless Telecommunications''' is an ETSI standard for digital Portable Phone s, commonly used for domestic or corporate purposes. DECT can also be used for wireless data transfers. DECT is recognised by the ITU as fulfilling the IMT-2000 requirements and thus qualifies as a 3G system. Within the IMT-2000 group of technologies, DECT is referred to as IMT-FT (Frequency Time). DECT cordless telephone]] 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). FEATURES Typical abilities of a domestic DECT Generic Access Profile (GAP) system include:
Many DECT systems also include additional features such as Caller ID or a shared phonebook, but these are not standardized and may not work across different handset types. TECHNICAL DETAILS Some DECT properties:
The DECT Physical Layer uses:
This means that the Radio Spectrum is divided into physical channels in two dimensions: frequency and time. 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 time slots to transmit. The 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). The DECT Data Link Layer uses a variant of the ISDN data link protocol called LACP . They are based on HDLC . The DECT Network Layer always contains the following protocol entities:
Optionally it may also contain others:
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. There are four application areas in use in Europe:
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. SEE ALSO
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