Miscellaneous

DECT Standard: ETS 300 175

DECT Standard: ETS 300 175

The DECT cordless phone system has gain widespread acceptance. Many millions of DECT phones are in use around the world, its use spreading well beyond the boundaries of Europe where it was originally envisaged it would be used, and it is used in well over 100 countries around the globe.

The standard for DECT or Digital Enhanced Telecommunications system was developed by members of the European Telecommunications Standards Institute (ETSI).

The fact that DECT has an agreed standard has been a major element in its success. This has enabled it to be used across a large number of manufacturers, and it enables phones from one manufacturer to operate with equipment from another.

DECT standard

The DECT standard is contained in ETS 300 175 of which there are eight parts, each defining different aspects of the system. The DECT standard, ETS 300 175 consists of a comprehensive set of requirements, protocols and messages. By defining the standard very closely it is possible to achieve interworking reliably not only between handsets and base stations, but also to the telecommuications network itself.

The major sections of the DECT stadanrd ETS 300 175 are defined in the table below:

PartTitleDescription
1OverviewGeneral introduction and overiew to the document detailing the other parts of ETS 300 175 DECT standard.
2Physical layerThis details the radio interface and characteristics for the DECT standard. These include: frequency band, carrier frequency allocation, modulation method, transmission frame structure, transmitted power limits, spurious emission requirements etc.
3Medium Access Control LayerThe MAC section of the DECT standard details the description of procedures, messages, and protocols for radio resource management. These include the link set-up, channel selection, handover, link release and link quality maintenance.
4Data Link Control LayerThis section provides description of provisions to secure a reliable data link to the network layer.
5Network LayerThis details the signalling layer with call control and mobility management functions and protocols.
6Identities and AddressingDescription of the portable and fixed part identities requirements for all DECT application environments.
7Security AspectsThe security is important and it details the methods of ensuring security to prevent eavesdropping, unauthorised access, hacking and fraudulent use.
8TelephonyTelephony requirements for systems supporting the 3.1 kHz speech service to ensure proper interworking with public telecommunications networks. Defines transmission levels, loudness ratings, sidetone levels, frequency response, echo control requirements etc.

DECT standard salient features

This standard defines specification for the system and the way in which it operates. The salient features for DECT are defined below:

DECT standard salient features
ParameterSpecification
Frequency band1880 MHz to 1900 MHz
Access techniqueMC/TDMA/TDD
Symbol rate1152 k Symbol/s
Carrier spacing1728 kHz
Frame duration10 ms
Access channels/RF carrier12 duplex 32 k bit/s channels
Traffic channels/single radioTRX 12
Traffic Channel assignmentInstant dynamic
Control carriersNot required
ModulationGFSK (BT = 0,5) and optional higher level Modulation schemes possible
LO stability25 ppm
Portable average RF power10 mW
Portable peak RF power240 mW 24 dBm
Speech codec32 kbit/s ADPCM
Base Station sensitivity at 0,1 % BER-86 dBm (for GAP)
(typically -90 dBm to -94 dBm)
Basic link budget110 dBm
(Typ.114 dBm to 118 dBm)
Protected 64 kbit/s bearer serviceYes
Base station antennaDiversity Switched. Post detection selection optional
Dual antennas in handset Optional
Tolerance to time dispersion with selection antenna diversity200 ns
(500 ns possible with low-cost non-coherent equalizer)

The DECT cordless phone system is now a well established standard that is widely used for domestic as well as business applications. With the extensions that are now available to the standard, it has become a very flexible system, and this is much of the reason for the success of the DECT cordless phone system.

Wireless & Wired Connectivity Topics:
Mobile Communications basics2G GSM3G UMTS4G LTE5GWiFiIEEE 802.15.4DECT cordless phonesNFC- Near Field CommunicationNetworking fundamentalsWhat is the CloudEthernetSerial dataUSBSigFoxLoRaVoIPSDNNFVSD-WAN
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