Aussie Phone Brokers - Telecommunications Glossary
'D' Glossary Terms
- DA - Directory Assistance
- Operator-assisted (or possibly a CVR-assisted) telephone directory service which provides the user the phone number of a residence or business. Number must be listed in the telephone directory.
- Data Transmission
- Transmission of data between two points of a network.
- DCITA - Department of Communications, Information Technology and the Arts
- Resources and news about telephone, Internet, broadband and ICT services for consumers and for business: funding, policy, legislation, reviews, online security and contacts for industry bodies.
See also: ACMA - DDSO - Digital Data Service Obligation
- The digital data service obligation (DDSO) is the obligation placed on a digital data service provider to ensure that digital data services are accessible to all people in Australia on an equitable basis, wherever they reside or carry on business. The DDSO has two parts - the general DDSO for people in urban areas and the special DDSO for people in regional service areas. Services must operate at a specified minimum speed of approximately 64kbps.
- Decibel (dB)
- A logarithmic measurement unit that describes a sound's relative loudness or the relative difference between two power levels. A 10dB difference is required to double the subjective volume. A 3dB difference equates to a doubling of power.
- DECT - Digital Enhanced Cordless Telecommunications
- Used for phone handsets and data, this wireless technology has a range of up to a few hundred meters. DECT can support multiple handsets and may be incorporated into an existing phone system.
- Desktop Conferencing
- Conferencing through a PC or laptop, often with a video component. Desktop conferencing may occur between two or more parties. Limitations are available bandwidth, software and the PCs' hardwares.
- Dial Tone
- Sound provided by local switch to confirm connection and ready status to the user.
- Dial-up
- A non-broadband Internet connection to an ISP. The connection is made by a modem dialling the ISP through the traditional PSTN network.
- Dial-up Speed
- Bandwidth description of the connection speed of a dial-up connection. Typical speeds are 14Kbps to 56Kbps.
Related: Broadband, Broadband - DID - Direct In Dial
- The use of a 100 InDial Range with a PABX, which allows an outside caller to dial a phone number that will ring directly to a specific party instead of calling a main phone number. The PABX must be programmed to assign that number to a specific extension.
See also: PABX - Digital
- The representation of information using discrete elements called binary code. In everyday use (especially in voice communications) digital signals are used to represent analog information. Digital signals are useful because they can represent analog signals, can be easily handled by computer systems and networks (themselves, digital systems), can be compressed, and do not degrade with reproduction.
- Digital Certificates
- Electronic authorisation tools used to identify users and resources over network connections. Heavily used on the Internet to verify identity of users and webpages.
- Digital Compression
- Mathematical technique for modifying/representing a digital signal. The compressed signal will be smaller than the original. Information can therefore be sent faster over the same bandwidth.
- Digital Signals
- The representation of analog signals in digital format, called digital signals.
- Digital Subscriber Line
- Use of an existing 'subscriber line' (traditional phone line) to deliver digital data at broadband speeds. The local exchange (where the copper loop telephone line is connected) must be 'enabled' with DSL technology.
Related: ADSL, SHDSL - Direct Dialling
- Previously direct dialling was the event of dialling an intended party without the aid of an operator. Nowadays, Direct Dialling is still commonly used in two circumstances. IDD (International Direct Dialling) is connection to an international destination without the aid of an operator. IDD is still in use in vernacular because pricing structures quote IDD rates. The second common use for Direct Dialling is for Direct In Dialling (called 'Direct Dialling In' by the Brits). Direct In Dialling is where a phone system (PABX) can recognise an incoming dialled number, bypass the main answering point (eg. the receptionist), and pass the call directly to the correct extension. DID usually requires a 100 number range.
Related: DID - Directory Assistance
- Operator-assisted (or possibly a CVR-assisted) telephone directory service which provides the user the phone number of a residence or business. Number must be listed in the telephone directory.
- DNS - Domain Name Server
- A server which translates the URL of a website into its actual numeric IP address. When a browser requests a web page, the domain name server is consulted for the actual IP address. Humans use words to define web addresses, computers use numeric IP addresses.
- Domestic Call
- A call within Australia.
Related: STD - Drop Out
- The accidental disconnection of a phone call. Applies to both Fixed Line services (including VoIP) and Mobile Services. VoIP users also call partially missing words a 'drop-out'.
- DSL - Digital Subscriber Line
- Use of an existing 'subscriber line' (traditional phone line) to deliver digital data at broadband speeds. The local exchange (where the copper loop telephone line is connected) must be 'enabled' (implementation of hardware) to allow data transmission using the DSL.
Related: ADSL, SHDSL - DSLAM - Digital Subscriber Line Access Multiplexer
- Also called a Digital Subscriber Line Access Module or a MUX. This is a hardware interface between DSL lines and a network 'backbone'. DSLAMs are located in the local exchange. DSLAMs also provide the interface for ULL supply of voice/Internet connections - these Internet connections are usually faster than normal ADSL connections.
- Dual Band
- Refers to a communication device that works at two different frequencies (or bands). Commonly, a Dual Band phone is a mobile phone which operates on both the 900MHz and 1800MHz frequency bands. During network congestion, a dual band phone can use its alternate frequency to provide a connection. See also Tri-Band. See also Quad-Band. Not to be confused with a Dual Mode handset.
- Dual Mode
- The ability of a mobile handset to operate on both the analog and digital networks; even to the extent of using the same frequency band.
- Duplex
- The ability for both ends of a communication to send and receive data. Telephones are a Duplex communication because both parties can talk at the same time; 2-way radios are half-duplex because only one party can talk at any one time.
These pages contains commonly used terms and their definitions for the Australian telecommunications industry. The terms found here refer to the ICT industry (Information and Communication Technology), IT industry (Information Technology) and the general Telecommunications Industry - including Mobile Telecommunications, Fixed Line services and IP telecommunications.
Please use the index below:
0-9 : A : B : C : D : E : F : G : H : I : J : K : L : M
: N : O : P : Q : R : S : T : U : V : W : X : Y : Z