Traditional terminal that does not receive and send digital signals, i.e. precisely defined signals, but rather analog oscillations.

The customer uses a special telephone number, which he requests from a call-back provider, to call up a central computer (e.g. in the USA). This calls the customer back, places an exchange line at the customer's disposal and the actual number can now be dialled.

Call filters provide the possibility to select incoming calls and to handle them in accordance with defined criteria. Calls can be rejected, transferred directly to the answering machine or the engaged (busy) signal can be switched on.

During a telephone conversation, an acoustic signal indicates that another party is calling.

Call-by-call means that a special carrier prefix is used so that for each individual call a specific network operator (carrier) can be selected. In some cases, call-by-call calls have to be registered with the carrier.

Prepares a list of all incoming calls that were not answered.

The calling subscriber transmits their number and the called subscriber sees it on the telephone display.

If the subscribers own number is not to be sent, i.e. it is not to be displayed on the telephone of the called party, this service can be subscribed to with the network operator.

Organisation or company that operates a telecommunications network, i.e. has control of all the activities related to network management.

Transmission process used in UMTS, the GSM replacement technology. CDMA encodes the radio signal using a digital code and transmits this in a broad frequency range. This allows transmission rates of up to a maximum of 2 Mbit/s to be achieved, while in the current GSM networks the upper limit is 9.6 kbit/s.

With channel trunking, two channels are used which means that two connections are required simultaneously. This is particularly advantageous with online applications since twice the ISDN transmission rate is available (128,000 bit/s).

A plastic card with an integrated microprocessor that can be used in many applications.

If a called subscriber is busy, the Completion of Calls to Busy Subscriber feature can be activated. As soon as the number is no longer engaged, the ISDN telephone generates a special ringing tone.

Permits several parties to communicate with each other over the telephone. The party that sets up the conference call, calls each party in turn who can then all talk to each other.

Also known as Hotline or baby call. This feature of a telephone blocks the free dialling of telephone numbers. As soon as the handset is picked up and any key is pressed, the telephone automatically dials a pre-defined number.

The acoustic ringing signal (ringing melody) is switched off or the call is rejected.

A feature of telephones that have a microphone and a loudspeaker. It allows a number to be dialled and a conversation to be held without having to pick up the handset. Other people in the room can also listen to the conversation and take part in it. Intercom connection: Wireless connection with a cordless telephone between the handset and the base station that provides the same functions as a small intercom system.

The Integrated Service Digital Network is a nationwide digital network from British Telecom in the UK or from Deutsche Telekom in Germany. It integrates a range of services in a transmission network. Services such as telephone, fax and data communication are at the disposal of the user with their ISDN connection. They can also use these services simultaneously. Thus you can use two telephones at the same time for different telephone calls or be by reachable by telephone even when you are surfing the Internet.

A network structure that is limited to a defined local area, generally a company site with several buildings. Areas of more than 10 km are seldom achieved. The currently available technologies permit a transmission rate of around 1 Gbit/s.

Infrastructure, for carrying an information stream, which interconnects several computers.

A filling used for rechargeable batteries for mobile GSM telephones. NiMh batteries have a longer life and are not as badly affected by the memory effect as traditional nickel-cadmium (NiCd) rechargeable batteries.

With telephones it is generally possible to assign telephone numbers to the digit keys using a function key. The connection is subsequently set up simply by pressing a single key.

With telephones it is generally possible to assign telephone numbers to the digit keys using a function key. The connection is subsequently set up simply by pressing a single key. Private telephone exchange. (see also PBX)

Paging is the generic expression used for paging services such as Eurosignal, Citycall, Scall, Quix, TelMI, Omniport. It originates from the verb to page - to put out a call for someone. With this mobile radio service, messages can be transmitted in one direction only.

The Public Switched Telephone Network (PSTN) is the oldest and largest telecommunications network in existence. PSTN is the telephone network that by default most of the world population is connected to if they have a telephone. In most of the cases a connection to another telephone network, e.g., is done on user request.The PSTN network is sometimes called an analogue network -- in contrast for example to ISDN and GSM, which are digital networks. The reason is that the signals carried over the copper line are in an analogue form, that is they have continuously and smoothly varying amplitude or frequency.

Basically it consists of a number of Copper pairs which connect the telephone sockets in our homes to a so called Local Exchange representing an open at the user site network circuit (this part of the network is called as well Local Loop, other term connected to this part is the Last Mile that represents the Copper pair from the Local Exchange to the users premises); number of Local Exchanges then are connected over a Transport (Trunk) network, which today is not necessarily a PSTN network and could for example be an ATM or an IP network.When the user lifts off the telephone receiver (in the case of a cordless telephone like a DECT telephone this event is replaced by a call from the handset to the base station), the network circuit is closed this notifies the system that the user wants to communicate. The system provides the user with dialling tone back, which is indication that the calling user can now dial the telephone number of the (called) user he wants to communicate with. If the number is already available into the telephone (being for example pre-dialled, or stored in a telephone book), this will be transmitted to the network, otherwise the calling user needs to dial it in. Physically, on the line, the number is provided in one of the two possible ways, namely in a pulse or a Dial Tone Multiple Frequency (DTMF) mode. Pulse is the older, still existing, way of doing this job. The numbers are distinguished by the number of electrical impulses sent over the line. The DTMF mode differentiate the numbers by their melody, which is represented by a pair of tones per each number sent on the line (in addition to the numbers the characters A, B, C, D, * and # have defined melody too). When the Number arrives into the local exchange the network starts a series of circuits connections based on the meaning of the digits into the number, which at the end result in establishing a circuit between the calling user with the called user terminal.

Voice and Data are the two basic services supported over PSTN. They have different requirements from the point of vie of the quality of service that is qualified as acceptable.Different PSTN operators in different countries have chosen to implement different PSTN services which means that not all possible PSTN services could be find in different countries and even within one and the same country depending on the PSTN operators choice. The following list shows just few of the services that you may have on offer from your operator: Calling line identification presentation (CLIP): Also called caller ID, this service allows a called party to see the telephone number of an incoming call on a display connected to the telephone line. There are two commonly accepted ways of transmitting the CLIP information - via DTMF or Face-Shift Key (FSK) signalling; Call forwarding: This service re-routes incoming calls to another number. Call-back (completion of call to a busy subscriber): If the called subscriber is busy, the caller can order the call-back service, which means that he is queued for connection to the busy number and when that subscriber gets free the network will connect and notify the caller. Call waiting: A special signal is generated during a call in progress to indicate that a third party is trying to reach you. In addition to offering you a pure voice service, a telephone can be an extremely efficient tool for a subscriber who wishes to send a message, make a financial transaction, or just send a short message (SMS) to another telephoneDTMF, however, is not capable to provide in all cases all the means needed - for example, if a SMS message is to be sent/received it would require a full set of numbers and letters to be available which DTMF does not provide - instead the already mentioned Phase-Shift Key (FSK) signalling is used.

This type of connector (also known as the Western socket) is used with todays modems for the connection of the (four-wire) telephone cable.

Telephone sets, video telephones, facsimile machines, PCs, main frame computers, etc.

In a Wireless Local Area Network, the network cables used in conventional LANs are replaced by wireless radio connections. This allows wired networks to be extended to wirelessly connected computers. The user hardly notices any difference between the computers connected by Ethernet and those connected by WLAN.