Public data networkA public data network (PDN) is a network established and operated by a telecommunications administration, or a recognized private operating agency, for the specific purpose of providing data transmission services for the public. The first public packet switching network, RETD, was deployed in 1972 in Spain. "Public data network" was the common name given to the collection of X.25 providers, the first of which was DATAPAC in 1976. The International Packet Switched Service became the first commercial and international packet-switched network in 1978.
SyncwordIn computer networks, a syncword, sync character, sync sequence or preamble is used to synchronize a data transmission by indicating the end of header information and the start of data. The syncword is a known sequence of data used to identify the start of a frame, and is also called reference signal or midamble in wireless communications. Prefix codes allow unambiguous identification of synchronization sequences and may serve as self-synchronizing code.
Equalization (communications)In telecommunication, equalization is the reversal of distortion incurred by a signal transmitted through a channel. Equalizers are used to render the frequency response—for instance of a telephone line—flat from end-to-end. When a channel has been equalized the frequency domain attributes of the signal at the input are faithfully reproduced at the output. Telephones, DSL lines and television cables use equalizers to prepare data signals for transmission.
Multidrop busA multidrop bus (MDB) is a computer bus in which all components are connected to the electrical circuit. A process of arbitration determines which device sends information at any point. The other devices listen for the data they are intended to receive. Multidrop buses have the advantage of simplicity and extensibility, but their differing electrical characteristics make them relatively unsuitable for high frequency or high bandwidth applications.
Code de GolayEn théorie des codes, un code de Golay est un code correcteur d'erreurs pouvant être binaire ou tertiaire, nommé en l'honneur de son inventeur, Marcel Golay. Il y a deux types de codes de Golay binaire. Le code binaire étendu de Golay encode 12 bits de données dans un mot de code de 24 bits de long de telle manière que n'importe quelle erreur sur trois bits puisse être corrigée et n'importe quelle erreur sur quatre bits puisse être détectée.
Opérateur de télécommunicationsvignette|Forte concurrence entre opérateurs au Cameroun. Un opérateur de télécommunications est une entité qui met à disposition des services de communication à distance. Cela implique généralement un lien vers au moins un réseau ouvert de communication (exemples : réseau commuté, Internet), mais le réseau peut se suffire à lui-même. Opérateurs mobiles et opérateurs fixes. Opérateurs de services et opérateurs de réseaux. Opérateurs historiques et opérateurs alternatifs.
Asynchronous serial communicationAsynchronous serial communication is a form of serial communication in which the communicating endpoints' interfaces are not continuously synchronized by a common clock signal. Instead of a common synchronization signal, the data stream contains synchronization information in form of start and stop signals, before and after each unit of transmission, respectively. The start signal prepares the receiver for arrival of data and the stop signal resets its state to enable triggering of a new sequence.
