ITU-T Recommendation for specifying the UNI signaling protocol in N-ISDN.
A method for encoding digital data in an analog signal in which each combination of phase and amplitude represents one of sixteen four bit patterns. This is required for fax transmission at 9600 bits per second.
Quadrature Shift Keying modulation method, which, of practical modulation techniques, has the best bandwidth efficiency per information symbol (baud). It is used in most modems.
A modulation technique that encodes a signal by modulating its amplitude to represent data. The data can be represented by changing the signal to any of 16 or 32 different states.
Voir MAQ.
Five broad categories outlined by the ATM Forum's UNI 3.0;implementation details and precise characteristics are to be determined in the future. Refers to the set of ATM performance parameters that characterize the traffic over a given virtual connection(VC). These parameters include the CLR, CER, CMR, CDV, CTD and the average cell transfer delay.
5 catégories de services ont été distinguées par l'ATM Forum UNI dans sa version 3.0 qui detaille et précise les caractéristiques qui devront être déterminées dans le futur. La qualité de service fait référence à un certain nombre de paramètres de performance qui caractèrisent le trafic à travers une connexion virtuelle donnée( VC). Ces paramètres inclus CLR,CER, CMR, CDV,CTD et le retard moyen des cellules.
Five service classes are defined by the ATM Forum in terms of the QoS parameters.
Class 0 is effectively a "best effort" attempt at delivery; it is intended for applications that do not require a particular class of service. This class of service is sometime called Class 5.
Class 1 specifies the parameters for circuit emulation, CBR (uncompressed) video and for VPN. It specifies performance requirements and indicates that ATM's quality of service should be comparable with the service offered by standard digital connections.AAL1 supports this kind of connection-oriented service.
Class 2 specifies the parameters for VBR audio and video. AAL2 supports this delay-dependent,connection-oriented class. It specifies necessary service levels for packetized video and voice.
Class 3 specifies the parameters for connection-oriented data transfer protocols, particularly frame relay. AAL3/4 and mostly AAL5 supports this delay-independent class of service.
Norme de signalisation développée à l'ECMA et basée sur la signalisation CCITT normalisée (Q.931). Elle vise à permettre des échanges cohérents entre les systèmes de signalisation publics et les systèmes de signalisation privés.