ITU F.720:1992
ITU F.720:1992 Videotelephony Services - General
Table of Contents
1Introduction2Definition
3Description
3.1Generaldescription
3.2Descriptionofvariousvideo-telephonyservices
3.3Applicationsrelatedtovideo-telephony
3.4Supplementaryservicesandenhancements
3.5Specificterminology
4Procedures
4.1General
4.2Provision/withdrawal
4.3Normalprocedures
4.4Exceptionalprocedures
5Networkaspects
6Terminalaspect
6.1Generalsystemsrequirements
6.2Video-telephoneterminalequipment
7QualityofService
7.1Picturequality
7.2Audioquality
7.3Synchronizationofspeechandlipmovement
(lipsynchronization)
7.4Overalldelay
7.5Sensitivitytotransmissionerrors
8Interworkingandintercommunicationrequirementsworks
8.1Intercommunication/interworkingwithtelephony
services
8.2Intercommunicationbetweenvideo-telephony
servicesondifferentnet
8.3Intercommunicationwithotheraudiovisualservices