ITU-T有关下一代网络的研究

作为一个全新的概念,下一代网络(NGN)常常被人们用来描绘未来电信网的概貌。但是,不同的运营商、制造商或业务提供商对NGN有着不同的理解而且差别甚大,故希望在NGN的定义上能够统一,并能最终实现标准化。这就是国际电信联盟标准委员会(ITU-T)决定启动NGN项目的原因。该项工作由其下属的第13研究组(SG-13)负责。该项目的研究目标将与原有     

Activities on next-generation networks under Global InformationInfrastructure in ITU-T

Next-generation networks (NGN) is a new concept commonly used by network designers to depict their vision of future telecommunications networks. However, various views on NGN have been expressed so far by operators, manufacturers, and service providers, and the general wish is now to come to a common understanding on NGN and to prepare standards on it. This is the reason why the ITU-T has decided to start the standardization process on NGN under the form of a new ITU-T Project prepared by Study Group 13. This new Project is in line with results from the existing ITU-T Project on Global Information Infrastructure (GII) because NGN is seen as a concrete realization of the GII. The NGN 2004 Project is a coordination structure led by Study Group 13, with the role of organizing studies on NGN in ITU-T. The target for the NGN 2004 Project is to prepare Recommendations in 2004     

The `Prelude' ATD experiment: assessments and future prospects

The Prelude experimental model represents a complete network which can integrate any bit rate from data to moving pictures by an asynchronous time-division (ATD) technique. To get reliable and full assessment of ATD, the model is made up of a switch, a concentrator, two home networks, and terminals. The project started in 1982 and was completed in the middle of 1987. The success of the experiment proves the feasibility of ATD, which is now agreed on as a possible solution for future ISDN (integrated-services digital network) use. The authors address the results derived from the experiment and analyze the trends that can be expected for the future. First, an outline of Prelude is given to describe the state of the arc reached within the experiment. Each element of the system is described with special emphasis on the switching matrix, as its optimized and efficient implementation could lead to short-term industrial developments. Then a thorough assessment of the whole system is given from which future evolutions are most likely to be derived. Possible ATD fields of application are given