VBR视频业务的混沌特性与混沌信源建模

Source modeling for VBR video traffic based on chaos

信源建模是研究不同业务量条件下网络特性的基本课题之一 ,近年来视频业务的信源建模已成为宽带综合业务数据网 (B- ISDN)的研究重点。该文从混沌的角度出发 ,对实测的 MPEG及会议电视数据进行混沌特性分析 ,并由此提出了一种基于混沌映射的建模方法。从仿真结果可以看到 ,混沌映射模型既能刻划出可变比特速率 (VBR)视频业务所特有的长时相关性 (L RD)又能相当精确地把握了 ATM节点的丢失 -延迟特性 。

Source modeling is a fundamental issue in studying the performance of networks for different traffic conditions. In the recent years emphasis has been put on modelling the output of video sources involved in Broadband Integrated Services Digital Network (B ISDN). After analysing the chaotic characteristics of several actual MPEG and video meeting sequences, a new modelling method was proposed based on the use of chaotic maps to generate simulated sequence. The performances of ATM nodes carrying video traffic were observed using both real and simulated input sources. The results show that the proposed model is accurate enough to capture not only the long range dependence (LRD) feature of varied bits rate (VBR) traffic but also the loss delay characteristics of the node so it can be used as a simple and practical model.