【摘要】 VBR视频传输的突发性是影响 ATM网络服务质量的关键因素 ,文中通过模糊控制方法对视频传输流量的阈值进行监控 ,实现了接入的平滑并可动态调整传输速度 .文中以传输流量及突发级作为评价指标进行分析 ,结果表明 VBR视频传输自适应平滑策略的实效性 .更多还原

【Abstract】 ATM is the technology to support a wide variety of multimedia services with diverse statistical characteristics and quality of service (QoS) requirements at cell and call levels. Among the various kinds of services, video service is becoming an important component of multimedia communications. Because of VBR MPEG code characteristics of I frames, B frames and P frames, VBR video data is a bursty source. The burstiness of VBR video transmission is one key factor to effect quality of service in ATM network, such as cell loss ratio, delay and jitter. In this paper, we focused on dealing with the VBR MPEG video bursty traffic to provide a more suitable QoS. the article obtained the constraint condition of VBR video transmission rate based on the predictions of VBR video sequences and buffer sizes. An adaptive video traffic smoothing strategy is proposed, which monitor the constraint condition of VBR video transmission rate and smooth maximally video data flow over ATM network using fuzzy control system. To retain efficient network resource usage, simultaneity we designed share memory in place of individual buffer as the channel buffer in ATM multiplexer. The adaptive smoothing strategy on VBR video transmission in ATM network is demonstrated in terms of transmission rate and burst level. The result shows that the strategy is effective.更多还原