高速移动场景下的平稳宽带车载视频点播系统设计

Design of stable broadband in-vehicle video-on-demand system in high-speed mobile scenarios

摘要:

针对列车乘客在接入路侧蜂窝移动网络时因多普勒效应而引起的带宽稳定性差的问题，设计了一种高速移动场景下的平稳宽带车载视频点播系统，用户可在手机客户端通过WiFi连接固定于车厢内的车载服务器以下载或上传本地视频资源；此设计中，通信两端均在车厢内部，处于相对静止状态，因此可有效避免多普勒效应；同时，使用了定向增益天线来增强信号在车厢窄长矩形区域的有效覆盖；最终，实验数据表明：该系统在30*10 m的室内场景下，移动终端访问的实时传输带宽基本在35 Mbps到56 Mbps之间且波动较小，可实现稳定流畅的视频服务。

Abstract:

When train passengers are connected to the mobile network, the Doppler effect will make the bandwidth stability worse. To resolve this problem, A stable broadband in-vehicle video-on-demand system in high-speed mobile scenarios is designed. Users can download or upload local video resources by connecting to the on-board server fixed in the car through WiFi on the mobile client. Due to the relatively static on both ends of the communication, the Doppler effect can be alleviated effectively. Furthermore, the directional antenna is employed to meet the strip rectangular area of carriage. The experimental data shows that: in an indoor area within 30*10 meters, the real-time transmission bandwidth accessed by the mobile terminal is basically between 35Mbps and 56Mbps, and transmission bandwidth fluctuation is small, which can achieve stable and smooth video service.