Wireless Real-Time Video Transmission System Based On Multi-link Aggregation

With the development of computer hardware and software technology and the improvement of video technology, online video has emerged as one of the most important networking applications and one of the best channels of information dissemination, affecting people's lives. In recent years, wireless communication technology has grown rapidly, however sending or receiving video services through the wired network hasn't been able to meet the demand of providing video services more flexibly and conveniently, so that video services from wireless channel has undoubtedly become the most urgent requirement. However, currently the low-bandwidth of the wireless communications environment is seriously restricting the development of wireless real-time video transmission. Although those domestic 3G Network Providers have finished the building of 3G networks nearly, the bandwidth of 3G networks is not enough to meet the needs of High-Definition video and multi-channel video scene. So the bandwidth of those existing wireless transmission channels is still not enough to meet the needs of high bit-rate real-time video transmission.To solve this problem, the paper designs and implements wireless real-time video transmission system based on multi-link aggregation. The system uses raw socket programming to implement the multi-link aggregation, and uses the congestion control mechanism TFRC to control the bandwidth of each link, effectively increasing the data transfer rate and improving the stability. Meanwhile, in order to meet the need of real-time, the system uses early-drop and key-frame first optimization strategies to ensure the real-time of the video transmission and uses rate adaptive strategy to dynamically adapt the instability of the wireless network for providing smooth playback of video.In order to verify the proposed wireless real-time video transmission system, the paper evaluates it in the real world and simulation environments. Evaluation results shows that our system not only fully utilizes all the available link bandwidth, greatly enhancing data transmission rate, but also flexibly coordinates all the links to achieve global load balancing, significantly improving the stability of data transmission. It's shown that our system is very good in availability, stability and real-time, and can have good video quality of video transmission.