ARM-based Wireless Real-time Road Video Transmission

In recent years, with the development of the wireless communications and the next generation networks, wireless real-time video transmission is used more widely, this topic is a sub-project from "Information Highway Maintenance System in Henan Province" Project, which aims is that by wireless real-time video transmission system, the video images of damaged road surface can be real-time transmission to the provincial road maintenance center. However, due to the narrow bandwidth of wireless channel and wireless network with instability, wireless real-time video transmission is fluctuated greatly and is prone to packet loss and delay jitter and so on. How to adapt to the changes in the wireless network bandwidth and provide the best service will become to the current research focus.This thesis focuses on the key technologies of the real-time video transmission system. First this thesis discusses real-time video transmission protocol RTP / RTCP. In order to ensure real-time video transmission, the data channel uses RTP / UDP protocol and the control channel uses RTCP / TCP protocol. However, RTP does not provide a reliable delivery mechanism, flow control and congestion control. So this thesis presents the new RTCP adaptive feedback congestion control algorithm. The experiments show that the new algorithm can control congestion better so that it can ensure the reliability and stability of video transmission. Then this thesis analyzes ARM-based wireless real-time road video transmission system which is divided into seven modules: GPS information collection, video capture, video encoding, data transmission, data receiving, video decoding and displaying, GPS information storage. Implementation of each module is analyzed detailedly. GPS information acquisition and video capture are synchronized. The video frames and the GPS information are associated in order to that the video can be associated with the google map through GPS information. So we can play the videos on the google map. Finally in the 3G wireless environment, this system runs better and the receiver can display the videos fluently.This ARM-based wireless real-time wireless video transmission system has been run successfully under the 3G environment.It will have some practical value.