Design And Implementation Of Network Teaching System Based On WebRTC

With the development of information technology, real economy comprehensively combined with the Internet especially the mobile Internet is becoming an inexorable trend. Traditional physical teaching classroom also need to make development and extension, to keep up with the time tide. Meanwhile, WebRTC(Web Real-Time Communication) has been open-source and written in W3 C working draft. Without any client software or plugin, it can achieve real-time application on the web, and it has features of rich multimedia, cross-platform, low cost of using and development etc.The overall framework of WebRTC was introduced first. It included video codec, audio codec, transmission control modules, signaling mechanisms, we also introduced front-end development technology such as HTML5, Canvas etc. Followed by requirements analysis and system design based on the practical application of network teaching scenarios. Then we have developed an teachers and student-friendly interactive online teaching system. It was based on WebRTC in Node.js environment and Express, with JavaScript as the main language. Many subsystems was designed and implemented, such as real-time and non-real-time online instruction, after-school answering, multiplayer file sharing, and registration login. The one-to-many and many-to-many video and audio communication was implemented by applying MediaStream and RTCPeerConnection interface in WebRTC. The multiplayer interactive real-time whiteboard and text chat was implemented by applying the layered Canvas and WebSocket. Furthermore the system made distinguish of user's privileges according to user type and login status, and users with teacher type had privileges, which is also the important content of system implementation.The system passed the functional tests and performance tests, being able to run well both on the desktop browser and android mobile browser. The result proved we applied WebRTC in Network Teaching System. Finally, the whole work was summarized, and open issues worthy of further study were discussed.