Web Applications for Sharing Teacher PC Screen to Student PCs via WebRTC

We develop a pair of web applications written in JavaScript that allow the teacher’s PC screen to be viewed on each student’s PC via WebRTC communication. Assuming that the teacher has taken the trouble to install the Node.js runtime environment on his or her PC, we write the signaling server in JavaScript using Node.js to run on the teacher’s PC and have it manage the WebRTC connections so that all network traffic stays within the classroom. The web applications loaded on the browsers on the teacher’s PC and the student PCs connect to the signaling server via WebSocket. The signaling server then organizes the student applications into a binary tree. The first student’s web application to connect to the server becomes the root of the binary tree and receives the screen images directly from the teacher’s web application, while the second and subsequent student’s web applications are added to the tree as child nodes of the already connected student’s web applications. Each student’s web application forwards the screen images to the child nodes to implement multi-hop transmission.