Real-time interactivity on the SuperJANET network

Abstract

The experience of using the SuperJANET (ATM) asynchronous transfer mode video network for teaching surgery to undergraduates is reported, and the requirements for teaching and conferencing are contrasted. The network is used to Link six UK University Medical Schools to deliver an 18-session course three times per year. Each session is designed to be a multimedia presentation encouraging students to interact with each other and with the lecturer.The paper is divided into three sections; the first describing the nature of the network, the second the discussing technical and pedagogical matters concerning interaction on the network, and the third drawing attention to the need to give special attention to audiovisual matters if the best quality of video and audio is to be achieved on the network. The signals originate in the teaching space in analogue format and on reaching the CODEC are digitised and passed over the distance network using ATM technology. This requires the collaboration of both the AV personnel with their expertise in analogue video, and the network support personnel to handle the digital signal transmission.The problems discussed include the handling of echo, which is induced as a result of the compression and decompression of the video signal, and the control of network switching of incoming video signals in the interaction between students and lecturers. Attention is also drawn to the differences between videoconferencing and video teaching. An example is described of how a site which is not part of the SuperJANET ATM video network is included in the collaborative teaching using a different technology. Finally there is a need to integrate the real-time teaching with self-learning, so network resources have been implemented to support both Live teaching and CAL (computer aided learning).Changes have been made in the way teaching is carried out as a result of the feedback from both students and teachers. The solutions and changes are usually the results of compromise between what the teachers would prefer and the functionality of the network. The experience of television production has had a major impact on the way interactivity has been established in the network teaching environment.