Development of a Multipurpose Audio Transmission System on the Internet

It is becoming easy to use audio communications on broadband networks. There have been many variations of audio communications. In our study, we classify conditions of audio communications required in various situations and design a multipurpose audio transmission system called as “MRAT (Multipurpose RAT)”. We enhance RAT (Robust Audio Tool) that is one of audio communication tools, and add two new options. One is to keep shorter delays between end-nodes. Another is an error recovery using a Forward Error Correction with Reed- Solomon code, to recover packet losses. By using these options, MRAT has three modes; a Chorus mode, a Conversation mode, and a Broadcast mode. Therefore, MRAT can correspond to various scenes. We show some evaluations of MRAT like measurements of end-to-end delays and effects of an error recovery. We also show practicality of MRAT by practical experiments such as distance chorus at multi-points and distance lectures.