ISABEL: A CSCW Application for the Distribution of Events

Introduction Many activities which in the past have required physical presence and direct interaction among participants can be performed in a distributed fashion with the help of advanced information technologies such as, CSCW [1,2] (Computer Supported Cooperative Work), interactive multimedia services and broadband communications. Technologies aiming at supporting the collaboration among individuals or groups are identified under the term groupware technologies. Asynchronous interactions which do not require physical presence of interacting persons have matured during the last years. Very successful examples of asynchronous groupware exist. LOTUS Notes [3] is considered probably the most successful commercial product in this area. The Internet and many of its application can be considered as groupware technologies to some extend. Technology can support today also synchronous interaction where real time contact among individuals is required. We mean by synchronous interaction the exchange of verbal, visual, ... messages or information, like the exchanges of information carried out typicaly in meetings, conversations or other activities where several participants collaborate in physical presence. Remote synchronous interaction is not new, the plain old telephone is a very good example of an old technology supporting a simple but very effective form of synchronous interaction. POTS is today by far the most demanded synchronous service. This service has evolved into N to N audioconference or videoconference facilities. Computers in general and the Internet have also had primitive types of character oriented synchronous interactive services for a long time, like TALK, IRC, ... Today low quality voice and video over the Internet is also common practice with applications like, CU-SeeMe, IVS, VAT, ... Audiovisual broadcasting is also a highly demanded type of remote synchronous interaction which has been done since many years. Although broadcasting has really no interaction because the flow of information is unidirectional, it is nevertheless being addressed in the experiments performed for creating new synchronous services. One of the most popular services on the multicast backbone of the Internet, also known as the MBONE, is the conference broadcasting for which a Session Directory (SD) exists where the list of broadcast conferences is displayed in real time. Sophisticated forms of remote synchronous interaction requiring good quality telepresence demand more bandwidth and more reliable communications to achieve a proper interaction. Therefore for setting up large sacle experiments like the RACE/ACTS Summer Schools [2,5,6,9] a complex collaboration among a large number of organizations has been needed. In addition, the availability of large …