Multimedia group communications: towards new services

Interpersonal communication among a group of users employing different media types is becoming more and more widespread in computing and telecommunications. Group communication places a variety of new requirements onto the underlying communications architecture and although many existing protocols and services do offer some limited support for multicast group communication, these new requirements make it difficult to find efficient and comprehensive solutions. The impact of multimedia group communication on the communication system and the way in which existing systems, international standardization bodies and researchers cope with these challenges is the subject of this paper. First the characteristics and requirements of multimedia group applications are discussed and illustrated by examples of existing group applications. Subsequently a survey of the kind of support available in today's communication system is presented. In addition the ongoing discussion about the standardization of group communication within ISO and ITU and the direction these efforts take is briefly summarized. Further, some selected examples of research projects which deal with different communication and protocol related aspects of multimedia group communication are presented which give an indication of the trends in this area.