New Services such as for Internet data and multimedia applications, have caused a fast growing demand for broadband communications. The fundamental technologies for the integration of these services have been developed in the last decade: optical communications, photonic switching, high speed local area networks, Asynchronous Transfer Mode (ATM), ISDN and B-ISDN, Internet packet networks and mobile communications. The development was possible through the dynamic progress in communication and computer technologies and through worldwide standardization activities within ITU-T, the ATM Forum, the IETF, IEEE, ANSI, ETSI and other bodies. These developments have been supported by research and field trial programmes. Past developments, such as about LAN, Internet or ISDN networking technologies, have shown that it needs a time span of 10 years for a new technology from its research stage to its full application. Broadband Communications is just at its onset for full deployment. It will have a dramatic effect not only on the networking situation but on the whole development of information technology throughout our social and economic life, which is expressed by the conference theme ,The Future of Telecommunications". The Broadband Communications conference series of IFIP WG 6. 2 addresses the fundamental technical and theoretical problems related with these technologies. BC '98 is the fourth meeting in a series on conferences being held in Stuttgart, Germany. The previous confernces were held in Estoril, Portugal, in 1992, in Paris, France, in 1994, and in Montreal, Canada, in 1996.