This conference in Enschede, The Netherlands, is the sixth in a series of international conferences and workshops under the title Protocols for Multimedia Systems, abbreviated as PROMS. The first PROMS workshop took place in June 1994 in Berlin, Germany, followed by workshops in Salzburg, Austria (October 1995) and Madrid, Spain (October 1996). In 1997, PROMS formed a temporary alliance with Multimedia Networking, a conference previously held in Aizu, Japan, in 1995. This led to the international conference on Protocols for Multimedia Systems - Multimedia Networking, PROMS MmNet, that took place in Santiago, Chile (November 1997). Since then PROMS has been announced as an international conference, although informal contacts and interactive sessions - as in a workshop - were retained as a desirable feature of PROMS. After a gap of three years, PROMS was organized in Cracow, Poland (October 2000), for the fifth time. We consider it a challenge to make this sixth edition of PROMS as successful as the previous events. The goal of the PROMS series of conferences and workshops is to contribute to scientific, strategic, and practical cooperation between research institutes and industrial companies in the area of multimedia protocols. This is also the goal of PROMS 2001. The basic theme of this conference continues to be multimedia protocols, both at the network and application level, although the increasing interest in wireless, mobility, and quality of service as interrelated topics with relevance to multimedia are reflected in the current program.