The theme of the 18th ITC is "Providing QoS in Heterogeneous Environments", addressing the interworking of old and new networking technologies. The technical programme committee received an overwhelming number of 307 submissions. Each submission has been sent for review to three international experts. In the paper committee meeting in Dresden on April 16-17th attended by 22 TPC members the final selection process has been carried out. Due to the space limitations, only 133 papers could be accepted. Thus, a large number of high quality papers could not be included in the programme.

The ITC submissions reflect the current developments in telecommunications: a paradigm shift to IP related issues, heterogeneous network structures, search for new services, uncertainty toward quality of service, and service level monitoring. A clear trend is crystallised by a close look at the proceedings: In the emerging telecommunication environment, the role of teletraffic is increasingly important but has to be redefined. The topics of 6 plenary and 23 parallel sessions give an idea of the broad range of issues covered by ITC18: Next Generation Networks & MPLS; UMTS; Topology Models & Ad Hoc Networks; Traffic Characterisation & Web Performance; Network Planning & Dimensioning; Routing; Resource Allocation; Measurements; Statistical Multiplexing; Traffic Modelling; Queueing Systems; TCP Modelling; Network Planning Methods; Cellular Networks; TCP Enhancements; Optical Networks; Wireless LAN; Wireless Networks; QoS & Economics; QoS Provisioning; Admission Control & Policing; Voice over IP; Adaptive Queue Manage-ment; Application Servers.