ltant John Causebrook graduated in physics from the University of London in 1970 and obtained his doctorate for research into radio wave propagation in 1974. He worked for the BBC research department on broadcast coverage and frequency planning and later for the IBA, directing the work of several teams of propagation and broadcast-planning engineers. Dr. Causebrook participated in engineering the mobile phone network at Vodafone, the main product of which was a computer system for showing the coverage of networks that is used in the broadcasting-planning process. He also worked on the parameters for base stations and radio health of the mobile phone industry, was chairman of an international group that studied the subject, and lectured to University M.Sc. students in this area. Dr. Causebrook has published many technical papers and books and has presented several papers at inter- national conferences. In 1978 he received the Oliver Lodge Premium Award from the IEE for his paper on propagation. Ken Guild, M.Eng, Ph.D. University of Essex Ken Guild is currently a senior lecturer within the Department of Computing and Electronic Systems Engineering at the University of Essex, U.K. He received an M.Eng. degree in elec- tronic and electrical engineering from the University of Surrey in 1993. Between 1993 and 1997, he was with Alcatel Submarine Networks, and worked on a variety of projects related to advanced optical transport networks and systems. In 1997, Ken joined the University of Contributors Essex as a research assistant and concurrently undertook obtaining a Ph.D. degree in optical packet-switched networks. After cofounding a startup that developed optical cross-connects in 2000, he moved to Marconi (now Ericsson) in Germany and was responsible for the modeling and design of next-generation networks. His current research interests include dynamic multilayer optical networks, bandwidth provisioning mechanisms for fixed/mobile services, and future optical packet-switched networks. He has published more than 50 pa