This award will support Professor Mario Gerla of the University of California at Los Angeles in a research collaboration with Professor Luigi Fratta of the Politechnical University, Milan, Italy. The proposers intend to focus on the design of high speed networks. The advances in fiber optics, signal processing and switching technologies, the proliferation of microcomputers and workstations and the increasing sophistica- tion of the end user offer new opportunities for the introduction of enhanced communications services to business and residences. The following main directions of research are proposed: design and evaluation of Metropolitan Area Network (MAN) architectures; performance evaluation and topology configuration of Broadband ISDNs; interconnection of LANs, MANs and B-ISDNs. Novel metropolitan network architectures based on tree topologies and wavelength division multiplexing will be investigated, with the goal of achieving much higher speeds (in the Gigabit range) than available from existing MAN products. Network control and management techniques for high speed, wide area networks will be developed to guarantee efficiency and to prevent congestion.