The goal of this effort is to devise and analyze an integrated Physical/ Link-Access Layer Model of packet Radio Architectures, with application to the PATH/IVHS (Intelligent Vehicle Highway Systems) communication sub- system design between vehicles and infrastructure, as well as between vehicles on the move. The present report contributes to a generic conceptual model for system evaluation which can be used for quantification of the interaction between network layers. The research tasks that have been performed for achieving the project objectives include collection of data requirements for Advanced Traffic Management and Information Systems (ATMIS), Advanced Vehicle Control Systems (AVCS) as well as for an integrated ATMIS/AVCS system, definition of communication system requirements (user's integrated data traffic, attributes of the integrated system), analysis and performance evaluation of multiple access schemes for vehicle-to-roadway and vehicle-to-vehicle communications, identification of multiple access protocols that can accommodate the communication needs of the integrated ATMIS/AVCS data traffic, and a complete performance analysis of an asynchronous multi-cell Direct-Sequence Code Division Multiple-Access (DS/CDMA) microcellular system for both uplink (vehicle to base station) and downlink (base station to vehicle) communications.

The objective of this study is to address the communication system design issues of Intelligent Vehicle Highway Systems (IVHS). The focus of Phase I of this research is the design for California Advanced Driver Information Systems (CADIS). The emphasis is on the architecture and topology aspects of the physical link and access layers connecting the moving layers with the fixed infrastructure. The work is divided into the following categories: Automatic Vehicle Identification (AVI), IVHS communications survey and functional requirements, modeling of IVHS fading channels, multiple-access performance analysis, simulation for IVHS communications, system layout and architectural tradeoffs, throughput/ delay analysis, and FM Subcarrier and the IVHS environment.