Abstract
This chapter describes the concept of system architecture and Open Systems Interconnection (OSI) for communications, and explains their relevance to RTI (Road Transport Informatics), using the RTI Enterprise model. The communication requirements of various applications are reviewed. These include: a) emergency calls; b) automatic vehicle location and tracking; c) traffic and travel information; d) automatic debiting; e) accident avoidance; and f) platooning. Suitable bearer networks are discussed briefly. These include: a) beacons; b) downlink-only networks; and c) mobile data systems. Some initiatives to standardize communication system interfaces are also presented.