Abstract: A traffic management system manages, distributes, and controls various traveling states of vehicles at a high quality level. A vehicle-mounted unit performs an interconnection process for user authentication when entering a predetermined radio-wave zone. A radio unit disposed on a road sends interconnection process completion information to a center device when the interconnection process for connection to the vehicle is completed. If the vehicle does not connect to the radio unit after elapsed of a predicted time at which the vehicle is expected to travel across the radio unit, then the radio unit sends an overtime to the center device. The interconnection process completion information is received, the center device calculates a predicted time at which the vehicle is expected to pass across a radio unit, and sends the predicted time to the radio unit. When the overtime is received, the center device determines whether a fault has occurred or not.

Abstract: The present invention provides a method for forwarding frames between Ethernet network nodes in which an output queue is provided for storing frames to be forwarded in the same direction, and more than one frame stored in the output queue are combined into a single frame, and the combined frame is then transmitted to the output port corresponding to that direction. With this configuration, packets encapsulated into a plurality of frames are stored in the output queue during transmission of the previous frames in the same direction or during their inter-frame gaps, and then combined into one packet, the combined packet being encapsulated into one frame to be transmitted. Accordingly, the amount of data that can be transmitted during a certain time period is increased by the amount equivalent to the reduced number of inter-frame gaps compared to when packets encapsulated into a plurality of frames are individually transmitted, thereby achieving more efficient frame forwarding.

Abstract: A data sending system which prevents a parity error occurrence in a data receiving unit is provided. The data sending system provided is related to data sending systems and, particularly, to a data sending system where plurality of data sending units share a path for data transmission. The data sending system provided comprises a network consisting of a data path and control path, a control unit for instructing data sending through said control path, one or plural data sending units for sending, according to an instruction from said control path, data to a specific one of plural logical paths of said data path, and a data receiving unit permanently connected to the one of plural logical paths of said data path. Said control unit has a determining section which determines a time span, during which no sending data exists in a logical path connected to said data receiving unit, and also instructs a specific unit of said data sending units to send dummy data during the time span.