Renesas Electronics Corporation

Hiroshi Chano

Suguru Fujita

A semiconductor device includes a transmission control unit which performs transmission processing, an area determination unit which determines whether an own vehicle is located in an intersection area, and an operation mode determination unit which determines either a control mode or a terminal mode as an operation mode of a radio terminal device based on an identification information for identifying a source of a received communication frame, and a determination result by the area determination unit. When the operation mode is determined to be the control mode, the transmission control unit outputs, as transmission data, a communication frame including generated control information. When the operation mode is determined to be the terminal mode, the transmission control unit outputs transmission data in synchronization with the received communication frame.

Semiconductor device, radio terminal device, and communication method of radio terminal device

A semiconductor device includes a communication unit which receives a frame at a first transmission period, demodulates control information from a received frame, modulates transmission data, and broadcasts a modulated transmission data at a second transmission period as a radio frequency packet signal, a period determination unit which determines the second transmission period based on vehicle information, and a transmission and reception control unit which generates a transmission timing trigger signal for determining a transmission timing of the transmission data based on the control information and the second transmission period, and outputs the transmission data to the communication unit in synchronization with the transmission timing trigger signal. The second transmission period is equal to or longer than the first transmission period.

Semiconductor device, radio terminal device, radio communication system and communication method of radio terminal device

A radio communication device includes an application execution unit which generates first transmission data including first application identification information, a communication unit which receives a message including first reception data including the first application identification information, and an occupancy rate determination unit including a transmission ID number counter which counts the number of first application identification information included in the first transmission data and which outputs a count result as a first transmission ID count value, a reception ID number counter which counts the number of first application identification information included in the first reception data and which outputs a count result as a first reception ID count value, and a comparison unit which compares the first transmission ID count value with the first reception ID count value to determine the number of transmission data and the number of reception data have a predetermined ratio.

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Tokyo, Japan

Hiroshi Chano