Abstract: The present application: receives positioning data from each of a plurality of positioning terminals that have received positioning signals transmitted from a plurality of satellites; uses the received positioning data to detect, for each satellite, the difference between the positioning signal reception quality at a first positioning terminal and the positioning signal reception quality at at least one second positioning terminal; and uses the difference for each satellite to determine a satellite to be used for positioning computation for the first positioning terminal.

Abstract: A pedestrian terminal device receives pedestrian information transmitted from another pedestrian terminal device which is present in the vicinity of the pedestrian terminal device. A location of the pedestrian terminal device is acquired, and it is determined whether or not a pedestrian who carries the pedestrian terminal device is located inside a pedestrian group based on the location of the pedestrian terminal device and a location of the other pedestrian terminal device included in the pedestrian information. When the pedestrian is located inside the pedestrian group, pedestrian-vehicle communication is stopped.

Abstract: In order to enable a driver in driving a vehicle to quickly and assuredly recognize a pedestrian having a collision risk with the vehicle even when it is difficult for the driver to recognize the pedestrian by eyes, such as during night time, an in-vehicle terminal device is configured to: determine a collision risk based on pedestrian position information and vehicle position information; generate turn-on instruction information which, when the pedestrian is determined to have the collision risk with the vehicle, causes an indicator light carried by the pedestrian to be turned on in a prescribed light color; and transmit the turn-on instruction information to a pedestrian terminal device via pedestrian-vehicle communication, and wherein the pedestrian terminal device is configured to: receive the turn-on instruction information transmitted from the in-vehicle terminal device; and turn on the indicator light based on the turn-on instruction information.

Abstract: In order to enable a driver in driving a vehicle to quickly and assuredly recognize a pedestrian having a collision risk with the vehicle even when it is difficult for the driver to recognize the pedestrian by eyes, such as during night time, an in-vehicle terminal device is configured to: determine a collision risk based on pedestrian position information and vehicle position information; generate turn-on instruction information which, when the pedestrian is determined to have the collision risk with the vehicle, causes an indicator light carried by the pedestrian to be turned on in a prescribed light color; and transmit the turn-on instruction information to a pedestrian terminal device via pedestrian-vehicle communication, and wherein the pedestrian terminal device is configured to: receive the turn-on instruction information transmitted from the in-vehicle terminal device; and turn on the indicator light based on the turn-on instruction information.

Abstract: Pedestrian terminal device that can save power consumption. The pedestrian terminal device carried by a pedestrian is provided with an operation mode selector for selecting one of a principal terminal operation mode wherein a pedestrian-vehicle communication with an in-vehicle terminal device is performed representing other pedestrian terminal devices, and an in-group terminal operation mode wherein a short-range wireless communication of a shorter range and a smaller power output than the pedestrian-vehicle communication is performed with another pedestrian terminal device operating in the principal terminal operation mode.

Abstract: Even in a crowded situation in which multiple pedestrians and vehicles gather, it possible to sufficiently suppress pedestrian-vehicle communication between a pedestrian terminal device and a vehicle-mounted terminal device, and to reduce communication congestion due to an increase in traffic in pedestrian-vehicle communication.

Abstract: Pedestrian terminal device that can save power consumption. The pedestrian terminal device carried by a pedestrian is provided with an operation mode selector for selecting one of a principal terminal operation mode wherein a pedestrian-vehicle communication with an in-vehicle terminal device is performed representing other pedestrian terminal devices, and an in-group terminal operation mode wherein a short-range wireless communication of a shorter range and a smaller power output than the pedestrian-vehicle communication is performed with another pedestrian terminal device operating in the principal terminal operation mode.