Driving assistance device, driving assistance method, and driving assistance system

The invention provides a driving support device, a driving support method and a driving support system, which can be used for a moving body without a sensor and can support the driving of the moving body while suppressing the processing load on the side of the moving body. A driving assistance device includes: a storage unit that stores at least a three-dimensional model representing a movement area; an input unit capable of receiving, from a sensor group provided in the moving region, first height information indicating a first height, which is the height of the moving body, and second height information indicating a second height, which is the height of an object satisfying a predetermined distance reference with respect to the moving body; an extraction unit that extracts a first plan view from the three-dimensional model on the basis of the first height information and extracts a second plan view from the three-dimensional model on the basis of the second height information; a generation unit that combine