Service station for an intelligent transportation system

1. An Intelligent Transportation System (ITS) service station, comprising:

a receiver configured to receive, from one or more sensors, road user information on a set of road users perceived by the sensors, wherein said road user information includes, for each road user in the set, a respective geographical position determined by the sensors;

a controller connected to the receiver and configured to determine, on the basis of said geographical positions, whether a subset of road users in said set meets a predetermined criterion of mutual proximity, the determination of whether the subset of road users in said set meets the predetermined criterion of mutual proximity comprising:

calculating, from said geographical positions, distances between road users in the set, and wherein said criterion comprises that a respective distance of a road user to each of a predetermined number of other road users in the set is smaller than a predetermined distance threshold, and

calculating, from the road user information, heading differences between headings of road users in the set, and wherein said criterion further comprises that the respective heading differences of the road user to each of the predetermined number of other road users in the set are smaller than a predetermined heading threshold; and

a transmitter connected to the controller and configured to transmit, when said subset comprises two or more road users, a service message indicative of said subset.

2. The ITS service station according to claim 1 , wherein said criterion further comprises that a time during which said respective distance has been smaller than the predetermined distance threshold exceeds a predetermined duration.

3. The ITS service station according to claim 1 , wherein said determining further comprises calculating, from the road user information, speed differences between speeds of road users in the set, wherein said criterion further comprises that the respective speed differences of the road user to each of the predetermined number of other road users in the set are smaller than a predetermined speed threshold, and wherein the controller is configured to determine at least one of a heading and a speed of each road user from the geographical positions included in road user information successively received from the one or more sensors by the receiver.

4. The ITS service station according to claim 1 , wherein said predetermined number is one.

5. The ITS service station according to claim 1 , wherein said predetermined number is three.

6. The ITS service station according to claim 1 , wherein said service message comprises a geographical area which includes the geographical positions of the road users in the subset and excludes the geographical positions of other road users of the set.

7. The ITS service station according to claim 1 , wherein the service message is a Collective Perception Message (CPM).

8. The ITS service station according to claim 1 , wherein at least one of said sensors is comprised by the ITS service station and is connected to the receiver.

9. The ITS service station according to claim 1 , wherein the ITS service station is a roadside unit (RSU).

10. An Intelligent Transportation System (ITS) service station, comprising:

a receiver configured to receive, from one or more sensors, road user information on a set of road users perceived by the sensors, wherein said road user information includes, for each road user in the set, a respective geographical position determined by the sensors;

a controller connected to the receiver and configured to determine, on the basis of said geographical positions, whether a subset of road users in said set meets a predetermined criterion of mutual proximity, the determination of whether the subset of road users in said set meets the predetermined criterion of mutual proximity comprising:

calculating, from said geographical positions, distances between road users in the set, and wherein said criterion comprises that a respective distance of a road user to each of a predetermined number of other road users in the set is smaller than a predetermined distance threshold, and

calculating, from the road user information, speed differences between speeds of road users in the set, and wherein said criterion further comprises that the respective speed differences of the road user to each of the predetermined number of other road users in the set are smaller than a predetermined speed threshold; and

a transmitter connected to the controller and configured to transmit, when said subset comprises two or more road users, a service message indicative of said subset.

11. The ITS service station according to claim 10 , wherein said criterion further comprises that a time during which said respective distance has been smaller than the predetermined distance threshold exceeds a predetermined duration.

12. The ITS service station according to claim 10 , wherein said predetermined number is one.

13. The ITS service station according to claim 10 , wherein said predetermined number is three.

14. The ITS service station according to claim 10 , wherein said service message comprises a geographical area which includes the geographical positions of the road users in the subset and excludes the geographical positions of other road users of the set.

15. The ITS service station according to claim 10 , wherein the service message is a Collective Perception Message (CPM).

16. The ITS service station according to claim 10 , wherein at least one of said sensors is comprised by the ITS service station and is connected to the receiver.

17. The ITS service station according to claim 10 , wherein the ITS service station is a roadside unit (RSU).