A communication device for acquiring a traffic information of an acquisition object, wherein the communication device is mounted on an automotive vehicle, the device comprising:
- a communicating element for communicating with at least one of a plurality of cooperative communication devices, which is disposed around the communication device;
- a request message transmitting element for transmitting a request message to at least one of a plurality of cooperative communication devices through the communicating element, wherein the request message includes a request vehicle identification information, a target zone information and an information for specifying the traffic information of the acquisition object, wherein the request vehicle identification information defines an identification information of a request vehicle, which requests the traffic information of the acquisition object, and wherein the target zone information defines a target zone, in which a target communication device as the acquisition object is disposed;
- a request message receiving element for receiving the request message, which is transmitted from at least one of a plurality of cooperative communication devices;
- a request message transferring element for transferring the request message to at least one of a plurality of cooperative communication devices, the request message received by the request message receiving element;
- a response message transmitting element for transmitting a response message to at least one of a plurality of cooperative communication devices when the automotive vehicle is disposed in the target zone and when the traffic information of the acquisition object is capable of transmitting and retrieving from the traffic information in the communication device of the automotive vehicle, wherein the response message includes the request vehicle identification information and the traffic information of the acquisition object;
- a response message receiving element for receiving the response message from at least one of a plurality of cooperative communication devices;
- a response message transferring element for transferring the response message to at least one of a plurality of cooperative communication devices when the automotive vehicle is not the request vehicle;
- an outputting element for outputting the traffic information of the acquisition object to an external circuit when the automotive vehicle is the request vehicle;
- a request vehicle zone specifying element for specifying a request vehicle zone, in which the request vehicle is disposed;
- and
- a message transfer zone specifying element for specifying a message transfer zone, which includes the request vehicle zone and the target zone so that the message transfer zone links the request vehicle zone and the target zone, wherein
- the request message transmitting element transmits the request message together with an information of the message transfer zone,
- the response message transmitting element transmits the response message together with the information of the message transfer zone,
- the request message transferring element determines whether the request message is transferred or not on the basis of the information of the message transfer zone and a position of the automotive vehicle, and
- the response message transferring element determines whether the response message is transferred or not on the basis of the information of the message transfer zone and the position of the automotive vehicle.