Communication control device
A vehicular communication control device includes: a communication packet generator generating a vehicle information packet indicating a vehicle traveling state; a transmission processor transmitting the vehicle information packet to a peripheral vehicle in a predetermined transmission cycle; a road information acquisition unit acquiring forward road information including a road connection point position at which a host vehicle traveling road is connected to another road; and a positional relationship determination unit determining, based on the forward road information, whether a remaining distance to the road connection point is equal to or smaller than a predetermined cycle change distance. The transmission processor: sets a predetermined first cycle as the transmission cycle when the remaining distance is larger than the predetermined cycle change distance; and sets a second cycle shorter than the first cycle as the transmission cycle when the remaining distance is equal to or smaller than the cycle change distance.
1. A communication control device for a vehicle, controlling a wireless communication with a peripheral vehicle disposed around the vehicle via a wide area communication network, the communication control device comprising:
a computer having a processor and configured to
generate a vehicle information packet, which is a communication packet indicating a traveling state of the vehicle, based on a detection result of a sensor mounted on the vehicle;
control transmitting the vehicle information packet to the peripheral vehicle in a predetermined transmission cycle;
acquire forward road information including a position of a road connection point that connects a host vehicle traveling road, on which the vehicle travels, to another road; and
determine, based on the forward road information, whether a remaining distance to the road connection point, to which the vehicle travels, is equal to or smaller than a predetermined cycle change distance, wherein:
the computer is further configured to
set a predetermined first cycle as the transmission cycle in response to determining that the remaining distance to the road connection point is larger than the predetermined cycle change distance;
set a second cycle shorter than the first cycle as the transmission cycle in response to determining that the remaining distance to the road connection point is equal to or smaller than the predetermined cycle change distance;
generate a second cycle request packet, which requests the peripheral vehicle to set the second cycle as the transmission period, in response to a second cycle condition for setting the transmission cycle to the second cycle being satisfied; and
control transmitting the second cycle request packet.
2. The communication control device according to claim 1 , wherein:
the computer is further configured to determine a value to be set as the cycle change distance based on at least one of a traveling speed of the vehicle and a type of the road connection point.
3. The communication control device according to claim 1 , wherein:
the computer is further configured to
determine whether another vehicle corresponding to the peripheral vehicle is disposed within a predetermined area from the vehicle, based on whether the vehicle information packet transmitted from the peripheral vehicle is received; and
set the first cycle as the transmission cycle in response to determining that the peripheral vehicle is not disposed within the predetermined area even when determining that the remaining distance to the road connection point is equal to or smaller than the predetermined cycle change distance.
4. The communication control device according to claim 1 , wherein:
in response to switching the transmission cycle from the second cycle to the first cycle in association with passing the road connection point, the computer is further configured to control the transmission cycle closer to the first cycle in a stepwise fashion according to a distance passed from the road connection point or an elapsed time from a passing time point.
5. The communication control device according to claim 1 , wherein:
in response to receiving the second cycle request packet, the computer is further configured to set the transmission cycle to the second cycle.
6. The communication control device according to claim 5 , wherein:
the computer is further configured to transmit a return permission packet, which is a communication packet that permits the transmission cycle to return to the first cycle, in response to the second cycle condition no longer being satisfied after transmitting the second cycle request packet.
7. The communication control device according to claim 6 , wherein:
the computer is further configured to set the transmission cycle to the first cycle in response to receiving the return permission packet from all of vehicles corresponding to transmission sources of the second cycle request packet in a case where the transmission cycle is set to the second cycle based on reception of the second cycle request packet.