COMMUNICATION CONTROL APPARATUS, COMMUNICATION SYSTEM AND COMMUNICATION CONTROL METHOD

1 . A communication control device comprising:

a predictor that predicts a future traffic amount of a communication link on the basis of prediction information used to predict the traffic amount;

a prediction accuracy calculator that calculates prediction accuracy on the basis of the traffic amount of the communication link in a first period predicted by the predictor and the actual traffic amount of the communication link in the first period;

a threshold value calculator that calculates a threshold value used to determine whether or not congestion will occur on the basis of the prediction accuracy calculated by the prediction accuracy calculator and a transmission ability of the communication link;

a communication terminal number estimator that estimates the number of terminals in communication which is the number of terminals that are performing communication through the communication link;

a transmission duration time calculator that calculates a transmission duration time of the traffic per terminal on the basis of the traffic amount in a second period, which is a period later than the first period, predicted by the predictor, the number of terminals in communication estimated by the communication terminal number estimator, an average rate per terminal, a transmission cycle of traffic, and a transmission interval of the traffic;

a congestion determinator that determines whether or not the congestion will occur on the basis of the traffic amount in the second period predicted by the predictor and the threshold value calculated by the threshold value calculator; and

a path switching determinator that determines whether or not to perform path switching to reduce the traffic amount of the communication link, due to which occurrence of the congestion is predicted, on the basis of a time calculated using the transmission duration time calculated by the transmission duration time calculator in a case where the congestion determinator determines that the congestion will occur, the path switching determinator providing an instruction to perform the path switching to a transfer device configuring a communication network in a case where it is determined to be necessary to perform the path switching.

2 . The communication control device according to claim 1 , further comprising:

a congestion duration time calculator that calculates a congestion duration time which is a duration time of the congestion on the basis of the transmission duration time, the number of terminals in communication, the transmission cycle of the traffic, and the transmission interval of the traffic,

wherein the path switching determinator determines that it is necessary to perform the path switching in a case where a delay time based on the congestion duration time calculated by the congestion duration time calculator is longer than a delay time occurring due to the path switching.

3 . The communication control device according to claim 1 , further comprising:

a congestion time calculator that calculates a congestion time occurring in a period that is later than the second period on the basis of the transmission duration time, the number of terminals in communication, the transmission cycle of the traffic, the transmission interval of the traffic, the prediction accuracy, and the transmission ability of the communication link,

wherein the path switching determinator determines that it is necessary to perform the path switching in a case where a delay time based on the congestion time calculated by the congestion time calculator is longer than a delay time occurring due to the path switching.

4 . The communication control device according to claim 1 , further comprising:

a traffic amount predictor that calculates the future traffic amount per terminal on the basis of the number of terminals in communication and the future traffic amount;

a congestion terminal number calculator that calculates a maximum connection number which is a maximum number of connected terminals within a range in which the congestion does not occur, on the basis of the future traffic amount per terminal predicted by the traffic amount predictor, the prediction accuracy, and the transmission ability of the communication link; and

a congestion duration rate calculator that calculates a congestion duration rate on the basis of the transmission duration time, the number of terminals in communication, and the maximum connection number,

wherein the path switching determinator determines that it is necessary to perform the path switching on the basis of the congestion duration rate calculated by the congestion duration rate calculator and a ratio between a delay time caused due to the path switching and a congestion time in the second period.

5 . The communication control device according to claim 1 , wherein the path switching determinator provides the instruction to perform the path switching before the second period in a case where it is determined to perform the path switching.

6 . The communication control device claim 1 , wherein the communication terminal number estimator estimates the number of terminals in communication on the basis of information related to the terminals in communication included in radio information transmitted from terminals or a communication device that performs communication with the terminals.

7 . A communication system comprising:

a communication device;

a transfer device that configures a communication network and transfers a signal transmitted or received by the communication device via a communication link; and

a communication control device that performs traffic control in the communication network,

wherein the communication control device includes

a predictor that predicts a future traffic amount of a communication link on the basis of prediction information used to predict the traffic amount,

a prediction accuracy calculator that calculates prediction accuracy on the basis of the traffic amount of the communication link in a first period predicted by the predictor and the actual traffic amount of the communication link in the first period;

a threshold value calculator that calculates a threshold value used to determine whether or not congestion will occur on the basis of the prediction accuracy calculated by the prediction accuracy calculator and a transmission ability of the communication link;

a communication terminal number estimator that estimates the number of terminals in communication which is the number of terminals that are performing communication through the communication link;

a transmission duration time calculator that calculates a transmission duration time of the traffic per terminal on the basis of the traffic amount in a second period, which is a period later than the first period, predicted by the predictor, the number of terminals in communication estimated by the communication terminal number estimator, an average rate per terminal, a transmission cycle of traffic, and a transmission interval of the traffic;

a congestion determinator that determines whether or not the congestion will occur on the basis of the traffic amount in the second period predicted by the predictor and the threshold value calculated by the threshold value calculator; and

a path switching determinator that determines whether or not to perform path switching to reduce the traffic amount of the communication link, due to which occurrence of the congestion is predicted, on the basis of a congestion measurement time calculated on the basis of the transmission duration time calculated by the transmission duration time calculator in a case where the congestion determinator determines that the congestion will occur, the path switching determinator providing an instruction to perform the path switching to the transfer device configuring a communication network in a case where it is determined to be necessary to perform the path switching.

8 . A communication control method performed by a computer, comprising:

predicting a future traffic amount of a communication link on the basis of prediction information used to predict the traffic amount;

calculating prediction accuracy on the basis of the traffic amount of the communication link in a first period and the actual traffic amount of the communication link in the first period;

determining a threshold value used to determine whether or not congestion will occur on the basis of the prediction accuracy and a transmission ability of the communication link;

estimating the number of terminals in communication which is the number of terminals that are performing communication through the communication link;

calculating a transmission duration time of the traffic per terminal on the basis of the traffic amount in a second period, which is a period later than the first period, the number of terminals in communication, an average rate per terminal, a transmission cycle of traffic, and a transmission interval of the traffic;

determining whether or not the congestion will occur on the basis of the traffic amount in the second period and the threshold value determined in the threshold value determination step; and

determining whether or not to perform path switching to reduce the traffic amount of the communication link, due to which occurrence of the congestion is predicted, on the basis of a congestion duration time calculated on the basis of the transmission duration time in a case where it is determined that the congestion will occur, and providing an instruction to perform the path switching to a transfer device configuring a communication network in a case where it is determined to be necessary to perform the path switching.