Patent ID: 8233497

Claim:
A communication control apparatus that controls radio communications with at least one other communication device through a relay device, the communication control apparatus comprising: a controller that notifies a data transmission to the relay device, and performs the data transmission to the relay device when the controller receives a response to the notification from the relay device indicating that the data transmission is possible, and stops a data transmission when the controller receives a response to a notification made by the other communication devices from the relay device; a collision conjecture processor that conjectures a collision of frames at the data transmission in accordance with a predetermined condition; and a threshold value control processor that sets a threshold value to determine an assertion or a negation of the controller in accordance with a result of the conjecture of the collision, the threshold value control processor including: a frame collision conjecture processor that discriminates whether or not a first condition for deciding the collision of the frames and transmission/reception states of the frames correspond, conjectures that the frame collision has occurred in a case where the frame transmission or the frame reception states satisfy the first condition, and counts the number of times of occurrences of the frame collisions; a threshold value determination processor that determines a new threshold value that corresponds to the number of times of occurrences of the frame collisions as counted by the frame collision conjecture processor in accordance with a second condition for a threshold value alteration; and a threshold value setting processor that alters a threshold value stored in threshold value storage unit to the new threshold value determined by the threshold value determination processor.