A control apparatus that controls the communication period length of a signal transmitted by radio obtains the first radio quality regarding the first signal and the second radio quality regarding the second signal when spatially separating and transmitting the first signal and the second signal in parallel. The apparatus determines whether the first radio quality satisfies the first level for transmitting the first signal in the first communication period length and whether the second radio quality satisfies the second level for transmitting the second signal in the second communication period length. In a case where the first radio quality does not satisfy the first level or the second radio quality does not satisfy the second level, the apparatus extends the communication period length of a signal having a smaller communication period length.