Patent ID: 8855659

Claim:
A transmission device comprising: a transmission power setting unit configured to respectively set a main transmission power for transmitting a main sound signal indicating a main sound and a subsidiary transmission power for transmitting a subsidiary sound signal that produces a predetermined sound effect pertinent to the main sound signal; and a first communication unit configured to transmit the main sound signal and the subsidiary sound signal on time division channels using the same frequency band, based on the main and subsidiary transmission powers set by the transmission power setting unit, wherein the transmission power setting unit sets the main transmission power to a first reference value, and sets the subsidiary transmission power to a second reference value smaller than the first reference value; wherein the transmission power setting unit respectively adjusts the main and subsidiary transmission powers based on the number of negative acknowledgement packets for each of the time division channels that are received by the first communication unit during a predetermined period; wherein the transmission power setting unit respectively compares the number of the negative acknowledgement packets for each of the time division channels received by the first communication unit during the predetermined period with a predetermined lower limit, and when the number of the negative acknowledgement packets is equal to or less than the predetermined lower limit, sets a transmission power for a sound signal transmitted on the corresponding time division channel to a smaller value than a set value; and wherein the transmission power setting unit respectively compares the number of the negative acknowledgement packets for each of the time division channels with a predetermined upper limit, and when the number of the negative acknowledgement packets is equal to or more than the predetermined upper limit, sets a transmission power for a sound signal transmitted on the corresponding time division channel to a larger value than the set value.