Communication device and communication signal generation method

A communication device, comprising:

• a processor;
• and
• a memory storing a program and data,
• wherein the program, when executed by the processor, causes the processor to perform:
• selecting a mode from a plurality of modes used for communication with another communication device, wherein the plurality of modes each defines one or more channels;
• selecting a channel from the one or more channels defined by the selected mode;
• waiting for a control signal from the another communication device via the selected channel;
• and
• when not receiving the control signal from the another communication device via the selected channel within a defined period of time, changing the selected channel to another channel to wait for the control signal,
• wherein,
• the plurality of modes include a first mode defining at least one first channel and a second mode defining at least one second channel,
• a frequency band of the first channel is different from a frequency band of the second channel,
• a number of subcarriers in the first channel is the same as a number of subcarriers in the second channel, and
• a number of the first channels(s) in the first mode is different from a number of the second channel(s) in the second mode.