US Patent 9106330 Wireless communication apparatus and interference avoidance method

A wireless communication apparatus in a first wireless system is provided with first, second and third units, and a controller. The first unit transmits frames over a frequency channel using a short or long IFS as compared with a specific one used in a second wireless system with a communication range wider than the first wireless system. The second unit receives frames over the channel. The third unit determines an error characteristic in the received frames and/or a busy status of the channel. The controller controls at least either one of whether to change the frequency channel or not, and whether to change a duration of an interframe space or not.