Fast channel switching technique for interference avoidance with 5 GHz dual channel wireless LAN

In 5 GHz wireless LAN, a DFS (dynamic frequency selection) technology must be implemented to avoid interference from radars. However, in accordance with Japanese regulations, communication is interrupted for 60 seconds by the radar scan after communication frequency switches. We addressed this challenge by developing a novel wireless access point possessing two RF modules. Preparing another channel in the access point enables fast and stable frequency switching at the initiative of a station. Measurement results of the prototype system showed a frequency switching delay time of 11 milliseconds under the DFS environment.