Patent ID: 8031737

Claim:
A method of establishing a sub-network by a device of a first wireless network, the method comprising: searching whether another channel other than a first channel is available, the first channel comprising a first high-rate physical channel and a first low-rate physical channel, wherein the first high-rate physical channel and the first low-rate physical channel exist within a first frequency band and are currently used in the first wireless network which comprises a coordinator; switching from the first channel to a second channel based on the searching result, the second channel comprising a second high-rate physical channel and a second low-rate physical channel which exist within a second frequency band among at least one available channel; establishing the sub-network on the second channel to broadcast a beacon on the second low-rate physical channel, wherein the coordinator continues to broadcast a beacon on the first low-rate physical channel in the first wireless network after the sub-network is established on the second channel; and returning to the first channel periodically for a certain period to receive a beacon transmitted from the coordinator and an unreserved region following the beacon, wherein the device comes back to the second channel after receiving the beacon and the unreserved region on the first channel to communicate with at least one device in the sub-network.