SHENYANG INSTITUTE OF AUTOMATION, CHINESE ACADEMY OF SCIENCES
The present invention relates to a two-stage adaptive frequency hopping (AFH) method facing a clustered wireless sensor network (WSN). The method includes following steps: establishing a clustered WSN; defining a super frame structure based on IEEE 802.15.4 according to the topology structure of the above clustered WSN; expanding the content of the beacon frame load based on the original beacon frame format of the IEEE 802.15.4 media access control (MAC) layer; according to the above super frame structure and the expanded beacon frame of the IEEE 802.15.4 MAC layer, implementing the process of two-stage AFH for network nodes. The use of the clustered WSN in the invention enlarges the network scope, reduces the difficulty of maintenance and management, and improves the system flexibility. The design of the two-stage frequency hopping method ensures the compatibility of IEEE 802.15.4 and the reliability of the system. The beacon frame load is based on IEEE 802.15.4, thus during the channel handoff, there is no need to design a special frame for broadcasting channel distribution results. The network design is simplified, the number of frame for control is reduced, and the throughput of the network is improved.