Chinese Academy of Sciences

Yutuo Yang

Haibin Yu

Wei Liang

Shuai Liu

Xiaoling Zhang

Meng Zheng

Manyi Du

The present invention relates to cognitive wireless sensor network technologies, and in particular to a medium access control method for a cognitive sensor network based on broadcast preamble sampling. A cognitive node in the cognitive sensor network adopts a periodical dormancy-awakening mechanism. Firstly, a state of a primary user is judged by using a spectrum sensing technology. If the primary user is not active, a data sending node establishes a communication link by using a broadcast preamble code. Each neighbor node simultaneously considers information of hops from a gateway according to an awakening order, and independently determines to serve as a relay node for forwarding data. Furthermore, a transmission conflict between the cognitive node and the primary user may be caused due to return or missed alarm of the primary user. The present invention adopts a retransmission mechanism based on confirmation to ensure transmission reliability of data packets. The present invention is independent of a common control channel, and can realize reliable access of the cognitive sensor network for an authorized frequency band at low overhead.

Medium access control method based on broadcast preamble sampling for cognitive sensor network

The present invention relates to a TDMA access method and device based on multiple access points. According to the problems that the existing method cannot simultaneously satisfy the demands of timeliness and reliability in actual industrial application and has low resource utilization rate, the present invention takes full consideration of the transmission characteristics and industrial automation application characteristics of wireless networks, and provides a TDMA access method and device based on multiple access points. The main ideas of the method in the present invention are: the multi-access point redundant communication manner is adopted to improve system reliability, beacon frames of multiple access points are utilized to perform time synchronization so as to improve synchronization precision, confirmation messages are fed back with regard to reliable access points to reduce the number of retransmissions, and a modularized multi-access point device design method is adopted to lower the difficulties of device maintenance and management.

TDMA access method and device based on multiple access points

Growing community of inventors

Liaoning, China

Yutuo Yang