Cooperative medium access control protocol based on double priority selection

The invention discloses a cooperative medium access control protocol based on double priority selection. An intelligent power grid architecture is divided into a home area network (HAN), a neighborhood area network (NAN) and a wide area network (WAN) at three levels through the protocol, and the protocol is located in the NAN range. The protocol includes the steps that during first priority selection, a source node selects three optimal candidate relay nodes according to a stored relay node information table, and the selection principle is based on recorded cooperative speeds Rcoop; during second priority selection, whether an intelligent relay SR exists in the candidate relay nodes or not is detected, if yes, the SR is selected as the final relay node, if not, according to the back-off principle, the three candidate relay nodes strive for sending RTH grouping to participate in relay, and the lengths of the back-off time are inversely proportional to respective latest cooperative speeds Rcoop.