Carrier Sense Multiple Access with Collision Avoidance Based on the Indication Information

According to both the basic mode and RTS/CTS mode of DCF in existing standards, a novel mechanism of Carrier Sense Multiple Access with Collision Avoidance based on the indication information is proposed, which is divided into three improved modes. The improved basic mode and the improved RTS/CTS mode 1 with better adaptability to the length of data frame are put forward as two improved modes and it’s suggested that the threshold of the data frame length could be set under the condition of fixed transmission rate of data in the network. Then according to the relationship between the length of data frame and the threshold, dynamic switch between two improved modes could be implemented. As a result, the processing time of collision will be shortened and additional system overhead caused by random back-off will be reduced. The simulation results of NS2 show that Carrier Sense Multiple Access with Collision Avoidance based on the indication information has better system performance compared with the conventional DCF mechanism.