Research On Energy-saving MAC Protocols In WSN For Internet Of Things

With the development of IOT (internet of things), people propose more and morerequirement about the wireless sensor networks performance for its key technology. It notonly needs to meet the reliability of the networks, but also put forward higher requirement ofthe network life. A key factor influencing the network life is the network energy-limited.Therefore, energy-saving has become a key problem for the wireless sensor networkscommunication protocol design.The MAC protocols on the data link layer in wireless sensor networks, is deeply studied.In this paper, the sensor nodes perceived data exists a certain reliability and spatial correlation,moreover, sensor networks load in the actual application environment is always changing.Two new energy-saving MAC protocols are proposed, it is the significant meaning forextending network life.Firstly, an energy-saving MAC protocol based on perceived data reliability and spatialcorrelation is designed. The establishment of a circle-annular spatial correlation modeldeduces the relationship between the distortion and node selection. According to thereliability of the nodes collected data in this model, the sensor nodes are screened. For thenodes with good sensed data, attributes them high priority in the channel competition, at thesame time the nodes with poor sensed data, the transmission data is brought down. To avoidtransmission data collision, we adopt a new retreats method. All these processing ensure thereliability and effectiveness of the data in the networks.Secondly, an energy-saving MAC protocol based on network load mutations is designed.The protocol considers the redundancy problem between the sensor nodes data, takes differentscheduling methods for different levels of nodes. According to the network load mutation,dynamically adjust to the detective and dormancy time. This method solves the unfairness ofthe network energy and delay, and can better satisfy changes in the complex networkenvironment.In Linux system, we use the NS2 to simulate the two new energy-saving MAC protocols.Though comparison analysis of energy consumption ,time-to-time delay and throughput , thetwo new protocols show better performance and have particular outstanding in energyconservation.