Research On MAC Layer Transmission Optimization Based On Outage Probability For Industrial Internet Of Things

The current Industrial Internet of Things(IIo T)contains nodes that carry a variety of different services.The IEEE 802.11ac/ah protocol is commonly used in IIo T to meet the complex transmission requirements.Channel bonding and restricted access window(RAW)mechanism are key technologies introduced in the media access control(MAC)layer of the IEEE 802.11ac/ah.For nodes undertaking different services,the current simple and unreasonable channel bonding and RAW grouping strategy have become the bottleneck restricting IIo T performance.The focus of this paper is to optimize the channel bonding and RAW mechanism.This paper first introduces the outage probability as the index to evaluate the quality of data transmission,and extends the concept of outage probability to signal-to-noise ratio(SNR),analyzes the influence of the factors such as SNR,transmission power and transmission distance on the outage probability,and then derives direct calculation of outage probability.Aiming at the problem of reasonable allocation of limited channel resources in IIo T,this paper proposes the Outage Probability Based Channel Bonding Algorithm(OP-CB),which can be applied to the IEEE 802.11ac/ah network.The OP-CB algorithm evaluates the quality of data transmission before the beginning of data transmissions,and bond multiple channels to the nodes with poor data transmission quality,thereby improving the quality of data transmissions and the performance of the network while ensuring the utilization of channel resources.Aiming at the problem of the problem of grouping nodes on-demand in IIo T,this paper proposes an Outage Probability Based RAW Grouping Algorithm(OP-RAW),which can be applied to IEEE802.11 ah networks.OP-RAW adjusts the length of the RAW time slot according to the node’s traffic requirements and data transmission quality,and then divides the nodes with the same RAW time slot length into the same RAW group.The OP-RAW algorithm enables nodes to complete data transmission in RAW time slots and reduces the waste of channel resources,thereby further improving the transmission efficiency of the network.This paper uses MATLAB to mathematically analyze the introduced outage probability and the proposed OP-CB algorithm.The NS-3 network simulator is used to evaluate the proposed OP-CB and OP-RAW algorithm.The simulation results show that the OP-CB and OP-RAW algorithms can improve the throughput of IEEE 802.11ac/ah networks and reduce latency.For large-scale IIo T with a large number of nodes and a long transmission distance,the OP-CB and OP-RAW algorithms can allocate channel resources more reasonably and improve the transmission efficiency of the network.