Research On Performance Improvement Method Of Low Power Wide Area Network Based On LoRa

Low-power wireless communication technology is an important part of modern IoT communication technology and an important supplement to traditional IoT communication technology.The emergence of low-power wide-area network(LPWAN)represented by LoRa(Long-range Radio)solves the problem of traditional IoT communication technology,such as high power consumption,short transmission distance,high cost and complex networking problem.Low power consumption is the most significant feature of LPWAN and system power control is the most important research content.It is the necessary process for network networking that try to properly configure the parameters of the network for different application environments,to reduce the wake-up time of the devices,and reduce the power consumption of the system.Based on LoRa technology,this paper studies the key parameter configuration problems in low-power communication networks,including device-to-gateway access control parameter calculation,system-specific transmission control parameter configuration,and LoRa system capacity enhancement.Firstly,device-to-gateway access process control in LoRa networks.This paper proposes to use ACB(Access Class Barring)mechanism to solve the congestion problem in a massive access procedures in the LoRa network.The system is set as a model of devices coexistence of two different priorities to achieve more accurate access control of the devices,and a reasonable access control factor is set according to the system state to limit the number of devices simultaneously initiating the access process,and the maximum successful access rate required by the access priority is satisfied;Secondly,calculation of LoRa network model and transmission control parameters.Established the LoRa network model,according to the successful transmission requirement of LoRa device data,it is proposed that the received signal power at the gateway is greater than the receiving sensitivity,and the signal to interference ratio(SIR)of the signal is greater than the relative threshold of the signal.The system achieves the successful average Successful Transmission Probability(STP)by Spreading Factor(SF)allocation scheme: Probability Matching Scheme(PMS),dynamically adjusts the SF used by the amount of devices in different time slots,in the system,it makes the average successful transmission probability of the system reaches the highest and decreases data retransmission probability which is caused by signal interference between devices,improving data transmission efficiency and reducing power consumption;Finally,directional Antenna and LoRa Network Capacity.The directional antenna is used to weaken the signal interference between devices,to improve the system capacity,solve the problem of the decrease of the signal-to-interference ratio and the low data transmission efficiency caused by the increase of the device density,and it is clear that the signal interference level in each sector is different when the directional antennas are used with different angles.The SF usage interval needs to be reconfigured according to different direction angles to maximize system capacity.