Design And Implementation Of Friendship Function Of Bluetooth Mesh

The Bluetooth Mesh network is a wireless topology network proposed by the Bluetooth organization.It uses Bluetooth broadcast signals to transmit data,and uses controllable flooding algorithms to control network message forwarding.Nodes' receiving and forwarding messages in the network,enables large-scale networking.In order to expand the application surface,Bluetooth Mesh proposed the Bluetooth Mesh friendship function,which introduces BLE devices into the network topology,and uses the FN(Friend Node)as a bridge between the LPN(low-power node)and the network communication.However,the current friendship function requires manual configuration.Meanwhile,the ineffective manual configuration rises the uncertainty in the performance of FN,which,in some serious cases,will increase power consumption and cause packet loss problems of LPN.This thesis optimizes the power consumption and packet loss problems by implementing the automatic configuration mechanism of the Bluetooth Mesh friendship function.The process will be divided into two stages:Frist,assign FN to LPN;second,establish a friendship relationship between LPN and FN.The first stage will obtain the location information of the LPN in the network,and configure relatively close FN for the LPN according to the location information.So that they can have stable communication quality during the subsequent information exchange process;during the second stage,the network load of the FN will be evaluated and converted into the size of the receiving window.This value will also be used as the time for the LPN to send and receive messages after its periodic sleeps.The LPN will use the window size and signal strength as indicators to select a suitable FN to establish a relationship to ensure its own power consumption and communication quality.This thesis realizes the friendship function based on the Nordic Mesh protocol stack of Nordic Company,and uses the Bluetooth hardware platform based on the n RF52832 minimum system for the analysis.Twenty n RF52832 Bluetooth devices were selected,and the performance of the friendship function and its automatic configuration mechanism was tested under the premise of device networking.The test results show that: compared with the Nordic Mesh friendship function,the power consumption of the optimized LPN reduced by 16%,and the packet loss rate of the LPN is lower than 10 %.Both have reached the expectation.The research results of this paper have certain value for the application expansion of the Bluetooth Mesh friendship function.