The Research And Design Of Connected Low-Power BLE Mesh Networking

With the increase of Internet of Things devices,networking control of devices has become the focus of attention.Bluetooth Low Energy(BLE)Mesh is widely used in indoor Internet of Things,Internet of Vehicles,Industrial Sensors and other fields due to its low power consumption and self-organizing.At present,the battery capacity of smart portable devices is limited.In order to improve their endurance and make BLE Mesh more widely used,reducing the power consumption of existing Mesh schemes becomes the key of research.In order to reduce the overall power consumption of BLE Mesh network,this paper will design an energy-balanced ad hoc network Mesh scheme with simple mesh structure,based on the existing connected BLE Mesh.Firstly,we study the networking mode,network topology and routing algorithm of current BLE Mesh scheme,and analyze the power performance of different schemes.Then,aiming at resolving the problems of too large scale of message retransmission and too high power consumption in the whole network,we design the the Mesh scheme of this paper: when networking,low-power nodes are placed outside the network,simple mesh network is formed by merging subnets,which reduces the networking time and the quantities of BLE connections;when establishing routing,energy parameters are introduced to modify the routing and select the path with more residual energy,which avoids the low-energy nodes deplete energy quickly and leave the network.when transferring data,the nodes switch routes according to the residual energy to balance the energy consumption of the network.Then,based on MATLAB and OMNeT++ respectively,the networking scheme and routing algorithm are modeled to simulate networking time,network topology and routing handover.Based on TI's CC2640R2 F development platform and the BLE5 protocol stack,this paper implements the energy-balanced ad hoc Mesh scheme of the simple mesh structure proposed.The experimental results show that the networking scheme of this paper can automatically construct a simple mesh network,and the routing can switch according to the node energy.The average operating current of a node with three connections in the network is 112μA,and the average operating current of a single connected node is 45μA.Both nodes are powered by a 250 mAh CR2032 battery and can work for 93 and 231 days respectively.The results show that the Mesh network nodes in this paper work long hours and meet the low power requirements of Internet of Things.