A Hierarchical BLE Mesh Network for IoT and Performance Analysis

Abstract

Bluetooth Low Energy (BLE) mesh which is the latest and the most innovative network technology has deeply changed the connection mode among massive BLE devices in Internet of Things (IoT). The study on the architecture and networking is quite necessary for the development of BLE Mesh. In IoT, the BLE devices are often used for voice, audio and data services. To satisfy the demands of diverse services and the mobility of the nodes, a hierarchical BLE mesh network (HBMN) architecture is proposed consisting of Hub Layer, Mesh Layer and User Layer. The HBMN architecture combines the star-network and mesh topology. Besides, the networking process of HBMN from the unprovisioned devices is also investigated in this paper. Moreover, two important performance measures have been analyzed and derived including networking time and single-hop delay. Finally, the access delay of one node is measured on the nRF52832 hardware platform. In addition, the networking time and single-hop delay of HBMN are evaluated and compared with the traditional BLE scatternet. The results show that the average single-hop delay of the BLE scatternet is 1.74 times as long as HBMN averagely and HBMN has a superior performance on the networking time when the network has a large number of devices.