sensors Review Bluetooth Low Energy Mesh Networks: A Survey Seyed Mahdi Darroudi and Carles Gomez * Department of Network Engineering, Universitat Politècnica de Catalunya, Castelldefels 08860, Spain;
[email protected] * Correspondence:
[email protected]; Tel.: +34-93-413-7206 Received: 15 May 2017; Accepted: 20 June 2017; Published: 22 June 2017 Abstract: Bluetooth Low Energy (BLE) has gained significant momentum. However, the original design of BLE focused on star topology networking, which limits network coverage range and precludes end-to-end path diversity. In contrast, other competing technologies overcome such constraints by supporting the mesh network topology. For these reasons, academia, industry, and standards development organizations have been designing solutions to enable BLE mesh networks. Nevertheless, the literature lacks a consolidated view on this emerging area. This paper comprehensively surveys state of the art BLE mesh networking. We first provide a taxonomy of BLE mesh network solutions. We then review the solutions, describing the variety of approaches that leverage existing BLE functionality to enable BLE mesh networks. We identify crucial aspects of BLE mesh network solutions and discuss their advantages and drawbacks. Finally, we highlight currently open issues. Keywords: Bluetooth Low Energy; Bluetooth Smart; mesh networks; survey; Internet of Things; IoT; 6LoWPAN; 6Lo; Bluetooth Smart Mesh 1. Introduction Bluetooth Low Energy (BLE), also marketed as Bluetooth Smart, has emerged as a major low-power wireless technology [1]. Leveraging a design that can reuse classic Bluetooth circuitry to a large extent, BLE has gained a dominant position in smartphones. This allows low-energy communication between the latter and other devices such as sensors, actuators, wearables, etc.