On Relay Selection Approaches in Bluetooth Mesh Networks

Bluetooth Mesh (BM) is a new communication standard, which is designed for the upcoming Internet of Things. It builds on the Bluetooth Low Energy (BLE) protocol and allows devices to extend the range and create a mesh network. BM introduces a publisher/ observer structure where a publisher node can broadcast a packet, known also as an advertisement, and all observers can receive the packet. Typically, in BM networks flooding is used to propagate the advertisements. Flooding is known to suffer from broadcast storm problem and be nonreli-able. To improve packet delivery ratio we propose an approach where only a few nodes, relays, are involved in packet forwarding. Selection of the relay nodes, which is a focus of the paper, is a nontrivial task: on the one hand, a minimization of number of relays is desired, on the other hand, using a minimum dominated set would not provide redundancy. We consider three different relay selection mechanisms and develop their extensions that are capable to operate in a distributed fashion. Their performance is evaluated via extensive simulations.