DTC-HSR: Distributed Topology Control and Hierarchical Self-Routing for Bluetooth Load Balancing Networks

In this article, a distributed topology control approach with hierarchical self-routing (DTC-HSR) is presented for Bluetooth low-energy (BLE) networks. First, the conventional star piconet is replaced by the designed mesh-ring subnet with better throughput and lower delay. To achieve the goal of load balancing design, two phases, including the leader selection and the topology construction are executed in the proposed approach. In the leader selection phase, each master node discovers its adjacent slave nodes to determine a leader master as a coordinator. In the topology construction phase, the local mesh-ring subnet is first formed and then the global mesh-ring subnets are interconnected into the desired DTC-HSR topology. To form the local mesh-ring subnet, each leader master computes the desired number of piconets with even link connectivity and distributes the piconet connection information for each node to form a mesh-ring subnet. In addition, each master node connects with the other local mesh-ring subnets via its associated bridge nodes, including slave nodes, intrabridges, and interbridges to create the definitive DTC-HSR scatternet. Afterward, a hierarchical self-routing strategy is jointly employed for the DTC-HSR to efficiently deliver routed packets through different mesh-ring subnets. Simulation results demonstrate that the DTC-HSR topology with the even connectivity feature outperforms the dual-ring tree (DRT) and cluster-based mesh (CBM) approaches in terms of network transmission and energy efficiency performances. The DTC-HSR configuration thus achieves efficient topology construction and hierarchical self-routing for load balancing in BLE networks.