Bluetooth Low Energy (BLE) is the prevalent communication protocol for the Internet of Things. However, for time-critical applications requiring time-synchronized multi-hop networks with often multiple node exchanging data at the same time slot, BLE lacks a solution. Instead, we commonly see IEEE 802.15.4 being used with its Time-Slotted Channel Hopping (TSCH) MAC layer.
In this work, we build TBLE, which brings the established TSCH protocol to BLE, enabling BLE to be used for time-synchronized routed mesh communication. We show that in experimental testbed deployments, TBLE achieves similar performance to TSCH, with the possibility for lower average latencies of up to 20%. Moreover, due to the higher spectral efficiency of BLE compared with IEEE 802.15.4 (40 vs. 16 channels), more parallel routed communications are possible with TBLE, further reducing latency and increasing throughput.