Beacon-Based Time Synchronization Protocol Design for Layered Ultraviolet Communication Network

To construct time slot synchronization for further resource management of ultraviolet (UV) networks, we propose a slot synchronization protocol based on flooding time and power optimization. Beacon sequence is applied to broadcast slot information without exchanging messages. Firstly, we propose slot synchronization schemes based on beacon sequence for two cases, with both multiple initialization nodes and a single initialization node. Then, we investigate the network synchronization accuracy with non-overlapping and overlapping beacons, as well as the synchronization accuracy of the entire network. Based on the network synchronization accuracy results, we propose power optimization to expand the synchronization range and enhance the synchronization probability. Numerical results show that power optimization can approximately achieve 18% higher synchronization success probability and 15% larger network synchronization range. Moreover, the proposed synchronization scheme is approximately 10 time periods shorter than meshed emergent firefly synchronization (MEMFIS), with approximately 40% lower network synchronization error.