The future of manufacturing, agriculture, distribution, healthcare, and virtually every other labor-intensive endeavor is robotic—a multitude of autonomous, mobile, robotic systems. One of the many problems this will bring is the coordination of independently-navigating robots in limited spaces. Communication is the key to coordination. Fixed-position and mobile robots can identify and localize each other in real-time using pulses of visible or infrared light, synchronized with wireless messages in 5G or 6G. A fixed-position robotic assembly device can identify a mobile robot bringing raw components, by exchanging synchronized pulses and messages. Busy robots in a distribution center can avoid collisions and improve throughput by coordinating with other proximate robots, using the communication tools provided herein. Fixed-position robots can enforce boundary conditions and provide oversight, keeping innumerable mobile devices in-lane and on-task. Many other aspects and applications are provided.