In this proximity safety system, an active (battery powered) RFID transponder should be carried by each worker and a sensor should be mounted on mobile plant. The sensor poses an alert-parameter around the mobile plant machine using a High-Penentration Low-Frequency Radio, which triggers the transponder to release a far-range microwave signal to alert the dirver of machines.

Benefits
．Not affected by metal objects or human body
．Unaffected by light source, line of sight, or temperature
．No blind spots
．High reliability

Applications
．Mobile plant

Project References
．Liantang Boundary Control Point (Hong Kong)