GPS-Free Maintenance of a Free-Space-Optical Link Between Two Autonomous Mobiles




Full duplex, free-space-optical (FSO) communication can provide optical-level wireless communication speeds and has several advantages over conventional radio frequency (RF) wireless technologies. FSO communication has better throughput, enhanced spectrum utilization, lower interference, and addresses the wireless and capacity crunch faced by legacy RF technologies. However, FSO receivers are highly directional, and require establishment and maintenance of line-of-sight (LOS) between each other. Researchers at the University of Nevada, Reno have developed a method and to maintain an FSO link between two autonomous mobile nodes using mechanically steerable transceivers.



Our researchers have developed a method for neighbor discovery between a receiver and transmitter located on autonomous mobile nodes. This method does not require use of a GPS, and uses only optical methods. Issues with RF, microwave transmitters, and laser communication devices are addressed and simplified using this technique. An LOS connection is established and maintained using FSO transceivers mounted on mechanically steered heads which rotate and stop to maintain a communication link. Clockwise rotations enable for a more likely connection, and upon locking, information on location is communicated between the two devices for prediction of the next location to maintain or reestablish a connection. This technique was modeled using radio-controlled cars and in MatLab simulation software. This method was proved effective in maintaining a connection between two points when accounting for introduced variation and noise similar to real world implementation. Use of various sensors including an accelerometer, gyroscope and magnetometer tracts and transmits vector information.



•       Our method addresses the highly directional LOS requirements of FSO communication

•       Our method does not require use of a GPS, which requires a clear view of the sky

•       Our method uses only a visual communication system and ultimately uses less hardware than other technologies


Patents and Publications

•       WO 2017/200948 A1 - Directional Link Discovery and Maintenance Between Mobiles

•       GPS-Free Maintenance of a FSO Link Between Two Autonomous Mobiles

•       LOS Discovery for Highly Directional Full Duplex RF/FSO Transceivers




UNR16-003 and UNR16-004

Patent Information:
For Information, Contact:
Shannon Sheehan
Manager, Technology Commercialization
University of Nevada, Reno
Mahmudur Khan
Murat Yuksel