FSO is a major candidate to complement traditional radio frequency or RF networks and can help solve the capacity crunch faced by RF wireless technologies. It uses the unlicensed optical spectrum and can easily reach very high modulation speeds (tens of Gbps). Compared to RF, it can provide much higher bandwidth to transfer large volumes of data. The high directionality of FSO communication systems provides high spatial reuse and larger network capacity. FSO can also provide connectivity in unfavorable conditions, e.g., presence of RF jamming or interception. Despite the advantages over RF communication, the major challenge faced by FSOC is its vulnerability against mobility. Mobile FSOC requires effective maintenance of LOS. In the first part of this project, we proposed a novel scheme showing the feasibility of maintaining FSO links between two mobile robot cars with minimal disruption using mechanically steered transceivers and a simple auto-alignment mechanism. We also presented a prototype implementation of such mobile FSO nodes. We demonstrated that using such mechanical steering capability to control the rotation of the transceivers, the problem of LOS maintenance can be dealt with effectively without global positioning system (GPS).
Equipping Unmanned-Aerial-Vehicles (UAVs) with high-speed FSO transceivers can enable a large set of applications involving transfers of very large wireless data. UAVs with several sensors generate a lot of data which may require to be delivered to either another UAV or a ground station. The higher data rate required for communication links to transmit more information between UAVs triggered the idea of employing FSO transceivers to meet the increasing demand. UAV-based FSO communication is a challenging but emerging technology. So, in the second part of this project, we focused on establishing communication links among UAVs or drones equipped with FSO transceivers in a 3D wireless ad hoc network. We proposed schemes for FSO link maintenance between flying drones/UAVs equipped with laser and LED transmitters.
Conrad, Mitchell, Brody Hageneder, Michael Geyer, Deborah Amao, James Moscola, and Mahmudur Khan. "Reliable Communication in a Computer Vision Enhanced Free-Space-Optical Mobile Network." Proceedings of IEEE International Conference on Computing and Information Technology (ICCIT), Pages 1-6, 1944-1949, Cox's Bazar, Bangladesh, December 2024.
Bhunia, Suman, Yicheng Qian, and Mahmudur Khan. "Electronically Steerable Mobile Optical-Wireless Mesh-Network." Proceedings of IEEE International Systems Conference (SysCon), Pages 1-6. Motreal, Canada, 2024.
Gartrell, Riely, Ryan Black, Kyle Bush, Mahmudur Khan, James Moscola, and Joshua Gilbery. "Reliable Communication in a Multi-Transceiver Mobile Optical Wireless Network." Accepted, IEEE Military Communications Conference (MILCOM), Boston, Massachusetts, October-November 2023.
Khan, Mahmudur, Murat Yuksel, and Garrett Winkelmaier. "GPS-Free Maintenance of a Free-Space-Optical Link Between Two Autonomous Mobiles." IEEE Transactions on Mobile Computing, 16(6), pp. 1644-1657, June 2017.
Khan, Mahmudur, Garrett Winkelmaier, and Murat Yuksel. "In-band Autonomous Maintenance of Mobile Free-Space-Optical Links: A Prototype." Proceedings of IEEE ICC Workshop on Optical Wireless Communication (OWC), Pages 157-162, Kuala Lumpur, Malaysia, May 2016.
Khan, Mahmudur, and Murat Yuksel. "Autonomous Alignment of Free-Space-Optical Links Between UAVs." Proceedings of ACM MobiCom Workshop on Hot Topics in Wireless (HotWireless), Pages 36-40, Paris, France, September 2015.
Khan, Mahmudur, and Murat Yuksel. "Maintaining a Free-Space-Optical Communication Link Between Two Autonomous Mobiles." Proceedings of IEEE Wireless Communications and Networking Conference (WCNC), Pages 3196-3201, Istanbul, Turkey, April 2014.