Researchers from Nanjing University of Posts and Telecommunications have developed a prototype mobile all-light communication network capable of maintaining seamless connectivity across air, land, and underwater environments, even with communication nodes on moving vehicles.
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This innovation has the potential to revolutionize data exchange in dynamic and challenging conditions, supporting applications such as navigation, emergency response, research, and commercial operations. The findings were published in the journal Optics Express.
Our all-light wireless network combines different light sources to ensure uninterrupted connectivity while also dynamically aligning optical paths between moving nodes. This enables two-way real-time data transmission, ensuring reliable communication and data exchange within and across networks, regardless of the environment.
Yongwin Wang, Research Team Leader, Nanjing University of Posts and Telecommunications
As part of the study, the researchers demonstrated that two prototype communication devices deployed separately on moving vehicles can establish bidirectional light transmission between network nodes across both air and underwater environments.
Our new wireless optical communication system could enable continuous connectivity for essential mobile nodes like drones, vehicles, and ships. This could transform the way mobile networks operate.
Yongwin Wang, Research Team Leader, Nanjing University of Posts and Telecommunications
Solving the Alignment Challenge
The new study builds on earlier experiments where the researchers successfully demonstrated all-light communication using fixed communication nodes.
In this work, we solve the challenging issue of dynamic optical path alignment to achieve mobile full-duplex light communication. We also provide a new network architecture that ensures even and accurate comprehensive connectivity across all its parts while simultaneously supporting fast, two-way data exchange.
Yongwin Wang, Research Team Leader, Nanjing University of Posts and Telecommunications
The new system integrates mobile green light communication under the Transmission Control Protocol/Internet Protocol (TCP/IP) framework with blue laser communication for data exchange between underwater vehicles. It also incorporates a deep ultraviolet light communication system for "solar-blind" wireless data transmission, which prevents interference from solar radiation, and an 850-nm laser diode communication system for data reception.
All communication systems are interconnected via Ethernet switches, allowing access to various terminals, such as sensors and personal computers.
To enable bidirectional light transmission across air and underwater environments between moving network nodes, precise optical alignment is crucial. The researchers achieved this by developing an image identification module and a full-duplex light communication module, both mounted on a three-axis gimbal stabilizer.
The image identification module captures real-time images of light from other communication systems and provides feedback signals to adjust the gimbal stabilizer dynamically. This setup ensures continuous optical path alignment between the communication ends, facilitating mobile bidirectional data transmission under the TCP/IP scheme.
Additionally, the researchers designed a comprehensive mapping network architecture to enable seamless, balanced data flow across all nodes. This architecture ensures real-time, bidirectional data transmission, allowing information to be sent and received simultaneously without delays or data loss.
Air-Water Connectivity
The researchers demonstrated their new network by developing two green-light communication devices, each equipped with image identification modules mounted on three-axis gimbal stabilizers and installed on separate moving vehicles.
Testing took place on an outdoor lawn during both nighttime and full sunlight, as well as in an indoor water tank. The researchers successfully demonstrated bidirectional light transmission between mobile network nodes across air and underwater environments, achieving a maximum modulation bandwidth of 4 Mbps—sufficient for video and audio transmission.
The system also enabled seamless video communication across both environments and provided internet access via a Wi-Fi modem.
Looking ahead, the researchers aim to establish an all-light communication network that integrates wired modes with wireless moving and fixed nodes, utilizing light sources of various wavelengths. They also plan to combine mobile all-light communication with radio, sonar, and gas communication technologies to create a future, fully integrated communication network.
Wang said, “In the future, we could combine on-chip light communication with free-space light communication to create an all-light interconnection communication network, which could transmit and receive data across space and chip environments for seamless connectivity. Such sophisticated all-light interconnection networks could be used to develop advanced information processing and computing systems.”
Journal Reference:
Liu, P., et al. (2024) Mobile all-light communication network. Optics Express. doi.org/10.1364/oe.543730.