- Optical inter-satellite links are set to revolutionize satellite communication, offering higher bandwidth and improved data transfer speeds compared to traditional RF links.
- They provide more reliable and precise communication, especially between LEO satellites and GEO payloads.
- Leveraging the reliability of microwave links and the high bandwidth of optical communication to enhance satellite connectivity.
- These technologies are crucial for scaling satellite constellations, supporting diverse applications in sectors like communications, observation, and navigation.
Scaling Up Deployment of Optical Intersatellite Links
Optical intersatellite links leverage laser technology to achieve unprecedented high-throughput data transfer. Unlike the wireless RF spectrum, which includes bands like S-band, Ka-band, and Ku-band, OISLs utilize the infrared portion of the electromagnetic spectrum—ranging from approximately 300 GHz to 430 THz—offering exceptional bandwidth. This vast spectrum enables the encoding of significantly more data into the waveform. Compared to RF links, OISLs gather more energy, allowing for smaller, lighter, and more power-efficient laser transmitters and detectors.
Optical ISLs have been in use for a long time and are already deployed at scale on the Starlink platform, with each current-generation satellite equipped with three 200Gbit/s OISLs—amounting to approximately 10,000 OISLs in orbit today. Other major players, including Kuiper, Telesat Lightspeed, and Rivada Space Networks, are also adopting ISLs at scale.
With their extremely high bandwidth and secure connections, optical communications are driving optimism around laser-linked satellite constellations. The growing number of companies entering this field reflects the rising interest in these technologies. Furthermore, the precision of laser transmissions minimizes disturbances, enabling much narrower and more reliable connections between Low Earth Orbit (LEO) satellites and payloads in Geostationary Orbit (GEO).
However, as international players continue to advance their capabilities, the UK must strengthen its position in this market to establish a sovereign, high-capacity (Tbit/s-class) supply chain and maintain a competitive edge.
Satellite constellations—networks of multiple satellites working together for communication, observation, or navigation—play a critical role in these advancements. Since ground stations are typically located in fixed, constrained areas, establishing robust inter-satellite links (ISLs) is essential for enabling Non-Terrestrial Networks (NTNs) and ensuring seamless connectivity.
Towards Multi-Orbit Communications
Microwave and optical inter-satellite links represent the forefront of satellite communication technology. While microwave links provide reliable, robust communication, optical links offer unparalleled data transfer speeds and enhanced security. As satellite networks grow and missions become more ambitious, the integration of these technologies will define the future of space-based communications.
Hybrid systems that combine RF and optical technologies are emerging as a balanced solution, addressing both technological risks and cost concerns. By leveraging the reliability of microwave links for critical communication and the high bandwidth of optical links for data transfer, these systems provide resilience and efficiency.
Advancements in satellite tracking and laser pointing accuracy are further addressing the alignment challenges of optical communications. Large constellations of interconnected satellites will increasingly rely on both microwave and optical technologies, creating robust and efficient space-based communication networks. Through continued innovation, these technologies will unlock new possibilities, driving the next generation of satellite connectivity and exploration.
Next Steps
The next steps involve continued development and integration of hybrid inter-satellite link (ISL) systems that combine both microwave and optical technologies. This includes rigorous testing in real-world satellite environments to optimize performance, reliability, and efficiency. Special attention will be given to improving satellite tracking and laser pointing accuracy to overcome alignment challenges with optical links. Collaboration between space agencies, satellite manufacturers, and telecom companies will be crucial to establish standardized protocols and regulatory frameworks for seamless integration of these systems into global space communications networks.
Looking ahead, the scalability of large satellite constellations with interconnected ISLs should be explored further to support a range of applications, including high-speed data transfer, secure communication, and global coverage. Additionally, the expansion of ground-based infrastructure to support optical and microwave ISLs, as well as fostering public-private sector engagement, will be key to accelerating the rollout of these advanced communication technologies. This collaborative approach will drive the next generation of satellite connectivity, positioning the industry to meet future demands for reliable, high-capacity space-based communication systems.
Optical Communications Roadmap
This is a year-long initiative with quarterly events, culminating in a published roadmap by year-end. As a techUK-led project, participation is primarily limited to members and government stakeholders. If this opportunity sounds interesting, get in touch with [email protected]
Tales Gaspar
Tales has a background in law and economics, with previous experience in the regulation of new technologies and infrastructure.
Rory Daniels
Rory joined techUK in June 2023 after three years in the Civil Service on its Fast Stream leadership development programme.
