Satellite Edge Computing (SEC) revolutionizes data processing by enabling real-time, on-board satellite analysis. It reduces latency, enhances efficiency, and supports diverse applications like disaster monitoring, remote sensing, and IoT integration, fostering seamless communication across Low Earth Orbit satellite networks.

Space based services support the world’s defence forces, financial, information, and secure communications, space based situational awareness in near real time Positioning, Navigation and Timing (PNT) systems, scientific discoveries, and environmental monitoring and have a great potential to benefit all mankind. Rapid advance in space technology have opened up new vistas in application. Traditional satellites have been limited in their scalability due to their exorbitant costs. The advancement of nanosatellite techniques or miniaturisation of hardware has boosted the growth of satellite originated data and their applications. Notwithstanding, the large volumes of data that are captured make it impractical to perform manual analysis on geospatial data. Thus, the need for AI enabled satellites and the concept of edge computing has emerged. Satellite edge computing (SEC) is envisioned to provide in-orbit processing of the sensed data to save the scarce terrestrial satellite communication resources and support mission critical services. In high-resolution earth observation imagery, Low Earth Orbit (LEO) satellites capture and transmit images to ground to create an updated map of an area of interest. However, the amount of data generated can easily exceed the communication capabilities of satellites, leading to congestion and packet dropping. To avoid these problems, the Inter-Satellite Links (ISLs) can be used to distribute the data among multiple satellites in different orbits viz GEO/ MEO/LEO and speed up processing by employing SEC. The details of various space business cases are as depicted below.

Concept of Satellite Edge Computing

Traditionally, satellite networks are based on the bent-pipe architecture, which means satellites merely act as communication relay nodes to transmit data or as sensor nodes to receive instructions from the ground and then send the raw data back to the ground. In a massive constellation, this architecture can result in significant latency, complex routing and other complications. SEC is an emerging paradigm that involves performing computational tasks directly on satellites in orbit instead of sending all the data back to earth for processing. Edge computing or distributed computing has become a critical solution for managing and extracting value from the massive amounts of data being generated in space. As satellite and cloud service providers strengthen their mutual relationship, edge solutions are emerging as a powerful enabler for satellite networks, from the terminal on the ground to the satellite or spacecraft in orbit. Satellites are equipped with powerful computing resources and connect and collaborate to construct SEC networks, which can provide computation offloading services for ground and airborne users. Satellites and IoT devices (such as smartphones, tablets, monitors, etc) can offload computing tasks to SEC networks to achieve low latency, high speed and low cost computing. In the SEC architecture, satellites are equipped with computing capabilities, which can complete computing tasks as edge servers in the network. Since the computational resources are located closer to the data sources, SEC greatly improves communication performance. This enables SEC to provide more diversified services, such as on-orbit data pre-processing, real-time remote sensing image analysis and disaster monitoring.

Edge Computing is Moving to the Center

Edge computing involves processing data closer to where it is generated rather than transmitting it to a remote cloud or ground control station for analysis. This can reduce network resources, cut transmission costs, improve reliability, reduce latency and enhance monitoring over data and applications. Moving computing storage to the edge of the network, closest to users, storage and data devices, has several benefits. Edge computing delivers flexible, near real-time response times for data heavy, AI-driven, stringent data sovereignty, privacy and security of organisations by keeping sensitive data on premise and time critical application This makes it easier to secure data through encryption, increasing consumer trust in data storage, access and management and making it harder for hackers and malware software to compromise data. The combination of low latency, advanced connectivity and enhanced data control makes many IoT use cases more feasible. Instant communication. Instant data. That’s what is possible. Edge computing can improve a wide range of applications that have become central to our work and life. For example, it can process satellite imagery or process satellite navigation signals onboard the satellite rather than transmitting it back to earth for processing. It can be used to run autonomous control algorithms onboard spacecraft, enabling decisions and actions without human intervention. According to Statista, global data creation is expected to reach more than 180 zettabytes by 2025. A recent Raconteur report revealed that 463 exabytes of data will be generated daily over the next two years.

Components of Satellite Edge Computing

A satellite network is a dynamic network composed of nodes and links. In this network, the nodes are the satellites and the links are the communication links between nodes. Duet to the time-variant positions of the satellite, the network topology is changing continually. In the Walker constellation, the links between satellites can only survive about ten or twenty minutes (depending on the satellite’s orbit). The decentralised and distributed nature of edge computing in satellite networks, allowing for more efficient and timely data processing and analysis. The key components of satellite edge computing which work together to provide efficient, real time data processing and analysis in satellite networks, addressing latency, bandwidth and connectivity challenges in the space environment are as given below: –

(a) Satellite. Collects data through various sensors and instruments.

(b) Edge Computing (On-Board Processing). Processes data in real-time on the satellite, reducing latency and enhancing real-time processing capabilities.

(c) Inter-Satellite Links. Enables communication between satellites for data sharing and coordination, facilitating more efficient data processing and distribution.

(d) Ground Station.  Receives downlinked data from the satellite and performs further analysis and processing.

Satellite Edge Computing Architecture

In this article, we propose a classic satellite edge computing architecture, which is composed of GEO satellites as backbone network, LEO or other types of satellites as enhanced coverage nodes and high-altitude platforms to meet the requirements users. As demonstrated in Figure 1, the SEC architecture is composed of five main parts viz the GEO backbone network, operation, algorithms or software and control network and access network.

(a) GEO backbone network. The GEO backbone can be consisting of three to five GEO positions connected as a loop by high-speed laser links. Each GEO position may contain several GEO satellites cooperating as a DSC (Distributed Satellite Cluster) and may acts as computing or processing station for raw data before they are being transmitted to ground control stations. A DSC can be physically composed of communication, navigation, relay or remote-sensing  satellites. The inherent character of GEO satellites (e.g., stationary over the Earth, vast coverage, and mature technology) make them especially suitable for being backbone nodes.

(b) Operation and Control Network. The main tasks of the operation and control network are to maintain the normal operation of various types of platforms, and to provide operational support for users’ service needs. The network is composed of a network control subsystem, application management subsystem, TT&C (Telemetry Track and Command) stations, and gateway stations.

(c) Access Network. The SEC access network can be referred to customers/ users, low-altitude terminals, ground information grid/ ground control stations, navigation satellites, Earth observation satellites, deep-space explorers and satellite systems of other networks.

Task requests uploaded by users on the ground can be continually received by the LEO satellite during its motion. These tasks include the analysis of monitoring data from some sensors, assistance with communication from ocean-going ships, requests for emergency communication from the ground, and analysis of remote sensing images from the satellite itself. Traditionally, the satellite acts as a relay node to transmit the tasks back to the ground central station, i.e., the ground cloud centre, for batch processing. However, as the satellite gains access to more powerful computing resources, it may think about processing tasks on the satellites while in orbit instead of sending them back to the ground cloud centre. The satellites will carry the edge computing servers. The functional components are shown in Figure 2. The satellite edge computing server can autonomously perform work, such as resource allocation and task scheduling, in orbit. This edge computing satellite model, which is close to the users on the ground, may efficiently decrease the backhaul network traffic while also reducing task-processing latency.

Benefits of Edge Computing.  

Satellite Edge networks have several advantages that make them well-suited for handling the large amounts of data generated by space-based systems. Some of the key benefits of SEC include:

(a) Reduced latency. Edge computing can help reduce latency in the satellite network by processing the data near close to its source. This is especially important for applications that require real-time processing, such as remote sensing or disaster response.

(b) Improved reliability. By distributing computing power across the network, edge computing can help improve the reliability and resiliency of satellite systems. This is particularly important for critical applications where downtime or data loss could have serious consequences.

(c) Better security. Edge computing can also help improve the security of satellite networks by reducing the amount of data that needs to be transmitted over long distances. By processing sensitive data locally, edge computing can help minimize the risk of interception or tampering.

(d) Increased efficiency. Processing data at the edge within satellite networks can reduce the volume of data that requires transmission back to ground stations. This can help improve the overall efficiency of the network and reduce costs

(e) Processing Volumes of Data Without Hassle. With IoT devices’ increased computing power, data volumes, and complexities, the burden on existing infrastructure and the network has increased considerably. Additionally, sending all this data to a centralized location creates bandwidth and latency issues. Processing all data in centralized clouds is not feasible; computing at the edge enables processing high-volume data without hassle. According to Gartner, around 75% of the data will be processed outside the traditional data centers or cloud.

(f) Privacy. Sending all the data to the cloud or an on-premise data center is at a high risk of privacy breaches. The networks are also vulnerable to attacks. There is even a chance of data loss while being transmitted to or from the cloud. Such challenges can be easily mitigated with Edge computing. Organizations can decide on what data they can send to the cloud. Critical and confidential data can be processed locally at the edge nodes.

(g) Remote Operations. In remotely placed use cases, there are connectivity issues (low or intermittent connectivity). With edge computing, data processing does not solely rely on network connectivity and can be done remotely, increasing the system’s reliability.

(h) Cost Sensitivity. Edge computing adoption allows one to compute data near the source, avoiding sending data to the cloud at a distance. Reduction in the distance reduces the required bandwidth, and associated infrastructure costs, making edge computing a cost-effective alternative.

Challenges of Edge Computing

Cybersecurity constraints and evolving regulations for device management are significant challenges in the development of satellite edge computing. For cloud computing or data processing received from satellites/ aerial platforms on earth, the initial problems were processing capacity and data security. With the maturation of the Cloud, these problems have been resolved.  Now latency and bandwidth are the most common challenges. The Orbital Data Bottleneck encounters similar patterns: processing power, memory capacity with bandwidth and latency being the most severe. While LEO provides the best case scenario for satellite-earth latency because of its proximity, there is also the future of data growth itself. It is acknowledged that the terrestrial Cloud is constantly racing against increases in data and processing. Edge resources offload the collection and processing of data and minimizes the amount sent to the Cloud. Orbits Edge is extending Edge resources to offload data and analytics, minimizing bandwidth requirements and lowering latency of transmission.

Satellites at the Edge: Applications

The integration of edge computing technology with satellites can enable the development of a wide range of innovative applications. Below, we mention some of them: –

             Weather Observation & Forecasting Climate change. Including the analysis of real-time data to monitor weather and climate status like monitoring global warming for example.

             Precision Agriculture. Satellite imagery and edge computing are used to provide real-time insights on crop health and yield predictions, allowing for more informed decision-making.

             Risk Monitoring & Disaster Response. Satellite data can be combined with edge computing to quickly analyse and respond to natural disasters, such as wildfires or hurricanes.

             Territory Mapping & Urban Growth. Detailed, real-time mapping of urban areas and land use can help city planners make informed decisions about urban growth and development. This can improve infrastructure planning and help mitigate the impact of urbanization on the environment.

             Remote Sensing. Satellites and edge computing can play a vital role in providing real time data analysis.

             Security & Surveillance. This can include monitoring borders and coastlines for illegal activities, tracking the movements of ships and aircraft, and providing situational awareness for military and law enforcement applications.

Key Developments

As the capabilities of satellites and edge computing continue to enhance, the potential applications are everywhere, with the possibility of enabling new industries and driving innovation in existing ones.

(a) Market Growth. The global space based edge computing market is expected to reach $1807.3 million by 2033, growing at a CAGR of 22.64% from 2023 to 2033. The satellite based IoT service market was valued at $279.7 million in 2022 and is expected to grow significantly.

(b) Technological Advancements. The integration of AI and ML algorithms onboard satellites is becoming more prevalent, enabling real-time data processing and reducing the need for data transmission to Earth. In-orbit data centres are being developed to handle and evaluate data generated in space, reducing bandwidth restrictions and transmission delays.

(c) Industry Partnerships and Investments. Companies like Orbits Edge are signing long-term launch agreements to develop high performance computing data centres in low LEO. Startups like AI Edge Labs and AiM Future are securing funding and partnering with established companies to advance edge computing capabilities in satellite networks.

Conclusion

In present geo-political scenario, dominance over space in future, likely to define any nation’s survival as regional or global power. Space assets, Al or satellite edge computing etc are important for the social and economic development of a nation. Nanosatellites, CubeSats and even smaller Chip-Sats are examples of low cost and lightweight satellites that can be deployed in constellations to improve connectivity and enable satellite edge computing. These small satellites are equipped with powerful processors and have the capability to perform edge computing tasks in space, such as pre-processing data before transmitting it to the ground. The increasing adoption of satellite based IoT services presents opportunities for growth and innovation in this field and on the other hand, software-defined networking (SDN) and network function virtualization (NFV) are two software-related technologies that can enable the efficient management of satellite networks and the deployment of edge computing resources.