Advantages of Space-IoT

Global coverage. Most of the IoT deployments rely on cellular IoT networks, public and private long-range IoT networks, and WiFi. All of these networks have a limited coverage range. Many of these infrastructures are available in only densely populated areas, but provides scant coverage in rural areas and uninhabited areas. A swarm of interconnected satellites can cover a large area and is almost always available. Satellite-based IoT can be employed in conjunction with terrestrial networks to accomplish true ubiquitous global connectivity covering all the blind spots. A case in point is the disappearance of Malaysian flight MH370.

Reliability. The number of IoT devices is indeed growing unboundedly. As more devices are being added to the IoT ecosystem, there should be a way to ensure that the services are reliable. Especially, in mission-critical IoT applications that include Machine to Machine (M2M) communications, high reliability is a must. Terrestrial wireless communications are usually subject to complex RF propagation phenomena but connecting with the satellite would be usually straightforward. A Swarm of satellites would provide 100% availability.

Scalability. IoT devices are being deployed in huge numbers and scalability regarding connectivity is a difficult proposition. The infrastructure should meet the changing needs in the future. Given the large field of view of a satellite, several thousands of nodes can communicate at once, which can be supported by a single satellite.

Connectivity. Similar to scalability, continuous and steady availability of the communication system is crucial to many IoT applications, especially in applications having mobile devices. Examples include a fleet of vehicles, marine communication, logistics and asset tracking.

Data bandwidth. Satellite communication technologies are advancing rapidly. Starlink constellation is promising up to 10Tbps of throughput. Enabling direct sensor–satellite communication or sensor–gateway–satellite path can provide high throughput, low latency and a scalable network.

5G and IoT. The mobile industry is ushering in the 5G communications era. New standards are being inalized in 5G to optimize communication technology in many ways. Satellites are already a part of the 5G network for wireless communication. Furthermore, satellite networks have already demonstrated their exceptional abilities in Software-Defined Networking (SDN), edge computing, and in various scenarios where a lot of bandwidth, optimal speed and performance, and low latency are required. As a result of these advantages, Space-IoT is a boon for 5G communication.

Space exploration. Space-IoT paves a way for advanced space explorations that include space robots, planetary missions, satellite swarms forming radio telescopes, and space colonization. The strategy of execution of space systems, such as the Moon habitat, includes hundreds of connected sensors and actuators, and a swarm of Artificial Intelligence (AI) based robots assisting the astronauts. In such cases, the reliability and availability of these devices all the time are crucial. Space-IoT can meet the requirements of such space explorations.

Applications of Space-IoT

We briefly touch upon some of the important applications here.

Emergency services: Emergency services are mission-critical and the network must be available all the time. Examples of emergency services include disaster management, military data transmissions, and satellite phone systems. These applications cannot afford any interruption in the network. Especially, during natural calamities, such as floods, and cyclones, the terrestrial communication infrastructures are directly affected. Satellites are immune to these problems. Hence, Space-IoT is preferred for emergency service-based IoTs when the terrestrial network is either inaccessible or reliable.

Maritime applications: Space-IoT offers thriving solutions when it comes to maritime applications. Satellites deliver uninterrupted and endless service even on seas and oceans that are far from terrestrial network coverage. This is advantageous for services such as fisherman tracking and warning systems, marine logistics and vessel tracking, emergency communication services for the navy, and satellite-based networking for offshore oil and gas industries.

Smart agriculture: Modern smart agriculture includes numerous IoT sensors to monitor crop health, temperature, soil, humidity, etc., to enhance crop quality and increase yield. The data from these sensors are collected by a gateway and then communicated to a cellular tower. In most countries, agricultural lands are far away from the cities due to the unavailability of vast land suitable for agriculture in densely populated locations. Such areas may not be in proximity to cellular networks. For such areas, Space-IoT can be a prominent asset. Satellites can communicate with numerous agricultural IoT sensors directly or via a gateway and facilitate precision farming to make accurate data-driven decisions. Many companies are investigating the potential of Space-IoT in smart agriculture.

Healthcare: Healthcare is given the utmost importance in any country. The researches in this field are incessant and Space-IoT can contribute to healthcare in various aspects. Examples include (i) satellite communication-based IoT devices mounted beside streets that can detect accidents in isolated areas and call for emergency help, (ii) remote health monitoring of patients before they arrive in the hospitals under critical conditions, especially when terrestrial networks fall short. Satellites can navigate and track ambulance drones equipped with lifesaving technologies such as Automated External Defibrillator (AED), medication, and Cardiopulmonary Resuscitation (CPR) aids.

Connected vehicles: Connected vehicular technology is getting more popular. The future of mobility is automated and connected. To prove safety at high levels of automation, reliability is the key. A robust and redundant connection from the vehicle to the digital infrastructure is required and must be available everywhere. Satellites and terrestrial Services can integrate with 5G to provide this connectivity.

Challenges for Realizing Space-IoT

The figure above provides a sneak-peak into the challenges in realizing small satellite constellations in the context of Space-IoT.

Miniaturization. Access to space has always been expensive as enormous efforts and resources are required to launch a satellite. It takes around $20,000 to place 1kg of payload (satellite) in orbit at an altitude of around 500 km. Extrapolating this cost linearly, even a small satellite of 10kg would cost $200,000 just for the launch. Considering these numbers, one can imagine the time and cost that would take to construct a mega constellation of hundreds or thousands of satellites orbiting the earth and working as one system. Therefore, the miniaturization of satellites takes prime importance to reduce space mission costs.

Energy management. As aforementioned, when a satellite is miniaturized, its solar cells may get reduced in size and count. This causes a shortage in generated power. Through miniaturization, even though, we reduce the overall power of the space system, some cannot be reduced, for example, transmission power. The maximum harvested power is reduced but transmission power would remain the same. This imposes severe requirements on both the energy consumption of individual modules and run-time distribution of available power.

Communication. Relaying data to the ground and exchanging information among the satellites in a constellation are functional requirements of Space-IoT. This is a difficult proposition for small satellites. Thus a reliable, low-power communication technology needs to be evolved – ranging from RF to optical communications. Considering the Space-IoT applications, when there is a large number of IoT devices that need to be connected, a high data rate is required. This can only be achieved by allocating a large amount of energy, which is scarce. New RF technology and large antennas potentially ameliorate these issues but their sizes are limited by the satellite’s physical structures. Another critical challenge that needs to be considered in satellite communication is the Doppler effect. Most satellites move faster than a bullet. Thus achieving a good link budget is difficult..

Resilience. Satellites are bound to operate in harsh space environments, with temperatures varying from -100°C to 150°C and cosmic radiations harming elementary data operations, such as memory reads/writes, causing transient faults. Large satellites are designed to be highly dependable, using expensive thermal protections, radiation-hardened space-grade components, and highly reliable storage hardware, such as Error Coding and Correction memories. Small satellites are usually built using COTS components to reduce costs, which provide nowhere near the same or similar dependability guarantees. This is a huge challenge.

Coordination. If swarms need to be built, then coordination between the satellites is required which in turn needs accurate positioning of the satellites. Considering the speed of the small satellites in LEO, this is atremendous challenge.  Global Positioning Service (GPS) based localization is the most commonly used positioning technique in space but it requires high power for the reception of the signals and computation. A good positioning/localization module is a difficult proposition.

There are many challenges and the above list is only the tip of the iceberg. In the near future,  billions of IoT devices will be deployed and we need to be prepared to connect them to the Internet. Space-IoT is a game-changer for the future of IoT, and it opens a world of new possibilities by providing global network coverage, scalability, and connectivity. The future of IoT looks promising with space infusion. We believe that space is largely an unconquered frontier where even the sky is not the limit – literally and figuratively.

We refer interested readers to the following works, on which we have based this blog article.

References

1. S. Narayana, R. Muralishankar, R. Venkatesha Prasad, and V. Rao, “Recovering bits from thin air: demodulation of bandpass sampled noisy signals for Space-IoT”, In Proceedings of the 18th International Conference on Information Processing in Sensor Networks (IPSN ’19), pp. 1–12, 2019.
2. S. Narayana, R. Venkatesha Prasad, V. Rao, and Chris Verhoeven, “SWANS: Sensor Wireless Actuator Network in Space”, In Proceedings of the 15th ACM Conference on Embedded Network Sensor Systems (SenSys ’17), art. 23, pp. 1-6, 2017.
3. S. Narayana, R. Venkatesha Prasad, V. Rao, L. Mottola, and T. V. Prabhakar, “Hummingbird: energy efficient GPS receiver for small satellites”, In Proceedings of the 26th Annual International Conference on Mobile Computing and Networking (MobiCom), art. 9, pp. 1–13 2020.
4. S. Narayana, R. Venkatesha Prasad, and T. V. Prabhakar, “SOS: Isolated Health Monitoring system to Save Our Satellites”, In Proceedings of the 19th Annual International Conference on Mobile Systems, Applications, and Services (MobiSys ’21), pp. 283–295, 2021.
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9. https://www.researchgate.net/publication/356802601_Internet_of_Things_in_Space_A_Review_of_Opportunities_and_Challenges_from_Satellite-Aided_Computing_to_Digitally-Enhanced_Space_Living
10. https://www.perle.com/articles/space-related-iot-projects-that-will-surprise-you-40192914.shtml
11. Internet of space things extending iot applications in space  https://iotmktg.com/internet-of-space-things-extending-iot-applications-in-space/