LEO satellite connectivity for IoT
Satellites in LEO, which orbit closest to the Earth, move quickly and take only 90 minutes to circle the planet. They are much smaller than MEO and GEO satellites and provide coverage to a relatively small area of the planet’s surface as they travel overhead. Three ways are commonly used to maximize coverage for LEO satellites.
Some satellite operators, such as Iridium, create a mesh network to ensure reliable connectivity. Satellites within a mesh network can communicate with one another, passing data from one satellite to another until the final destination is reached. Antennas communicating with a mesh network don’t need to be pointed towards a single satellite, making these networks ideal for mobile IoT applications like weather balloons or data buoys.
Another option is to have fewer satellites but more ground stations, which allows for more bespoke local service provisions such as local network access. This is used by Globalstar and Orbcomm.
Newer entrant satellite operators, such as Swarm, have opted for a relatively large number of very small satellites called cubesats. The sheer quantity of satellites means there is almost always one overhead, so antennas don’t need to be pointed.
Cubesats are also popular for various space missions, including Earth observation, communication, and scientific research. Due to their small size and low cost, cubesats can be relatively inexpensively used to build constellations of satellites for various applications, including satellite IoT connectivity. However, their small size leads to a shorter operational life expectancy, so operators need large numbers of active and failover cubesats to ensure wide-spread and reliable coverage.
MEO (Medium Earth Orbit) satellites orbit the Earth at a higher altitude than LEO (Low Earth Orbit) satellites, usually between 2,000 and 36,000 kilometers. Because they are larger than LEO satellites, MEO satellites can cover more ground and offer more stable connectivity. They are commonly used in aviation and maritime applications, where reliable communication is critical for safety. MEO satellites also offer higher data rates, making them well-suited for IoT applications that require the quick transmission of large amounts of data, such as video surveillance and remote sensing.
However, MEO satellites have a longer round-trip time, which can result in higher latency, and they are more expensive to launch and maintain than LEO satellites. This can make them less accessible for smaller IoT applications. SES and Galileo are examples of network operators that use MEO satellites.
Geostationary satellite connectivity involves satellites positioned at a fixed spot above the Earth’s equator, around 36,000 kilometers away from the surface. This type of connectivity is ideal for applications requiring high bandwidth and consistent signal coverage, such as video streaming, remote surgery, and aviation communications. Each geostationary satellite can cover almost a third of the Earth’s surface, making it perfect for providing connectivity in remote or hard-to-reach areas. Because the satellite is stationary, it can provide a constant link between the IoT device and the ground station.
However, the high altitude of geostationary satellites results in higher latency of about 700 milliseconds (compared to 50 milliseconds for LEO satellites), which can affect certain applications that require real-time responses. Also, because there are only a limited number of geostationary orbital slots available, the cost of launching a new satellite and securing a slot can be prohibitively expensive.
Despite these limitations, geostationary satellite connectivity remains a valuable option for IoT applications that require high bandwidth and wide coverage. Inmarsat, Intelsat, and Eutelsat are examples of network operators that use geostationary satellites.
Choosing the right type of satellite IoT
Selecting the appropriate type of satellite IoT entails considering numerous factors. At Ground Control, we typically guide our clients through a series of questions to help them narrow down their choices, including:
- How much data does your application consume?
- How time-sensitive is the data you receive?
- Where are your assets situated?
- Are your assets stationary or in motion?
- What degree of data security do you need?
While this isn’t an exhaustive list, it should provide a good starting point for initial research.
We understand that navigating the world of satellite IoT can be challenging, which is why our team of experts is always available to answer your inquiries and help you pick the right solution for your company. Please contact us at email@example.com today to learn more about how we can assist you in connecting from anywhere in the world.