What is Satellite IoT Connectivity?

Satellite IoT refers to IoT (Internet of Things) services provided by networks of satellites. IoT enables interconnectivity between objects such that they can communicate and relay orders without requiring human-to-human or even human-to-computer interaction. This allows for hundreds of decisions and actions to be automated based on the data received from remote devices. 

Traditional IoT devices use cellular networks to connect to the internet, however, cellular networks have major limitations in terms of availability in remote locations. An example could be an oil ring in the middle of the sea or a remote location in a dessert or in the mountains. In general, it is estimated that terrestrial networks cover only about 15% of the Earth’s surface and around 50% of the total landmass area. But IoT’s use cases have grown over the years to include rural and remote applications like monitoring of power plants and oil and gas pipelines, Smart Cities, farming operations, point-of-sale locations, security solutions etc. Hence, many businesses are unable to reach remote assets due to insufficient coverage, or prohibitively expensive solutions.

Networking services provided by satellite constellations have become more affordable, available and accessible over the years. IoT services provided by satellites can overcome the limitations of scalability by providing truly global connectivity that can even reach devices with limited or no access to terrestrial networks. Satellites can even provide connectivity over places that have underdeveloped infrastructure or none at all like vast seas and oceans, mountainous regions, remote areas with harsh environmental conditions etc. 

Satellite IoT’s scalability advantage is useful in a variety of scenarios:

• Monitoring and management of containers and goods transported via ships traveling over oceans and seas or trucks traveling through mountain terrains, remote areas etc.
• Scientific equipment and recording instruments deployed in terrains inaccessible to humans such as active volcanic vents, buoys floating on seas, weather balloons etc. can relay recorded data and information to research base stations via using satellite IoT.
• Mining and agricultural equipment have begun to be automated to increase efficiency, production, save time and increase safety. These large-sized robotic pieces of equipment can be controlled from a control room located far away from the actual site of mining and agricultural activity. These industrial activities usually take place in remote locations far away from human settlements with minimal terrestrial network coverage and hence can only be accessed via satellite connectivity.
• Long pipeline networks for transporting water, fuel gases, waste disposal etc. can stretch over hundreds of miles which makes it very difficult to deploy personnel for monitoring and management in dangerous environments over a large area. The thousands of electronic valves, monitoring equipment etc. of a pipeline network can be controlled via satellite IoT-powered devices.

Advantages of satellite IoT:

• Satellite IoT is useful in areas where other internet options are not available or not feasible.
• Satellite connections are wireless which eliminates the need for wired connectivity such as phone lines, a DSL line or coaxial etc. and reduces the number of raw materials needed for network expansion.
• Satellites provide secured communication by using encryption units at hub stations and user terminals. Since a satellite IoT network is generally offered as a proprietary, closed system, it enhances reliability and offers greater security.

Limitations of Satellite IoT:

• There is a delay of about 120 -240 ms when relaying signals from the earth’s surface to satellites and vice versa. This poor latency may affect some applications of satellite IoT. 
• Troubleshooting any system failures or hardware faults that may appear in satellite networks is very difficult compared to cellular networks. Repairs and maintenance for satellite IoT require advanced knowledge of satellite and VSAT technologies.
• Satellites connectivity may be affected by bad weather conditions such as rain, thunderstorm, hailstorm, blizzard etc. which reduces the quality of connection, increase latency etc.
• Satellite signals can get attenuated due to obstructions (tree branches, buildings) in the path of signal transmission. This is a major concern for applications in urban areas with a large number of tall buildings and dense forest areas.  
• Satellite connectivity is still a scarce resource compared to terrestrial networks and hence bandwidth per user may be limited and is usually assigned based on plans. This makes satellite internet more expensive compared to other options and only viable when other types of connectivity are not available.

Due to these disadvantages, satellite IoT is being developed to complement cellular IoT rather than replace terrestrial IoT networks completely. The latest standards and configurations of both satellite and cellular connectivity allow the formation of combined hybrid networks to take advantage of the best features of both network types and maximize global connectivity. It is currently used where terrestrial networks are not available or can not be set up.

Incumbent satellite providers have their satellites already up in space and their investments in the space and ground segments have already made. Traditional Mobile Sat Systems (MSS) like Inmarsat, Thuraya, Iridium, Globalstar etc. have been dominant in the M2M/IoT market, using their L-band spectrum with a focus on mobile and maritime applications. Fixed Sat Systems (FSS) like Eutelsat, Intelsat or Asiasat have developed M2M and IoT services using the Ku-band or Ka-band over the past years as well.  Examples are the Ka-sat based Telemetry service from TooWay/Eutelsat, and the development of the ASAT-8200 unit by Spacebridge. With their higher bandwidths, they are very well suited for Satellite IoT and in particular for backhaul services connecting terrestrial local area IoT networks (eg. NB-IoT, Lora, Wifi, BT) from high-density sensor networks to the internet.

The NewSpace industry, which refers to the newly emerged private spaceflight industry and several nanosatellite IoT startups, take advantage of the new CubeSat technology (using a range of UHF, VHF, S-band, and Ku-band services) to bring down their service costs to take advantage of the lucrative satellite IoT market. These CubeSats are Low Earth Orbit satellites that allow the use of low-power modems to connect the ground sensors. NewSpace companies active in this market include Astrocast, Myrioata, Lacuna, Kineis, Kepler Communications, Swarm technologies, Hiber etc. Their service features, low cost, low power and low latency make them well suited for Direct-To-Satellite services for IoT devices that are spread widely over geographic areas.