Introduction to IoT

Satellite

As the name implies, this form of connectivity uses satellites to connect sensors/devices to the cloud. The first artificial communications satellite was launched in 1960, and served merely as a giant reflector for signals beaming between different places on the earth’s surface. Today’s communications satellites are much more robust and featured.

The importance of satellite connectivity for the Internet of Things comes from its incredible coverage. A single network of satellites is capable of providing coverage to effectively the entire planet. This means that a single device moving around the world can stay on a single network and use only a single connectivity type.

Satellite’s incredible range give it an advantage in remote areas that other communication types such as cellular or Wi-Fi cannot reach, and in places that have underdeveloped infrastructure or none at all, such as the middle of the ocean.

Satellite connectivity has two major configurations with respect to connectivity: direct and backhaul.

Direct

The first major type of configuration, direct, is broken down into the two sub-categories: dual mode and satellite only.

Dual mode satellite connectivity is connectivity that uses cellular data as much as possible and uses satellite when necessary. This gives a best-of-both-worlds connectivity option that leverages the lower cost and higher bandwidth of cellular when possible, but makes use of satellite connectivity’s greater coverage to fill in spaces where cellular data connections are sparse or unreliable.

The best example of this connectivity is container ships, which use cellular when in port or near coastlines, but make use of satellite when on the open ocean.

Satellite-only connectivity is exactly what is sounds like, a data connection that uses purely satellite connectivity to transmit data. This is typically for large, immobile resources like oil and gas equipment, that are sending large amounts of data from locations that have no cellular or other connectivity options.

Backhaul

The second major type of configuration, backhaul, uses a main tower that connects directly to a satellite and then a different kind of connectivity (e.g. an LPWAN) to connect with the sensors/devices in the area. This connectivity option is typically used when you have many low bandwidth sensors/devices in remote areas.

Satellite requires high power usage, and can require larger pieces of equipment such as dishes for connectivity. This raises the cost for individual sensors/devices, and can make direct connection infeasible for groups of sensors/devices that don’t use much data.

One example of this is a farm that uses a set of moisture sensors to collect soil data. All of those sensors may use an LPWAN to connect to a main tower that then transmit the data over a satellite connection. This saves on battery life and lowers the overall cost of the sensors.

Key Takeaways

Satellite has excellent coverage, but with it comes larger equipment and higher battery usage than other connectivity options. Satellite also has good bandwidth, but can be expensive at scale. As such it fills a niche where a single tower can be used to service a group of sensors/devices, sensors/devices are larger and higher costs are acceptable, or sensors/devices are so remote that satellite is the only means of transmitting data to the cloud.

In these instances, satellite is an excellent connectivity option because a single network can encompass the entire globe, and connectivity can be reliable in places no other options can reach, even in the middle of the ocean.

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