In 1957 the first artificial satellite was launched, and since then thousands of satellites have been put into orbit. This capital-intense industry has expanded its domain and moved from being solely government-funded to being financed by an array of investors, from visionary billionaires to angel investors.
The interest in space has expanded beyond the military realm and state monopolies, towards the creation of a New Space economy. This economy relies increasingly on the private sector and on the commercialization of space. This comprises the provision of telecommunication services, the construction, and operation of rockets and satellites, the processing of data, human space flights, and even the creation of a sustainable presence on the Moon, with people living and working in space.
Within the telecommunications field – the main focus of this paper – satellites have been used to gather information relating to the characteristics of the Earth and its natural phenomena, for meteorological purposes, for radio-location purposes, for broadcasting (television), for the provision of backhaul and broadband connections (Internet), and more recently, to connect a myriad of objects (the Internet of Things).
The first satellites launched were geostationary orbit (GEO) satellites, located 36,000 km above Earth’s equator. These satellites remain on their circular orbit and follow the rotation of the Earth very accurately, allowing the ground antenna to be pointed permanently at the position in the sky where the satellites are located. The capacity (bandwidth) of these satellites has evolved considerably with the use of spot beams and high frequency bands, such as Ku and Ka bands (above 12 GHz and 27 GHz respectively), ideal for broadcasting and broadband.
In spite of these advantages, the services provided by GEO satellites are limited by the latency of the network and the cost of the connection. The latency cannot be reduced beyond the time required for the signal to travel from the ground to the satellite and back (at the speed of light), and the manufacturing and launching costs of these satellites are considerable. Located above the equator, GEO satellites are also not optimized to connect assets in high and low latitudes.
To overcome these challenges, medium orbit satellites at 8,000 km from the Earth were launched. [FJ1], and more recently, Low Earth Orbit (LEO) microsatellites and nanosatellites were launched at low orbits of around 1,000 km and below.
The proximity of the Earth is especially appealing. On the demand side, it enables low power devices, low latency, and zenith pointing at all latitudes, including the poles. On the supply side, the small size of the satellites drastically reduces the cost to produce and launch a network and consequently results in the provision of more affordable satellite services.
Thus, new satellite constellations are being launched (or plan to be launched). Some companies have focused on the provision of broadband connection to the 49% of the world’s population that remains unconnected to the Internet. Others aim to connect billions of devices to the Internet of Things (IoT). This is the case with Astrocast.
Its IoT network aims to provide a high connection density, network energy efficiency, and low latency. What’s more, by using the L-Band frequency, Astrocast supports the use of devices with small antennas, ideal for several IoT applications.
Currently, connectivity of IoT devices can be established by using terrestrial technologies, such as WiFi, LoraWan, Sigfox, and mobile technologies (2G, 3G, 4G, and soon 5G).
The advantage of satellite networks is that once deployed, they can cover entire countries, connecting the most remote and rural areas, the sea, the air, reaching regions where no other terrestrial communications are available. This enables communication on islands, on agricultural areas, on roads, ships, and planes, bringing together thousands of devices into a single network. Moreover, satellites are crucial for critical communications where terrestrial networks are not available or have been disrupted.
Astrocast is a key player in the satellite IoT communications market. It is leveraging the benefits of the deployment of a nanosatellite LEO network using the L-Band frequency to provide global connectivity for IoT devices spread around the world.