5G and LEO Satellites
- [Satellite - NASA]
- Overview
5G has arrived, and new equipment is currently being installed in densely populated cities across the globe. In many cases, the demand for 5G capacity is exceeding infrastructure improvements, especially in sparsely populated areas that are difficult to access. For years, satellite communication has remained standalone technology, independent of mobile networking. Now with the next generation of satellites – built from 5G architecture – they will integrate with networks to manage connectivity to cars, vessels, airplanes and other IoT devices in remote and rural areas.
A series of plans with broad market prospects have therefore been developed. The plans are mainly based on low-orbit micro-satellite constellations, with great advantages in terms of functional density, development cost, launch difficulty, etc.. These constellations can effectively solve the practical problem of networking in remote areas, such as oceans and deserts, and they have irreplaceable advantages in emergency communications, disaster warnings, and maritime rescue.
In the near future, 5G signals will beam down from space and support our ‘terrestrial’ 5G infrastructure on Earth. The end result is a new space race for satellites – promising to offer customers a seamless wireless experience across the entire globe.
- Low Earth Orbit (LEO) Satellites
A low earth orbit (LEO) satellite is an object, generally a piece of electronic equipment, that circles around the earth at lower altitudes than geosynchronous satellites. LEO satellites orbit between 2,000 and 200 kilometers above the earth. Demands from 5G means cheaper low earth orbit (LEO) satellites are needed to perform multiple satcomms functions. The aim for these is simple in concept: To revolutionize accessibility to space and at a low cost, and with super-fast speeds.
This question of latency is key. Some geostationary satellites at 35,786 km already provide broadband services but their transmissions take about 500-700 milliseconds (ms) to travel up and another 500-700 milliseconds to travel down. This time-lag is why viewers suffer the infuriating time delay during a conversation between the broadcast studio and an outside broadcast unit. If the OB (Outside broadcasting) is more than one satellite ‘hop’ away, then the delay is multiplied. A low Earth-orbiting craft would manage these links in about 25-30 ms, a true fraction of existing satellite links and quite comparable to existing cable or fibre networks.
The need for ubiquitous coverage for many of the proposed 5G use cases – in particular the Connected Car – has necessitated a plan to include other connectivity solutions such as Wi-Fi and satellite communications in future hybrid networks, in order to ensure that there will be no holes in the 5G coverage map.
- Low-Orbit Revolution
In the next decade, space will be an important battlefield for the development of next-generation global wireless communication technologies (B5G/6G NTN non-terrestrial network systems). In ten years, there is expected to be more than 60,000 LEO satellites flying at a speed of 7km/s to provide global wireless communication services.
Although satellites can deliver virtually blanket coverage, and potentially also the high data rates demanded for 5G, they do have a disadvantage in terms of latency. Due to the long distances involved, latency for an LEO is typically 30ms – better than the 40ms that is typically achieved by 4G LTE, but poor compared with the 5G target of less than 1ms.
Traditional communication satellites are geostationary and have been in orbit for more than 50 years. GEO satellites weigh more than 1000kg and operate 36,000 kilometers above the earth. These satellites remain in a fixed position relative to any position. Despite Earth’s orbit, this allows ground-based antennas the ability to point directly at the satellite, in a fixed position. In contrast, Low Earth Orbit (LEO) satellites are miniaturized, orbiting versions that operate between 500 and 2000 kilometers above Earth’s surface and weigh under 500kg. Due to its low orbit, latency is significantly reduced as the satellite is better positioned to quickly receive and transmit data. Unfortunately, this also creates a smaller coverage area so LEO satellites continuously hand off communication signals and traffic across a constellation of satellites. This ensures seamless, wide-scale coverage over a pre-defined geographical area.
- Private LEO Satellites
LEO satellites are the new space race. The new space race is emerging among tech companies (SpaceX, Amazon, OneWeb, etc.) to deploy LEO satellite constellations to deliver high-speed Internet service to emerging markets and business customers. Each of these companies recognizes the potential of private satellite constellations to not only provide Internet connectivity to rural areas but satisfy the global networking services of tomorrow.
Eventually, Elon Musk (Starlink) will deploy 40,000 satellites. Greg Wyler (OneWeb) will deploy 2,872 satellites, and Jeff Bezos (Project Kuiper) will deploy 3,236 satellites.
[More to come ...]
