We have seen a fair number of headlines on Starlink and the new generation of mobile phones from Apple and Huawei with satellite links. How do these work?

Starlink is the first satellite broadband product that has become consumer. Some of us may have used internet connections on flights or on a cruise. These use satellites that hang directly over us all the time, at 35,786 km to be precise. These are called geostationary satellites (GEO). The terminal receivers are quite large and require some specialised expertise to operate.

Starlink uses a new technology called Low Earth Orbit (LEO) satellites that fly above us at only 500 to 1,200km. Their low orbit means less power is needed send data from the terminal to satellite and vice versa. These antennas are also smart and electronically steered unlike those from Singtel that you see along the BKE. Here’s a short video from Starlink’s competitor OneWeb: https://www.youtube.com/watch?v=REzA_SYInvc

The low earth orbit also means the delay is in tens of milliseconds compared to GEO which can take more than 0.5 seconds to make a round trip. So, you can have videoconf or play games using LEO, but not on GEO.

The power is so low that you can actually communicate via these satellites using a handphone. Apple and Huawei are using LEO satellites for their latest emergency services. https://www.youtube.com/watch?v=Dx1Wn7JpObM Good if you’re lost at sea or in a desert somewhere. But the amount of data you can send continuously from handphones is still limited. Your battery will deplete quickly, and your ears may get hot if the bit rate is increased. Furthermore, you’ll need to point the phone towards one of the many LEO satellites that zip overhead to send your message or simple photo.

The same technology is also used in Internet-of-Things applications with small independent satellites, some even launched by universities (cubesats), because small satellites has become so cheap to launch these days. Here’s a short video on using LPWAN and LEO for IoT communications from a vendor: https://www.youtube.com/watch?v=4G2d3ek7PTQ

If you would like to learn more about LEO satellites or 5G or other wireless communications, please see our DreamCatcher courses below:

Introduction to Low Earth Orbit (LEO) Satellite Technology (CT3058) https://dreamcatcher.asia/training/3058
Overview of Wireless Technologies (RF39) https://dreamcatcher.asia/training/39
5G Technology (CT1509) https://dreamcatcher.asia/training/1509
Using 5G in Internet of Things End-to-End Application Designs (CT2336) https://dreamcatcher.asia/training/2336