Designing Low Earth Orbit (LEO) Satellites for Global Connectivity

Today, users can connect to the internet in the following ways:

• Terrestrial, Wired Connections 

Today, most people access the internet via a coaxial cable or fiber-optic line that connects directly to a modem/wireless router in their home or office. That wire is physically connected to a vast network of cables that link back to the internet service provider and ultimately to the internet. Wired connections require a significant investment in materials and internet infrastructure that might not be an option for developing countries, hostile environments or areas separated by treacherous terrain. Terrestrial systems are also vulnerable to disruption. Simply cut the cable and the connection is lost.

• Cell Towers

Cell phones provide a relatively reliable internet connection. Your phone is  connected to a cell tower using a radio frequency (RF) signal, which degrades over distance and can be overwhelmed by heavy traffic. For example, you’re at a crowded football game with a full-strength signal, but you can’t make a phone call or connect to the internet because thousands of people in the area are trying to connect at the same time.

• Satellites
  

Satellites with Medium Earth Orbits (1,243 to 22,236 miles above sea level) and High Earth Orbits (more than 22,236 miles above sea level) are used to deliver information, services and content. However, the lag time (latency) increases the farther the satellite is from Earth. As a result, these types of satellites are best suited to one-way transmission such as sending television or radio signals or delivering streaming services. For example, when watching a streaming television service, it’s tolerable to wait a few seconds for a video to buffer before you get a constant signal. 

LEO satellites provide the best solution for connecting remote, hostile or rural areas to the internet when traditional terrestrial or cell-based internet connections aren’t an option. LEO is defined as fewer than 500 miles from the surface of the earth, though most LEO satellites are positioned approximately 250 miles above the earth. There are three key advantages to using satellites that are closer to the earth’s surface:

• Real-Time Conversations

Latency refers to the time it takes for a signal to be sent and returned. Therefore, the closer you are to the satellite, the shorter the delay between signal and response. LEO satellites allow for two-way communication in real time.

• Reliable Connections

Unlike a physical connection that can be severed or a cell tower that can be overwhelmed or disabled, a satellite connection is typically more difficult to disrupt. This means users can more reliably count on sending and receiving critical information.

• Cost Savings

Compared to Medium or High Earth Orbit options, LEO satellites require less energy to be put into orbit and rely on less powerful amplifiers for transmission to and from Earth. As a result, LEO-based networks are generally less costly than options that require satellites with higher orbits.

The relatively low orbit of an LEO satellite reduces its coverage area, so multiple satellites are required to bring internet connectivity to a region.  This network of linked LEO satellites enables global coverage. Two technologies are critical to making low orbit satellite internet possible:

• Active Electronically Steered Array (AESA) Antennae

An AESA antenna uses RF technology to point a beam of radio waves in different directions without moving the antenna. This is a tremendous improvement over conventional antennae that rely on a complex mechanical system, called a gimbal, that is used to maintain the connection between the user and the satellite network.

• Optical Laser Technology

LEO satellites use lasers to connect to one another at the speed of light. Lasers are ideal for this purpose because there is very little in space that can interrupt the signal. What’s more, unlike RF transmissions, optical lasers cannot be intercepted or jammed. Most attempts to interrupt the signal will be detected and thwarted immediately.

Whether it’s for a rural area cut off from the internet after a hurricane or a remote part of a national park that’s miles from the nearest cell tower, LEO satellites can bring life-changing benefits of an internet connection to communities that have been difficult to access until now:

•   Education

Access a wealth of educational materials, resources and online teaching platforms. Better-connected students can learn beyond the walls of their school and interact with students in other parts of the world. 

• Health Care
  

Connect to quality health care virtually anywhere. Doctors can chat with patients online and see the patient’s condition using video calling applications.

• Safety

Reach out for help when cell service is not available. Hikers who get lost or injured in a remote area can connect to emergency rescue services.

• Financial Services

Send and receive money online. Safely connect with a bank remotely when it may not be safe to visit the bank in person. Invest in opportunities that aren’t available without an internet connection.

• Entertainment

Watch movies, listen to music or watch a child’s sporting event when it’s not
possible to be there in person.

Delivering global internet access is a monumental task that will generate a tremendous amount of data. TE Connectivity offers the high-speed connectors, ruggedized fiber-optic solutions, interconnects, backplane connectors, sensor technology, and wire and cable that connect the subsystems on LEO satellites and in ground stations to keep the flow of data moving as quickly and efficiently as possible. Our portfolio of products can also withstand the harsh environments in space and on the ground.

As countries and companies rush to invest in LEO connectivity programs, TE is positioned to deliver the critical components needed to build these virtual highways around the world.

• Wired connections, cell towers and satellites are used to provide internet
  connectivity to most users; however, each of these options has limitations that make it impractical or impossible to use in remote locations or hostile environments.

• Low Earth Orbit satellites provide the best solution for global connectivity to the internet

• LEO satellites reduce latency to enable real-time conversations while offering connections that are more difficult to disrupt.

• Active Electronically Steered Array (AESA) antennae and optical laser technology make LEO satellites an efficient and effective option for universal satellite internet connectivity.

• LEO satellites can improve the quality of life for residents of remote areas
  by delivering educational opportunities, improved health care, access to
  enhanced financial services and entertainment.