The new Viasat satellites will each have a capacity of 1,000 gigabits per second


Credit: Viasat

In the world of communications, one gigabit is a lot. Data is measured in bytes, and a gigabit is roughly equal to one billion bytes.

Times the gigabit by one thousand and you’ll have the capacity per second of the next satellite that Viasat will be launching. And the company is planning on launching three, each one costing just over half a billion dollars.

The three Viasat satellites will all use the Ka-band. In satellite communications there are two different bands that are used, Ka-band and Ku band. Put simply, the main difference between Ka and Ku is the frequency bands that are used.

Ka-band uses the 30GHz uplink & 20GHz downlink frequency range, whilst Ku band uses 14GHz uplink and 12GHz downlink frequencies. A higher frequency range is better, as the signal degrades at a much slower rate, making the connection more stable. Ka-band also has a lower wavelength, although this is obviously inversely proportional to frequency of the wave.

The first of the new Viasat satellites will launch service in 2020 and, by the time that the third one launches, Viasat will have complete global coverage. It will also have a much higher gigabit per second capacity than any of its competition.

“Each one of these satellites will have more capacity than every other communications satellite in orbit today. That’s how big they are. They are measured in gigabits per second of capacity, and each of these satellites has 1,000 gigabits per second capacity. Our competitors’ Ka-band has 7 gigbits per second of capacity.” says James Person, Viasat’s global director of business development.

During the EBACE show, Embraer announced that it had chosen Viasat to provide the internet connectivity on its Legacy 450 and Legacy 500 aircraft, marking the first time that Ka band connectivity will be pre-installed in medium-sized business jets.

The first aircraft to be delivered with the Ka-band system will be handed over to its new owner in the second quarter of 2019, although current Legacy 450 and Legacy 500 owners will soon be able to retrofit their aircraft with a kit.

Viasat can do this thanks to a very small onboard system that only includes three line-replaceable units (LRUs), which is fewer than the company’s competitors.

In a large-cabin aircraft, the first of these is installed the radome in the aircraft tail. This is the antenna and antenna control unit (ACU), which is powered by the antenna power supply, which is usually installed in the rear of the aircraft. From here, a modem sits in the aircraft cabin.

For smaller aircraft, Viasat designed its LRUs to be to be fitted outside the pressurised shell of the aircraft cabin in the electronics bay.

With larger aircraft, Viasat can install both Ka and Ku band antennas. The company originally did this thinking that customers would want both bands to ensure uninterrupted coverage, but soon found that executives wanted both bands for back-up and redundancy.

“They never want to be without coverage,” says person, “It used to be that if an engine is on fire, that’s an AOG (Aircraft on Ground). Now if it’s the internet not working, that’s AOG. And, so, this way they will never be without internet.”

Alongside business aviation, the company also supplies internet connectivity to airlines, yachts, and home installations.

But perhaps the most interesting application outside business aviation is with Community WiFi, a project to help remote communities gain access to the internet.

So far, the company has helped over 200,000 people in 450 locations across Mexico get online through the project, part of the company’s mission to be the world’s first truly global internet service provider.