c. 2013, when Bailey Brooks, a six-year old School of the Air student who lives on a cattle station 400 kilometres (250 mi) from Alice Springs, won a competition to draw a picture of how a satellite could benefit rural Australians, little did she know that her drawing of a rocket would later be printed on the payload fairing of what she and her classmates dubbed the “Sky Muster" satellite. Aptly named, as it would soon bring remote Australians together as tightly as a cattle muster.
Today, the Sky Muster™ satellite service is delivering the nbn™ broadband access network to homes and businesses in regional and remote Australia, via two state-of-the-art satellites. So, people across mainland Australia and Tasmania, and remote islands such as Norfolk Island, Christmas Island, Lord Howe Island and the Cocos (Keeling) Islands can now enjoy nbn™ powered plans through Sky Muster™ satellite providers.
But in c.2013, the idea to provide extensive broadband coverage to this vast region was far from a fully developed plan. While there were certainly many factors in the program’s success, one key space communications system factor was finding a low noise amplifier (LNA) that offered the critical frequency and noise performance characteristics they needed. (The Earth to the satellite communications are being transmitted at 27 GHz to 31 GHz, while the satellite to the Earth communications are being transmitted at 17.7 GHz to 22 GHz.) They chose Custom MMIC’s CMD 162 LNA MMIC for its inherent performance and the ability to be fully-qualified for space in a hurry.
The CMD162 is a highly efficient GaAs MMIC low noise amplifier (LNA) originally designed for EW and communications systems where small size and low power consumption are critical design requirements. The device was attractive for the Sky Muster design team’s transmit and receive integrated assembly (TRIA) because it was optimized for 30 GHz and delivers greater than 22 dB of gain with a corresponding output 1 dB compression point of +7 dBm, and a low noise figure of 1.7 dB. The CMD162 LNA MMIC is also a 50-ohm matched design, which helped the TRIA engineering team eliminate the need for external DC blocks and RF port matching. The CMD162 amplifier also offered them full passivation for increased reliability and moisture protection. It was the perfect alternative to much higher cost and more difficult to space-qualify hybrid amplifiers.
Here’s 8 interesting facts courtesy of Hannah Francis of the Sydney Morning Herald.
Not just in physical size; although Sky Muster has that in spades at 26 metres long, 12 metres wide, 9 metres tall and a whopping 6400 kilograms, making it one of the world's largest communications satellites. The entire LTSS project aims to deliver broadband to 240,000-odd remote and rural Australians from Christmas Island to Macquarie Island, making it "easily one of the largest satellite projects in the world", according to Gavin Williams, executive general manager new developments, wireless and satellite at NBN.
Sky Muster will hover in geostationary orbit above Australia, meaning they will follow [them] in unison with the Earth's turn to deliver consistent service. Sky Muster is positioned 140 degrees east longitude, while the second satellite will be at 145 degrees. This is in contrast to the IPSTAR satellite which currently provides the interim satellite service to rural Australia; it sits at 120 degrees east.
The LTSS satellites are designed with a life span of around 16 years. That's not because their structure or materials will break down, but because they will eventually run out of fuel. The satellites stay in the right spot above Australia by emitting gentle thrusts to keep them on course. They don't need much fuel at all because in space there's no resistance – that's why it can last them as long as 16 years.
The LTSS shoots 101 "spot beams" across Australia. Each one of these contains a limited amount of bandwidth, but there are some overlaps, so some customers might fall under more than one beam. That doesn't mean they can siphon more bandwidth though. When users connect to the service, NBN will allocate them to one beam only, and to one of the two satellites only, depending on what is best for sharing the load across the entire network. If one beam on one satellite happens to get congested – though Williams says NBN is "confident" that won't happen as more than enough room has been allocated – NBN can seamlessly switch customers to another beam or satellite.
NBN has specially designed household satellite dishes at 80cm in diameter, which it says will service 94 per cent of LTSS customers. The remainder might need bigger 1.2 metre dishes – the kind currently being used for the NBN's interim satellite service. Williams says the dishes were designed with easy installation in mind, with individual LTSS installation teams aiming to average two satellite installations each day – a couple of hours per installation, plus travel time.
A big factor in ease of installation comes in the form of a little accessory called a transmit and receive integrated assembly (TRIA). It's basically a tuner attached to the dish. Once the dish is on a roof, the TRIA gives feedback via a series of beeps to let the installer know where to position the dish to receive the strongest signal from Sky Muster.
The satellite broadband connection at the testing facility in Brunswick recorded download speeds of around 25Mbps and upload speeds of around 4Mbps*. That's about half the speed of what we get at The Age offices according to a speed test on Wednesday, but potentially much more than many rural and remote users have been stuck with. At the test facility we tested popular sites such as news websites; Google Maps and Street View; the ABC's iView; and Netflix. We were able to run video on Netflix and iView, plus a Skype video call, simultaneously with no disruption to quality or speed. A 4K video on YouTube at 2160p resolution struggled a tad, with minor amounts of jerking and buffering even after having waited for the video to load first. However still running high definition at 1440p the same video performed just fine. NBN noted these were test examples only, with various factors potentially influencing results in the facility. Williams also stressed NBN promises speeds "up to" 25Mbps download and 5Mbps upload to retail service providers on the top speed tier. He said NBN's prerogative was to deliver as consistent a level of service as possible.
*Official and unofficial responses today suggest that customers using Sky Muster™ satellite service can expect speed up to 25Mbps for downloads, and up to 5Mbps for uploads. These speeds will vary based on peak and off-peak hours. Peak hours are typically early evening hours—times when most Internet users are likely to be home and connecting to the web.
Built into the design of the LTSS network is a smart learning system called an "acceleration machine" or "performance enhancing proxy". It basically learns all about the web pages people are viewing across the network and remembers the pages for next time so it can load them quicker. The system was developed specifically for the NBN satellite service with partner Viasat.
In February 2018, NBN Co awarded remote communications and IT solutions provider Speedcast with a 10-year, $184 million contract for enterprise-grade satellite services. Speedcast subsidiary Speedcast Managed Services will partner with NBN Co to design, build and manage enterprise satellite services for the state-run broadband provider.
Learn more about Custom MMIC’s space qualification capabilities here: https://www.custommmic.com/space-qualified-mmics/
Learn more about the CMD162 LNA and other space ready low noise amplifier MMICs here: https://www.custommmic.com/low-noise-amplifiers/