The Ariane 5 lifts off from Kourou, French Guiana. Image: Arianespace.
Inmarsat’s S EAN satellite for the European Aviation Network (EAN) inflight connectivity service has been launched from French Guiana aboard an Ariane 5 rocket.
The launch, designated VA238, took place at 21:15hrs UTC on Wednesday 28th June 2017 from the Kourou Space Centre. The launch had been delayed a few minutes from its scheduled time after a “red” authorisation condition was detected during the pre-launch phase.
The satellite is a dual-purpose “condosat”, comprising the Hellas Sat 3 and Inmarsat S EAN. Hellas Sat 3 will deliver direct-to-home TV and telecom services.
The satellite has been initially launched into a highly-elliptical orbit with its initial apogee point (the furthest point from Earth) at about 36,000 kilometres and its perigee just 250 kilometres from Earth.
A series of thruster firings will then be made to circularise the orbit and bring the satellite into its final geostationary position at 39 degrees east.
Initial testing of the EAN payload will be handled through Inmarsat’s Nemea satellite access station (SAS) in Greece and the satellite should be ready for use in August.
European Aviation Network
The full European Aviation Network service is scheduled to launch in the second half of 2017. This comprises a ground-based LTE network built by Deutsche Telekom plus links from the 5.8-tonne S-band satellite, built by Thales Alenia Space.
The 300 LTE-based ground stations will provide the air-to-ground connection to aircraft and the satellite will provide coverage over water and in regions where it has been difficult to install the cellular network.
Deutsche Telekom says the beauty of the ground segment is that it can be scaled around airport hubs and busy flight routes as required.
A system on board the aircraft automatically determines what signal – satellite or ground – is best and routes the data across the best/fastest channel accordingly.
Frederik van Essen, SVP Strategy and Business Development, Inmarsat Aviation, said: “Because we can use both a satellite and ground segment we can use two very small antennas on the aircraft, weighing around 8-9kg in total.”
“The satellite antenna is a slimline fuselage-mounted design from Cobham. The LTE air-to-ground antenna, which is tiny and can fit in your hand, is mounted on the underside of the fuselage,” van Essen said. “These offer low drag and therefore have a smaller impact on aircraft fuel consumption.
“Our launch partner IAG group will equip more than 300 aircraft, with the first service introduction expected in in 2018. We expect 90% of its short-haul fleet will be equipped by early 2019,” he said.
Deutsche Telekom says that tests over the air-to-ground segment of the European Aviation Network in southern UK have seen data speeds already exceeding those seen over Inmarsat’s Ka-band satellite-based GX Aviation system.
“Test flights over the UK showed a solid 70Mbps from the ground network to the aircraft, reaching up to 90-100Mbps at times,” said Rolf Nafziger, SVP International Wholesale Business, Deutsche Telekom.
By comparison, GX Aviation was designed to offer around 30-50Mbps to the aircraft, depending upon the antenna type in use, although Inmarsat says this will increase with future modem developments.
Nafziger said: “We always want to provide the best connectivity, wherever our customers are.
“There are 2,500 flights across Europe every day and half a billion passengers flying every year. They want to be connected and we needed a new technology for the dense airspace in the region.
“The EAN ground network is unique — stretching from Portugal to Romania, and from Sweden to Greece.
“We have completed the EAN network build-up in five countries, but the total is 30 (28 EU countries plus Norway and Switzerland) so we still have a way to go. But it will be completed by the end of 2017,” Nafziger said.
“The network will offer low latency, be very fast, and very scalable.”
Nafziger said that Deutsche Telekom would not rule out expanding the EAN to countries outside of the EU, if spectrum and regulatory hurdles could be overcome. An obvious country for future expansion, for example, might be Turkey.
But what speeds can be expected over the satellite segment?
Inmarsat S-band satellite
While the satellite is “only” S-band, Inmarsat says that it can use digital processing to dynamically allocate bandwidth as required.
Inmarsat’s SwiftBroadband uses frequencies around 1.6GHz and up to four 5MHz bearers can be combined or bonded to provide around 1.4Mbps or so. But the EAN uses S-band frequencies around 2-4GHz and has up to 2 x 15MHz of spectrum available.
It says speeds from the satellite will be in the “megabits rather than hundreds of kilobits per second” range.
“Get Connected” will provide you with the results of any speed and usability tests just as soon as we get invited aboard an EAN-equipped aircraft, probably in very late 2017 or early 2018.
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