Another major player in the commercial aviation satcoms market is Inmarsat, with its European Aviation Network (EAN), which will go live mid-year and cover all 28 member states of the European Union, plus Norway and Switzerland. Launched in September 2015, this hybrid system provides connectivity via an S-band satellite or via a new 4G Long Term Evolution (LTE) mobile terrestrial network of approximately 300 antenna sites. The terrestrial option offers the same speeds and capacity as satcom but requires a much smaller and lighter antenna mounted on the underside of the fuselage. The shorter distance that the signal has to travel also eliminates the time delay (latency) associated with satcoms.
Thales and Cobham SATCOM are working on the satcom portion system, with Cobham providing a Mobile Satellite Services terminal that exploits the latest advances in Broadband Global Area Network (BGAN) technology. Cobham SATCOM is also responsible for updating the Inmarsat BGAN ground infrastructure to accommodate S-band operation. Thales is overseeing the Complementary Ground Component terminal, which will automatically switch the aircraft system between satellite and terrestrial connectivity for optimal service delivery.
In December 2016, Inmarsat signed a contract with Arianespace to launch the satellite on an Ariane 5 rocket. This will take place at the Guiana Space Centre in Kourou, French Guiana in mid-2017. In fact, the satellite is a ‘condosat’ constructed by Thales Alenia Space, which incorporates a second telecommunications payload, Hellas-Sat 3. The satellite will weigh about 5.9 tonnes at launch and will be positioned at 39° East.
For the ground network, Deutsche Telekom and Nokia have adapted Nokia´s LTE base stations and Remote Radio Heads to the EAN frequency and built a specific base station antenna to track aircraft travelling at some 650kts, which needs compensation for the Doppler effect (frequency shift), and at altitude. Each base station will cover three cells, each of which will have an average range of more than 80km, up to a maximum of 150km, with a slight overlap for continuous coverage. While the satcom portion can cover all areas, the base stations cover all land masses. The base station locations are denser under the major airways that make up European airspace, to provide high network capacity.
In addition to the live network, the partners set up a full end-to-end ground network reference system in Nokia’s Stuttgart laboratory, including all components and integrated onboard equipment from Thales. These were thoroughly tested and validated and the first live connection in the field was accomplished in a broadband video conference with both parties connected via the dedicated EAN LTE mobile network.
In late November 2016, the first flight trials took place to test the performance of the EAN system, including the onboard equipment being provided by Thales and the ground network provided by Deutsche Telekom and Nokia. The airborne equipment was installed in a Dassault Falcon 20 business jet operated by Aviation Défense Service, a company specialising in providing airborne platforms for industry and armed forces to carry out trials, based in Nîmes. A few days later, the same aircraft was the chase plane and camera ship for the first flight of the Airbus A350-1000 from Toulouse.
The trials took place from Bournemouth in the UK, using four test sites located in the south-west of the country and proved that the network could successfully attach to the ground system. The systems performed multiple successful handovers between sectors and cell towers, and maintained a stable connection. The transfer of data to and from the aircraft was also tested. The actual performance and quality of the inflight datalink exceeded design expectations, according to Leo Mondale, President of Aviation, Inmarsat. >>
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