Get documents about "ET phone home Bearing in mind the costs
Document Sample
number poses a risk to the safe operation of the
aircraft. Explains Rainer Koll, vice president of
Thales Aerospace Division and general manager
of Thales Avionics: “As the plane takes off, the
link quality degrades, and the mobile phone’s
power control increases
transmission power to
try to maintain the
link with the ter-
restrial net-
work. A
phone radiating at 1W
might interfere with the very
sensitive navigation systems
onboard. Also, the ‘phone is often
attempting to log onto more than
one cell on the ground at once,
because the phone at that height can see
perhaps two or three cells – thus interfer-
ing with ground based networks too.”
Deemed largely for ‘in emergency’ use only,
the current solution – a phone which is hardwired
to your seat which can be accessed with a swipe
of your credit card – is typically charged at $8 to
$10 for one minute. Meanwhile, whilst a satellite
phone might technically work in flight, the
Mobiles get wings!
Satellite based mobile
E
T phone home. Bearing in mind the costs switching technology would not have been in
involved, it’s no wonder he kept it short place to deal with plane’s movement.
phone services will allow …Unless you are blessed with extraterres- The promise of being able to use a mobile
trial powers or a large bank account, communi- phone in the air has been talked about for years,
airline passengers to make cating with those in the air or vice versa has been yet it is only now coming to fruition. Indeed, it is
a costly exercise. And if you had your phone on just one aspect of a range of onboard applications
calls from on high. by mistake, then it might have proved costly for that will be available in the future. Key to achiev-
the airline too ... ing it, believes Koll, is the ability to enable safe and
Mobile phones, for safety and simple accessi- minimal interference of gsm phones at prices com-
By Vanessa Knivett. bility issues, have been categorically prohibited in parable to an international roaming charge. But
flight. Whilst the current systems and regulatory there is a third issue – finding a way to make the
environment allow for perhaps one or two mobile use of mobile phones on planes socially accept-
phones to be left ‘on’ onboard, more than this able. He notes: “Passengers like the freedom of
16 New Electronics w w w. n e o n . c o . u k 23 May 2006
IN FLIGHT COMMUNICATIONS COVER STORY
making phonecalls, but don’t want to be dis- the space equivalent of a global cellular system.
turbed. The solution is to build in the capability Located in a geostationary orbit, three or four satel-
to turn phones to silent mode during certain lites provide global coverage. Each has close to 300
phases of the night or to create designated zones spot beams (in a honeycomb pattern), each com-
in the cabin – phones can be available in ‘tap, not parable to the cell of a communications network.
talk’ mode. The latter might be particularly useful A satellite antenna is located on the top of the
on larger aircraft, like the Airbus A380, which will plane on its centreline. As the aircraft banks,
have public bar areas where passengers would be turns, pitches and yaws, a beam steering function
able to use their phones more freely.” steers a torchlike beam which is always focused on
Today, OnAir – one of the companies work- the satellite. If a high gain antenna is used, data
ing to make this a reality – already offers a range rates of 432kbit/s per channel can be achieved –
of non GSM services such as in seat telephony, in as Koll is at pains to point out, that’s 432kbit/s
seat text messaging, as well as Webmail and Chat channels dedicated to each aircraft, rather than
from passengers’ laptops, which are currently shared with other aircraft in the same area, so that
used at times other than take off and landing. But a guaranteed level of service is achieved.
in early 2007, OnAir will introduce a GSM net- Explains Koll: “This new satellite system offers
work on board aircraft, allowing passengers to use more flux density – more rf power is available per
their own mobile phones to make and receive square feet – so the user terminals can be smaller.
calls and text messages, and to send and receive In this case, the I4 satellites have resulted in the
data over GPRS. It is working with Thales, which use of antennas that are four times smaller than
is responsible for the portion of the communica- existing systems and three times less weighty. This Approval is being sought for
tions stream that lies outside of the airplane, and has had a positive impact on the performance of gsm communications by aircraft
Airbus, a global aircraft manufacturer that will be the airplane as there is less drag and fuel con- passengers. Currently, mobile
responsible for the system integra- sumption, and it is easier to integrate.” communication is categorically
tion aspect of the project. According to Koll, a similar evolution has hap- prohibited inflight because of
OnAir, meanwhile, contributes pened in the rest of the OnAir mobile communi- concerns that the signals will
the picocell, providing gsm coverage cations system. One interfere with the aircraft’s
using the 1800MHz band, which cov- of the main compo- sensitive electronic systems.
ers the vast majority of GSM compatible nents is Thales’ Swift-
phones wordwide; a channel selector, BroadBand satellite data unit
allowing cabin crew to access force modes to (sdu). Housed in a single six mcu enclo-
prevent voice calls; and provides service pro- sure, the solution provides physical and
vision, via an air to ground link. logical partitioning to enable it to satisfy both
The picocell prevents any mobile phones on cabin and cockpit requirements safely. Says Koll:
board from attempting to log on to terrestrial net- “This system has been reduced in size by about
works. Because it emulates a gsm network, much 50%. The size reduction has been achieved using
lower transmission power is required from the state of the art, in bought design, efficient compo-
mobile phones on board, effectively forcing nent use, and efficient power use. It uses a high
phones to their lowest power setting (approxi- power amplifier of 30W that generates tremendous
mately 10 to 15mW) so they stay within the heat. Previously, this would have been housed sep- Thales’ SwiftBroadBand satellite
power limits for the safe operation of the aircraft arately. However, the use of forced air cooling sys- data unit is typically housed in
– and taking care of that ‘forgotten’ mobile phone. tems – which are already available within the the avionics bay. There are
Comments Véronique Blanc, cto of OnAir: “A aircraft – ensure that heat is kept to a minimum system diagnostics on the front
picocell was always identified as the right kind of and that the amplifier can be housed within the panel, indicating for example,
vehicle for the solution onboard. Whilst these are data unit.” antenna or cable faults, thus
commonly used on the ground, we had to go Competitive solutions are in existence, with enabling line maintenance.
through a stringent certification process to enable broadband data communications being
it to be used onboard. Meanwhile, the channel offered over Ku-band satellite
selector is a totally new component, ensuring that systems under experimental
mobile phones onboard see the local network that licenses. Koll contends that
we provide as the one to connect to. Again, ensur- whilst, on the surface, these offer
ing that the channel selector met avionics require- more bandwidth (2Mbyte/s or
ments was a challenge.” so), SwiftBroadBand’s dedicated
DebutArt: Oliver Burston
Providing the enabling satellite network for this communications pipe to individ-
application is Inmarsat’s new SwiftBroadband ual aircraft enables tens of users
fourth generation satellite service (I4), which for simultaneous gsm voice calls.
became available at the end of 2005 and provides Blanc contends that this allows
New Electronics w w w. n e o n . c o . u k 23 May 2006 17
IN FLIGHT COMMUNICATIONS COVER STORY
more people have 2.5G gps and gprs phones.
Figure 1: Swift BroadBand system diagram
When 3G services on the ground have developed
to the point of penetration that we currently see
GSM/ GPRS IFE for gsm, probably we will reconsider.”
Meanwhile, there are hurdles to overcome
on board before a gsm service reaches the skies. Spectrum
channel selector SwiftBroadBand use and the right to use mobile telephones as the
GSM/ WiFi aircraft moves over a number of different coun-
Pico-cell server tries during a flight remain outstanding issues.
control panel
There are also questions over the interface
between the telecommunications aspects of these
IRS services and the aviation aspects. With nationally
WiFi
based telecom regulations, nationally based solu-
tions will be required. However, given the inter-
The system has four main • A server to manage communications national nature of aviation, it will be necessary for
components: centrally, establishing calls with the these national solutions to be harmonised, if not
• A picocell to provide the radio interface ground segment over the air to ground internationally, at least regionally.
to mobile phones in the cabin. link, and interfacing with aircraft According to Blanc: “A lot of work has been
• An onboard channel selector to ensure systems. undertaken so far by the industry and regulators,
that onboard mobile phones operate in • An air to ground modem to allocate air particularly in Europe under the umbrella of the
a mode compliant with certification and to ground resources according to the CEPT, to create a framework for the regulation of
regulatory requirements. demands of the server. the system. OnAir has proposed that the State
responsible for the telecoms licensing regime of
plenty of headroom for OnAir’s offering: “When
we defined requirements for the system initially, the
capacity was driven by research and takeup antic-
ipated. The baseline system can accom-
modate up to 14 simultaneous calls on
a narrow body aircraft, and there is the
option to upgrade that to up to 28 calls.
Initially, we see airlines taking the standard sys-
tem. We are confident that the capacity that we
have defined is adequate, but in addition to that,
text and gprs can be used as well – but these aren’t
real time, so don’t have such an impact on capac-
ity.” Wider body aircraft, predominantly used for
OnAir’s baseline system longer haul flights, have different usage patterns. If
can accomodate up to 14 more capacity is needed, the system has been an on board mobile phone system be the state of
simultaneous calls on a designed so that more picocells could be added. registration of the aircraft, provided there is no
narrow body aircraft. Bandwidth becomes of interest when you are harmful interference with either terrestrial net-
looking at full web browsing through your laptop. works or avionics systems.”
However, Koll notes: “Airlines, typically, don’t The Electronic Communications Committee,
want to open the service to full web access because which handles the CEPT’s telecommunications
they cannot control site content. Instead, the activities, considered OnAir’s framework in March
server onboard the aircraft will upload a cached and doesn’t foresee outstanding regulatory issues.
copy of popular webpages, which will be updated After the review of a Compatibility Report, being
at regular intervals. So users will actually log onto undertaken at the moment, there will be a public
the onboard server and access speed will be fast consultation of two months and a final decision is
because users are communicating with the server.” likely to be reached this Autumn. Meanwhile, a
OnAir will not offer 3G services, such as video number of airline operators – including British
streaming and tv over mobile. It’s worth noting that operator bmi – have signed up to a trial that will
some entertainment options on wide body aircraft take place once the necessary telecommunications
would compete directly with some 3G services. regulatory framework has been put in place.
Explains Blanc: “Today, our business is about So, whether you welcome the news or not, it
offering a mainstream service, allowing people to won’t be long before the person in front will be
do in the air what they do on the ground. And shouting: “I’m on the plane!’
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