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ET phone home Bearing in mind the costs

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ET phone home Bearing in mind the costs Powered By Docstoc
					                                                                                     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!’



        18                                                                                               N e w E l e c t r o n i c s w w w. n e o n . c o . u k 2 3 M a y 2 0 0 6

				
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