Comments on: Why your in-flight Wi-Fi is slow and expensive: It’s all about the pipe http://gigaom.com/2012/09/19/why-your-in-flight-wi-fi-is-slow-and-expensive-its-all-about-the-pipe/ Tue, 18 Jun 2013 05:04:45 +0000 hourly 1 http://wordpress.com/ By: Martijn Moret http://gigaom.com/2012/09/19/why-your-in-flight-wi-fi-is-slow-and-expensive-its-all-about-the-pipe/#comment-1219447 Fri, 30 Nov 2012 12:33:53 +0000 http://gigaom.com/?p=564186#comment-1219447 Amusing comments from people who have been lying under a rock (there are more device than just laptops), to semi-philosophers (we might want to be connected everywhere if we choose to do so), to physics-fundamentalists (it is no miracle, but still very cool, as is a picture from a bot on Mars).

Thanks for a very good and clear written article. Clearly the market (demand) is there, and we are just at the beginning of a changing onboard experience. Even without internet connectivity, possibilities to connect devices to each other onboard are endles, e.g. for crew-passenger interaction.

]]> By: glenmorehomes http://gigaom.com/2012/09/19/why-your-in-flight-wi-fi-is-slow-and-expensive-its-all-about-the-pipe/#comment-1081023 Mon, 15 Oct 2012 17:40:26 +0000 http://gigaom.com/?p=564186#comment-1081023 Considering that a satellite can transmit its data to ground at rates exceeding a gigabit a second at a speed of 18,000 mph; transmitting wi-fi from an airplane at 500mph is child’s play.

This isn’t a challenge of physics, it’s a challenge to provide the service at a low price.

]]> By: Joe http://gigaom.com/2012/09/19/why-your-in-flight-wi-fi-is-slow-and-expensive-its-all-about-the-pipe/#comment-1067564 Thu, 11 Oct 2012 20:24:28 +0000 http://gigaom.com/?p=564186#comment-1067564 It has nothing to do with Connexion. Its based on technology from a US company called iDirect.

http://www.idirect.net/~/media/Files/Panasonic/Panasonic%20Article.pdf

]]> By: Ben Nachman http://gigaom.com/2012/09/19/why-your-in-flight-wi-fi-is-slow-and-expensive-its-all-about-the-pipe/#comment-1021378 Thu, 27 Sep 2012 12:28:18 +0000 http://gigaom.com/?p=564186#comment-1021378 please detailed information.
Dr. Ben Nachman
ben@bizness.co.il

]]> By: Satellite Spy http://gigaom.com/2012/09/19/why-your-in-flight-wi-fi-is-slow-and-expensive-its-all-about-the-pipe/#comment-1019720 Wed, 26 Sep 2012 16:51:23 +0000 http://gigaom.com/?p=564186#comment-1019720 Well, this little post has fired up a few folks!
Stacey has got it right, as has HiSpeedWiFi.

Never mind whether it’s Wi-Fi, phone, or whatever from the passengers’ point of view in the plane. That’s just bog standard TCP/IP stuff like you get at home. But imagine a home with 400 people all downloading videos at the same time. That’s a heck of a large composite data rate!

The fundamental issue is the data rate that has to be supported between the plane and the satellite for a given quality of service (e.g. BER >1 in 10**7 for 99.9% of the time). That comes down to a few things, including:
(1) The satellite transmit power (EIRP) and the plane terminal’s EIRP & G/T.
(2) The issues of the active tracking antenna on the plane, be it a mechanical, steerable dish or a phased array. For a good design, allow 3dB in the link budget.
(3) The effects of Doppler shift due to the plane’s movement, and how the modem’s carrier & clock recovery circuits (algorithms) cope with this.
Couple this with the performance of modern modems using ACM (adaptive coding & modulation). This means scaling the data rate according to the time-varying channel degradations.
(4) Propagation conditions – signal fading due to atmospheric attenuation, scintillation etc. This is frequency-dependant, but planes are usually above the weather, so it’s not such an issue. Perfect for the next generation, high-capacity Ka-Band frequencies.
In a nutshell, it comes down to how big a tracking antenna can be mounted on an aircraft.

OK, this is all boring techy stuff. But this is the reality! Very good blog post, Stacey. :-)

Background: My company (CSR Ltd) developed the very first satellite modems used for passenger comms on commercial aircraft in the late 1980s – taken up by British Airways (SkyPhone service), Singapore Airlines, Lufthansa et al.
Personal website http://www.satellitespy.net and @satispy on Twitter.

]]> By: MM http://gigaom.com/2012/09/19/why-your-in-flight-wi-fi-is-slow-and-expensive-its-all-about-the-pipe/#comment-1019015 Wed, 26 Sep 2012 12:00:46 +0000 http://gigaom.com/?p=564186#comment-1019015 Keep in mind, the antenna is required to track the satellite, basically compensating for the satellite’s fixed position while moving. That is the real challenge, not the speed at which the radio waves reach the antenna.

]]> By: Richard Skaife http://gigaom.com/2012/09/19/why-your-in-flight-wi-fi-is-slow-and-expensive-its-all-about-the-pipe/#comment-1018730 Wed, 26 Sep 2012 09:42:26 +0000 http://gigaom.com/?p=564186#comment-1018730 WiFi access on commercial aircraft is all about the economics of the service. The cost driver is the backhaul from the aircraft, either satellite or direct to the ground (a la Airlink). There simply are not enough passengers wishing to use the service to make the business case close so you have to regard the overall system as an aircraft information service, providing information services to both passengers and the airline. The airline services are such things as real time credit card clearance, aircraft cabin operational management (maintenance reports to prepare cabin job cards in advance etc, passenger information – connecting flight data etc – using this system instead of ACARS), then you can get into aircraft data systems – engine performance etc for managing the aircraft maintenance, electronic flight bag…. the opportunities are almost endless. Once you view the service in these ways the business case for satellite backhaul begins to make sense. Standalone passenger services is a pretty tough case to make.

]]> By: Hunter http://gigaom.com/2012/09/19/why-your-in-flight-wi-fi-is-slow-and-expensive-its-all-about-the-pipe/#comment-1017154 Tue, 25 Sep 2012 15:09:30 +0000 http://gigaom.com/?p=564186#comment-1017154 Yeah, Connexions (now known as Boeing Broadband Satellite Network) to the govt = ~ $60M/year lease…that’s a lot of movies

]]> By: HiSpeedWiFi http://gigaom.com/2012/09/19/why-your-in-flight-wi-fi-is-slow-and-expensive-its-all-about-the-pipe/#comment-1011419 Fri, 21 Sep 2012 21:31:20 +0000 http://gigaom.com/?p=564186#comment-1011419 Actually this isn’t about how fast the airplane is moving with respect to the speed of radio waves. It’s about how rapidly the environment or the “channel” in which the radio waves are traveling to the plane is changing. The faster the plane moves, the more quickly the channel changes, and the harder it is to compensate for these changes to recover the data encoded in the radio waves. As usual, wikipedia has the details: http://en.wikipedia.org/wiki/Fading

]]> By: boneman http://gigaom.com/2012/09/19/why-your-in-flight-wi-fi-is-slow-and-expensive-its-all-about-the-pipe/#comment-1009922 Fri, 21 Sep 2012 10:41:49 +0000 http://gigaom.com/?p=564186#comment-1009922 How about NO wi-fi. Do we REALLY have to be connected everywhere? Try reading a book for a few hours.

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