Rants
Questions
Soapbox
Best Practices
Apply today for a FREE subscription to CIO Magazine!
Wed, Jun 24, 2009 18:55 EDT
Topic: Networking
Current Rating: |
Surfing the Air for Business and Pleasure;
Inflight wireless at your airline seat
By Andrew Froehlich
Returning to Chicago after an international trip, I changed planes in Atlanta and was about to board a Delta flight to
the windy city on a McDonnell Douglas MD‐88 craft, when I
spotted on the outside of the craft next to the entry door
the familiar Wi‐Fi logo. Tired though I was, a surge of
adrenalin perked me up. Finally, I thought, my first chance
to test in‐flight wireless.
Delta Airlines began offering wireless on select flights
beginning in early 2009 using Aircell's Gogo service. Fact
is, even though I was excited to try it, I wasn't expecting
much. Here’s what happened:
I found my seat in coach and pulled my netbook out of my
carry‐on bag so I’d be ready to boot up once we reached
10,000 feet. In Delta's Sky magazine I found instructions on
how to use the Gogo service. Straightforward and identical
to any wireless hotspot found on the ground I learned you
simply turn on your 802.11b/g wireless card and connect to
the openly broadcasted SSID of "Gogoinflight". Once connected, you open a web browser and are directed to
the Gogo wireless purchase and login screen. Simple enough.
I settled back to wait for the climb to 10,000 feet. I was
like a kid with his first computer, impatient to get started.
Partly it was because I had sat on many previous flights
bored out of my mind and dreaming of the day when I could
check my email, do some work and chat with friends while
in‐flight.
At the designated altitude, I began booting. Ordering
Internet service is fast and surprisingly inexpensive. Gogo
on this short flight of less than three hours was $9.95. For
flights longer than 3 hours, it’s $12.95. There is also a
"mobile-only"option with a flat rate of $7.95 no matter how
long the flight lasts.
After my credit card was charged, I was off and running. I
pointed the browser to the speakeasy.net Internet speed tester,
expecting to see download speeds of less than 500 Kbps and
upload speeds around 128 Kbps. Pleased, I found that Gogo
was nearly three times faster than expected. Download speeds
were just over 1700 Kbps and uploads a bit over 300 Kbps.
Not bad. My next thought was, “sure it's got decent throughput
but what about response times?” I pulled up a command line
and ran a ping to www.google.com. Average response time:
204ms. Not super speedy but better than expected. To give
you an idea of typical response times to www.google.com,
I routinely get between 70ms and 100ms from my home DSL
connection. So while 200ms is half as responsive, it's
still respectable and good enough for me to
try out a VoIP service such as Skype but more on this
later.
It was at this point I realized I had no idea how the Gogo
wireless actually worked. Obviously, there had to be a
standard Wi‐Fi access point installed on the airplane. But
the connection from the access point to the ground 30,000
feet below was a mystery. I assumed that satellites were
used to beam my signal up and then back to earth and
ultimately to the Internet. The fast response times made
me reconsider this theory however. Using satellite
technology, it takes a relatively long time for data to be
beamed up thousands of miles into space only to come back
down. Because I was receiving such quick ping response
times, I knew Gogo had to be using technology other than
satellite. This was later proved correct when speaking
to an Aircell representative, owner of Gogo service. I
learned Aircell had prudently purchased US FCC rights to
install and use air‐to‐ground wireless frequencies. The company then created a blanket of wireless cells using
3G technology. Aircell, I was told by a representative,
had erected a national network of cellular towers
throughout the continental United States to transmit
broadband Internet connectivity to Gogo‐equipped aircraft.
Three small antennas installed on the outside of the
aircraft (two ATG antennas under the aircraft and one
GPS antenna on top of the aircraft) receive the signal
and convey it to the Gogo system in the aircraft.
Gogo then transmits a Wi‐Fi signal inside the cabin
for passenger use.
The cell towers use the same CDMA EV‐DO technologies as
cell phone providers use. The only difference is that the
Aircell service is engineered to transmit and receive
signals to jets flying overhead. I found it interesting
that the "new" technology of in‐flight Internet service is
not so new after all. It's simply using proven technology
in a slightly different way. The good news is it works
beautifully and that's what's most important.
Meanwhile, back on the plane, I tested all of the most
common Internet‐based applications. My MSN messenger
worked as expected. I loaded my Cisco VPN client and
successfully logged in and mounted remote server drives.
I uploaded and downloaded a few 50 Mb files with ease
through the VPN. Next was to attempt to stream a movie
from my Netflix account after disconnecting from my VPN.
I typically use my Macbook Pro for movie watching so when I logged into Netflix.com and picked a streaming movie
to watch it gave me a popup warning stating that I
needed to download and install Microsoft’s Silverlight
streaming software. No problem, I thought. But it was a
problem. The link to download the application did not
work. Was this the result of filtering
being performed by Gogo? Are they blocking all streaming
content? To find answers, I navigated to fox.com and
attempted to stream an episode of “24”. To my surprise,
this streaming was allowed by Gogo and “24” streamed in at
a speed comparable to my home DSL connection. So it was
obvious some streaming content was being blocked while other
content was allowed. I asked the Aircell rep about this
and learned MS Silverlight/Netflix is not blocked. However,
if the Silverlight plug‐in had been identified/classified as
a peer‐to‐peer file sharing or commercial file sharing
application, it would be rate limited to a very low bandwidth
i to not impact other users’ experience. After my experience
with Netflix and success with streaming Fox broadcasting
content, my next question was what else might be blocked or
rate‐limited? I booted Skype to see if I could make a VoIP
call from the air. If Gogo was blocking anything, it seemed
likely it would be Skype. Surprise. I was able to login to
Skype with no problem. Unsure if I was permitted to make
VoIP calls from the air I assumed since I was able to login
it must be permitted. As a courtesy to cabin‐mates I used
headphones and dialed my work extension for messages. The
audio during the ring was choppy and breaking up. When my
voicemail message kicked in, I could barely make out the sound of my voice asking me to leave a name and number. I
left a short message to see if the audio was better from
airplane to desk and simply poor from desk to airplane. It
too was unacceptable. This seemed to be odd as my response
times to Skype should be low enough to have decent call quality.
I asked the Aircell rep about it and learned VoIP may have been
blocked and/or crippled at the request of its airline partners
because of passenger aversion to the nuisance of too many
passengers disturbing other passengers who wanted only peace
and quiet. That probably makes pretty good sense. Thus, it is
against American Airlines, Virgin America, AirTran Airways and
Delta Air Lines policies for passengers to use VoIP in‐flight,
and Aircell has multiple protocols and practices in place to
prevent its use.
I continued during the remainder of my trip to test the ease
and functionality of using the service on mobile devices,
successfully connecting to Gogo on my iPod Touch and
streaming several YouTube videos and surfing the Internet
on Safari. The passenger seated next to me was also curious.
He had a BlackBerry Curve with built‐in Wi‐Fi which we tested.
Connecting and surfing the Internet was a snap with it, as
easy as it was with the iPod Touch.
By then the attendant came on the PA announcing we’d soon
be landing and all electronic devices must be turned off.
I was in Chicago already. Where’d the time go? It’d been
the best flight ever. From now on, whenever I fly the
continental U.S. I’ll do my best to book fights offering
Wi‐Fi. It’s a great way to travel.
~Froehlich is lead design engineer and owner of West Gate
Networks. He can be reached at
andrew.froehlich@westgatenetworks.com