21.04.2008
The iPhone video threat: Can networks keep up?
With 9 billion video downloads last year over wireless, business and cell
networks are becoming overwhelmed
Be careful what you wish for. The iPhone has
realized the old promise of the mobile Web. But it's not clear
whether the wireless networks can handle the load.
With news that Apple's little cell phone now
accounts for
more mobile Web traffic than any other device in the U.S. --
and is No. 2 globally -- the issue of whether or not Web-enabled
wireless devices will overwhelm cellular and Wi-Fi networks is
about to come to a head.
Of course, it's not just the iPhone. Adding
to the growing ways to access the Web over wireless is the new
class of ultraportable PCs from the likes of PC stalwarts
Lenovo and
Hewlett-Packard and startups such as Oqo. Weighing in at four
pounds or less, these devices are easy to carry around, and they
offer displays that are far better than a two-inch screen.
The issue is not Web access, per se. Instead,
it's access through the Internet to video and other multimedia
content, which newer devices make such a simple and enjoyable
experience.
Statistics from ComScore say that 9.1 billion
videos were viewed online by July 2007. Last year, according to a
New York Times article, video uploading and downloading from sites
such as YouTube "consumed
as much bandwidth as the entire Internet did in 2000." The
trend is only expected to grow. In four years, according to
MultiMedia Research Group, there will be 240 million video-enabled
phones, as well as 63.6 million IPTV (Internet Protocol TV)
subscribers by 2012.
Until recently, mobile Internet traffic has
been mostly burst transmissions, such as e-mails, that can be more
easily managed across the network without affecting the user
experience. But video hogs the network for a good length of time,
in the process squeezing out other traffic.
Most networks institute collision avoidance
techniques so that various types of traffic don't get in each
other's way, but that's harder to do with streaming media such as
video. Typically, a local access point or cellular receiver will
detect a video stream and make other traffic wait until the "gap"
between video packets. Streaming media get priority because if
there are too many gaps, the video or audio fragments. So other
traffic such as Web pages and e-mails are forced to wait until the
next available gap, likely leaving many users dissatisfied with the
effective performance.
Organizations are cracking down
John Collins, the CIO at Prairie Cardiovascular, a Midwest
health care company with 28 facilities, is already feeling the pain
from the doctors coming into one of his facilities with their
brand-new iPhones. Collins has faced numerous incidents of slowing
networks and was forced to institute a policy that completely
turned off wireless streaming video to its staff of doctors,
nurses, and administrators. Collins also uses SurfControl from
WebSense to block all shopping sites.
Prairie Cardiovascular's policies came about
after the health care organization began experiencing serious
problems with slow access over its Wi-Fi network. IT analyzed the
system using a combination of Aruba Networks' built-in diagnostics,
SurfControl, and features on its Nortel switch to identify and
manage access, ultimately identifying shopping sites and video as
the root cause.
"Most of these [28] facilities have
VPN back to me. What would happen to the network if a doctor wants to
stream a soccer match from India? I can't allow it. I need my EMR data
and diagnostic imaging data going back and forth during the day," says
Collins.
Nevertheless, after vociferous
complaints from a number of physicians who wanted to do watch video
streams over their handhelds, Collins relented just a bit and opened
up the network for doctors' personal use for a half hour during the
day and one hour at night.
Prudential Fox Roche, the
third-largest U.S. real estate firm, also had a problem with employees
bringing in their wireless devices for video surfing, so it too tried
to limit the use of video-oriented sites such as YouTube over its
wireless network. "We do get overloaded with streaming," says William
Friemann, the firm's vice president of technology operations,
security, and compliance. Prudential offices typically have a single
T1 line as the backbone for its wireless network, and a lone user can
hog three-quarters of that with a video download. In fact, one
employee was terminated for his refusal to stop streaming. "It was
constant even after numerous warnings," Friemann said.
But Friemann says he can't shut down
video streaming because Prudential also uses streaming for e-learning;
the marketing department uses the technology extensively as well.
With tight budgets, Prudential won't
increase bandwidth to satisfy YouTube users. "We are just not going to
buy additional bandwidth," Friemann notes.
Handset trade-offs are a key
culprit
But the real problems have only just begun, according to Aruba
Networks CTO Merwyn Andrade. Andrade points out that while
high-performing 802.11a and 802.11n networks might alleviate some
congestion, for a number of practical reasons, Wi-Fi-enabled handsets
will not be easily or quickly upgraded to these more capable Wi-Fi
standards.
The 802.11b/g technology used in
handhelds offers only three non-overlapping transmission channels (1,
6, and 11) for use with video. By comparison, 802.11a offers 20-plus
channels. But handset vendors are trying to cut costs, and 802.11b/g
chips cost less than 802.11a or 802.11n units. So handset makers use
the lower-bandwidth technology.
Furthermore, the chips that work on the
higher bandwidth consume more power, either requiring heavier,
pricier batteries or shortening talk time. Vendors believe that
users prefer more cell phone time between recharges over faster
download times, says Andrade.
These cost and power reasons explain
why it will be a long time before users see 802.11a or 802.11n Wi-Fi
in cell phones, Andrade says. Thus, users and network managers may
soon be stuck between the proverbial rock and a hard place. Because
Wi-Fi is faster than cellular 2.5G technology such as the AT&T EDGE
network that the iPhone uses -- "the 2.5G link on the iPhone sucks,"
says Andrade -- the Wi-Fi networks will soon be saturated with demand
for video.
Time for new policies
Today, the new breed of Web- and video-capable mobile devices
aren't generating enough traffic to hurt existing Wi-Fi and cellular
networks, except in times of major disasters, says Gerry Purdy, chief
analyst at Frost & Sullivan. "Current cellular capabilities are
enough," he says.
When handsets become 4G-capable and,
thus, can transmit hundreds of megabits per second, they will become a
major issue, as users go beyond downloading videos and actually start
creating videos on their mobile devices.
"Once you start using your phone as a
camcorder and upload video to post to Facebook, there can be the
potential for problems. A real-time video taking place in say Hong
Kong by one person is OK, but if you have 10,000 people doing it,
that's a lot of bandwidth," says Purdy.
To avoid nasty surprises later, Purdy
says that IT has to start getting creative now in terms of making
policies that haven't existed before: "Watch for policy development
about rich media. An insurance adjustor taking a video will use a lot
more bandwidth than a static picture, so companies need a policy about
who can do what. It is all a balancing act."
Restrictive access policies may be a
short-term solution to the problem. However, the long-term solution
will more than likely be increased bandwidth capacity.
And although IT people may not gain a
friendly ear as they try to convince a belt-tightening board that they
need more bandwidth to accommodate employees using FaceBook and the
like, paying for more capacity may become a necessity. "I would really
have to justify spending on increased capacity," Friemann says.
Friemann and other IT executives may
be able to do that once multimedia and video move from a consumer
application to become part of a business solution.
© Ephraim Schwartz
Source: www.infoworld.com
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