Subject: [NEXTEL-1] New spectrum adds Wi-Fi channels #105: [1]

From: [email-masked]
Date: Tue, 24 Jun 2003 09:54:57 -0400

New spectrum adds Wi-Fi channels #105: [1]
Source: InfoWorld

Arrival time: 2003-06-24

FCC proposal could breathe life into 802.11a

WITH THE FEDERAL Communications Commission proposing to nearly
double 802.11a's available bandwidth, Wi-Fi is on course to become as
available as the air it travels through.

Posted last week, the FCC proposal would add 80 percent (255MHz) to
the 300MHz of spectrum currently available in the 5GHz band. The
additional spectrum would reside in the middle band, from 5.470GHz to
5.725GHz.

The change would offer many major benefits, according to the FCC.

"The additional bandwidth means you can have higher density of use in a
given geographical area because there is much more spectrum available. It
can also be channelized in many ways," said Edmond Thomas, chief of
the office of engineering and technology at the FCC in Washington.

The bandwidth proposal would increase the number of channels 802.11a
can operate on to 24. At present, 802.11b has three channels available;
802.11a has 11.

The added spectrum would also match the 5GHz middle band currently
allocated in Europe.

"The Europeans decided to use the middle band to get out of the way of
radar," said Craig Barratt, CEO of Atheros, a Sunnyvale, Calif.-based
manufacturer of IEEE 802.11x chip sets.

Under the FCC guidelines, additional spectra must use DFP (Dynamic
Frequency Protection) so that when a WLAN detects radar using the
same band it can switch to another channel.

The FCC chose the same band as Europe's in order to have overlapping
bands throughout the world, according to Ken Dulaney, chief wireless
analyst at Gartner in San Jose, Calif.

"This simplifies things a lot. If you buy a radio in a country that doesn't
have support for that band, you can't use it," Dulaney said.

Given the proposed increase in spectrum, companies would have more
flexibility in allocating specific channels for particular applications.

"If you have enough channels set aside for dedicated use, your QoS
[quality of service] problems are gone," said Leigh Chinitz, CTO of Proxim
in Sunnyvale, Calif.

Specifying channels will also make the use of VoIP (Voice over IP) far
more practical, Chinitz said, adding that VoIP requires the WLAN to offer
continuous coverage and capacity.

"Voice over IP will be carried over wireless LANs by allocating channels
just for VoIP," Chinitz said.

The proposed spectrum addition is also receiving a warm reception from
Cisco Systems. Christine Falsetti, Cisco's director of wireless and
mobility marketing, said the decision to make the 5.4GHz band usable in
an unlicensed way is a positive tep.

"Access to this spectrum allows more channels and innovation," Falsetti
said.

But Gartner's Dulaney believes the FCC proposal does not go far enough.
Dulaney conceded that, in the short term, the increased number of
channels would ease conflicts between competing networks but added
that the open bands, IEEE 802.11x, are too open.

"We need an unregulated technology in a regulated band," Dulaney said.

There are a number of other issues surrounding the FCC proposal that
could delay deployment of devices capable of accessing the additional
spectrum.

Most of the hardware available today is not tuned to cover the proposed
spectrum. In fact, many 802.11a devices cover only the lower and upper
bands.

"It may be possible that current hardware can't handle the middle band. It
will probably require new hardware," Chinitz said.

If the United States formalizes the DFP rules, then the Atheros chip,
which already complies with the European standard, will be compliant and
will address the entire 5GHz band. But if the United States adopts
significantly different rules, which Atheros' Barratt said is unlikely but
possible, the deployment of access points that cover a larger range of
channels will be some time in the coming.

Barratt said such a situation would be akin to a television that works only
on a few channels.

"For the present, IT departments should make sure that they buy access
points that address the entire 5GHz spectrum," Barratt said.

At the least, Wi-Fi vendors would need to flash the access points with
upgraded software for it to access the increased capabilities.

With the unprecedented support of the FCC and technology improvements
already in the pipeline, the future is bright for Wi- Fi.

Based on 24 channels at 54Mbps, users could share a wireless Ethernet
throughput of 1Gbps, enough to replace many wired networks. Using the
same 24 channels at a more conservative 24Mbps, users could share
600Mbps.

According to Dulaney, the IEEE 802.11n committee is also examining the
possibility of doubling up the bandwidth by bonding channels.

The only dissenting note comes from a cellular industry executive
sounding like the fairy in Sleeping Beauty not invited to Beauty's
christening. "Wi-Fi has become the golden child, and the wireless carriers
are like the red-headed stepchild. We spend so much time to get more
spectrum, and we are paying through the nose for it. But it is important not
to get too caught up in one technology like Wi-Fi. Look what happened to
eight-track tapes," said the cellular executive, who asked not to be
identified.

QUICK TAKE

The FCC is proposing to make an additional 80 percent spectrum available
in the 5GHz band.

Wi-Fi to get more bandwidth

infoworld.com/news

Atheros Communications atheros.com

Federal Communications Commission fcc.gov

Proxim Wireless Networks proxim.com

BOTTOM LINE: With the increase in bandwidth proposed by the FCC,
enterprise-level companies will be able to dedicate wireless channels to
specific mission-critical applications, thereby making QoS a nonissue.

http://cnniw.yellowbrix.com/pages/cnniw/Story.nsp?story_id=39694967&ID=cnniw&scategory=Telecommunications%3AWireless&

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