Clinton Jones Clinton.Jones at
Wed Apr 17 17:31:32 EST 2002

S. Robotics Doubles Wi-Fi Speeds
Wireless LAN products hit 22 mbps, retain backward compatibility with other
802.11b devices.

Peter Sayer, IDG News Service
Tuesday, April 16, 2002

U.S. Robotics (USR) has boosted the speed of its latest range of wireless
LAN products for small businesses to 22 megabits per second, while retaining
compatibility with existing 2.4-GHz systems built to the IEEE 802.11b
standard, the company has announced. 

USR's 22-mbps products will all be available in June, the company said. The
22-mbps Wireless Access Point will have a suggested retail price of $200;
the 22-mbps Wireless Access PC Card, $100; and the 22-mbps Wireless Access
PCI Adapter Card, $120. 

That's a premium of about $20 over the 11-mbps cards already on the market,
acknowledges Juan Lopez, USR's networking product line manager. In some
cases, the price is the same for an 11-mbps card, but "you're not only
getting faster speed, you're getting a stronger radio, better range," he

Old Gear Still Usable
Although a faster alternative, the 54-mbps IEEE 802.11a (also called
Wi-Fi5), has been on the market for over a month, systems based on that
standard are not backward-compatible because they operate in a different
frequency band, 5 GHz, Lopez said. Another competitor, HomeRF, boasts
approximately the same speed as earlier 802.11b products.

But USR's 22-mbps products--a wireless access point or base station, a PC
Card, and a PCI adapter--are fully backward-compatible with existing 802.11b
wireless LAN (WLAN) systems, Lopez said. That means that the new products
can communicate with one another at 22 mbps, and can slow down to 11 mbps to
communicate with older products. 

This backward compatibility with other 2.4-GHz equipment is important, as
many of the service providers offering WLAN coverage in public places such
as airports and hotels are already using 802.11b systems. 

Older gear can still benefit from some of the other performance improvements
offered by the new range. Thanks to a more powerful radio and some other
tweaks, the new products offer 30 percent greater linear range, or about 70
percent better area coverage, than existing systems, Lopez said. 

The three new products use the ACX100 chip from Texas Instruments. In
addition to meeting the existing standard, the chip also supports a new
modulation scheme developed by TI, called packet binary convolutional code
(PBCC). It's this scheme that gives the products the extra kick: Even at
lower speeds, PBCC provides better performance at greater distances, and it
can also work at 22 mbps.

USR doesn't expect to be alone for long in using the ACX100 chip. 

"I suspect you will see more 22-mbps products launched as a result of our
announcement," Lopez said. Other announcements could appear in a matter of
weeks, he said.

For now, TI is the only supporter of the 22-mbps PBCC-22 technology, which
it had hoped to get adopted into yet another high-speed WLAN standard under
discussion at the IEEE, 802.11g. However, the standards committee voted to
use a rival modulation scheme proposed by Intersil, orthogonal frequency
division multiplexing (OFDM), according to TI and Intersil. TI's PBCC-22
remains as an optional part of the still-unfinished standard, which means
products will not have to support it. 

Interoperability Expected
Although no finished standard exists for the 22-mbps WLANs, Lopez is
confident that USR's systems will interoperate with those of its competitors
when they arrive on the market.

"They will all talk to each other at 22 mbps and at all downshift speeds,
since they all use the TI ACX100 chip set," he said. 

The market would probably appreciate that. One of the driving forces of
interoperability in wireless networking, the Wireless Ethernet Compatibility
Alliance (WECA), won't be testing equipment using the new devices for
compatibility at the higher speed, according to spokesperson Brian Grimm. 

WECA typically sets a minimum bar of two chip-set providers and four
implementations before it will test any technology enhancements that come to
market, he said. 

WLANs conforming to the proposed 802.11g will run at up to 54 mbps, just
like 802.11a--but unlike 802.11a, they will be backward-compatible with
existing products, because 802.11g uses the same 2.4-GHz frequency band as

TI has said that when it begins offering 54-mbps 802.11g devices around the
middle of this year, they will also support its PBCC-22 modulation scheme. 

That means, according to Lopez, that USR's 22-mbps products will be able to
operate with its future 802.11g products at 22 mbps, and both will be able
to operate with all existing 802.11b products at 11 mbps.

The average home user will scarcely notice the difference, as cable or DSL
connections typically max out at 1 mbps or 2 mbps. However, in crowded
offices or conference theaters where dozens of users are trying to connect
over the same wireless base station, the benefits of the newer WLAN
technologies will really be felt. 
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