Wireless LAN chipmaker Atheros Communications
of Sunnyvale, Calif., has taken the wraps off its third generation of product
silicon for wireless networks. The company’s first generation was all 802.11a;
the second was a three-chip set for 11a or dual-band 11a/g, which is currently
in use in clients from most of the major retail vendors such as Linksys and
Now the company is coming out with a complete suite of chips, some specific
to clients with another set for access points or routers/gateways.
Craig Barratt, CEO and president of the company told 802.11 Planet that
the key aspect of this latest generation of chips is that "all are two-chip
solutions." Previous dual-band solutions from the company used two radios,
but they now offer a single radio chip. With that, "cost is lower and the
performance is improved," he says.
Barratt sees the market as three distinct segments Atheros can target: dual-band
(802.11abg) is for the enterprise, 802.11g (with backwards compatibility to
11b) only is for home networks, and the high-bandwidth of 802.11a by itself
is best for multimedia use.
Atheros has always been a big proponent of 802.11a,
since it started with that standard — the company often denigrated early
802.11g products as substandard. Barratt says that activity in the middle
part of the 5GHz radio frequency band used by 802.11a is likely to grow in the
United States over the next year as the middle part of the band, 5.470 to 5.725
GHz, which is in use in some overseas countries but not the U.S., may become
available. When that happens, 802.11a will get access to 27 total channels,
instead of the 16 it gets here today. The Federal Communications Commission
(FCC) is in the process of finalizing rules for that
band, a move introduced in the Jumpstart Broadband
Act. Ballard says this change would mean a "bigger and bigger footprint
coming available at 5GHz." If it happens, Atheros-based products will support
it with a driver upgrade (Atheros’s first generation chips would not support
the new ranges, they only work in the lowest available, 5.15 to 5.35GHz).
When it comes to client systems, Barratt says users should be able to pick
up any dual-band card they want and not feel tied to the same manufacturer as
the infrastructure products they use. "What we want to do is disconnect
the notion of a choice of a client from the choice of the access point. People
tend to purchase in pairs — get an 11b access point, thus get an 11b card.
People think if they get 802.11abg card, they need a/b/g access point. That’s
a misconception we’re trying to correct."
The Atheros chips for access points are complete system on a chip (Soc) solutions
which include the AR5002AP-2X for dual-band coverage with simultaneous 802.11a
and 802.11b/g coverage; the AR5002AP-X support for 802.11a or 11b/g but only
one at a time, the 11b/g only AR5002AP-G, and the 11a only AR5002AP-A. The 11a
SoC supports Quality of Service
802.11e specification to improve multimedia performance.
On the client side, the chips include the 11abg AR5002X which can self-configure
to chose right frequency of the network, the 11b/g only AR5002G, and the 11a
only AR5002A (again with QoS support). All have dynamic frequency selection
(DFS) and transmit power control (TPC) capabilities.
All the chips will ship with support for Wi-Fi Protected
Access (WPA), Temporal Key Integrity Protocol (TKIP), and can upgrade to
802.11i when it’s done (AES encryption, required for 802.11i security, is built
in.) Those using 802.11g will ship with support for the latest draft of the
specification, which is expected to be ratified by the IEEE
All of the chips also support Atheros’s recently announced "Super G"
and "Super A/G," which uses a mixture of signal bursting, compression,
and other optimizations to get speeds Atheros says can reach 90 Megabits per
second in real-world throughput (most 802.11a or 11g networks top out in the
mid-20s of Mbps.) The "Super" speeds also require use of the (theoretical)
108Mbps Turbo Mode unique to Atheros-based products. With these new chipsets,
Atheros has made Turbo Mode automatic.
"Bursting is compatible with other chipsets, but the remaining features
are only enabled when we auto detect our chips on both ends of the link,"
says Barratt. "Turbo mode was once static, turned on once. Now it’s dynamic.
It’s automatically switched on when Atheros devices are on.
Barratt says the chips are all in full production and they already have in
excess of forty design wins with equipment manufacturers. He expects the first
products with the new chips will be available in stores in July.