Chip Company Says Competitor Cripples WLANs

By Ed Sutherland

November 17, 2003

UPDATED: The gloves are off as the 802.11-product chip makers let fly with accusations that a proprietary speed-boost from channel bonding may cause the speed of existing 802.11 networks to drop.

Broadcom , a leading maker of 802.11g chips for wireless devices, plans to use this week's Comdex trade show in Las Vegas to back up charges a competitor's Wi-Fi chips could interfere with nearby 802.11 networks.

Broadcom is alleging the 108Mbps 'turbo' mode of Atheros Communications' 802.11g chips using Super G cause "enormous degradation" of nearby 802.11b and 11g connections. The company says it will demonstrate the supposed problem this week.

Atheros denies the allegation.

The charges are "fairly contrived," says Sheung Li, Atheros Product Manager. "They (Broadcom) are showing something common to all 11g products," he says.

Li says Broadcom's allegations are based on results from a powerful and confined network where radios are within 100 feet of each other.

Li says "it is kinda funny" Broadcom points only to the 'turbo' aspect of SuperG, thereby giving tacit approval to the rest of the standard. It is "absolutely false" that SuperG is not a "good neighbor" with other Wi-Fi devices, he adds.

D-Link and Netgear both have 108Mbps wireless products out now using Super-G. Neither company have complained to Atheros of interoperability problems.

The problem, according to Broadcom, is that the 108Mbps turbo mode employs -- among other methods such as frame-bursting and compression -- two channels bonded to gain the added speed boost. This can interfere with nearby signals and slow wireless networks, getting as low as 1Mbps. "We've found out what others will soon discover," says Jeff Abramowitz, WLAN marketing director for Broadcom.

The result would be Super G-based products could only talk with Super-G gadgets, according to Broadcom.

Broadcom denies it is singling out Atheros.

"We really are not specifically targeting Atheros or going after them, per se," says company spokesman Henry Rael. "Rather, we would like to call attention to any technology that can be harmful to the continued growth of the industry," he said. The Broadcom official calls the inteference and interoperability issues a "speed bump" in the continued growth of Wi-Fi products.

Abramowitz says he was surprised over the attention the allegations are receiving. "Our plan wasn't to make this a media event," he says.

Broadcom would like to see either a disclaimer on 108Mbps gear sold to consumers or a more standards-based approach by Atheros. In the end, Abramowitz says the issue will effect few beyond first-time wireless consumers comparing a box labelled 54Mbps and one marked 108Mbps.

"This is a retail issue," says Abramowitz.

An Atheros spokesperson says the company will be at Comdex and looks forward to hearing Broadcom's explanation of the possible interference.

Julie Ask, analyst for Jupiter Research, believes the allegations are a sign the Wi-Fi chipmakers are attempting to break from the pack.

"I think it's inevitable that companies will look for ways to differentiate their products by adding features, stretching the bounds of the standards, and through proprietary offerings such as Atheros," she says.

Ask says there is still a need for cooperation among Wi-Fi devices.

"Given that this is an unlicensed band, there has to be a good neighbor policy. I think anyone who buys 'non-standard' products is at risk of interoperability issues," she said.

The Wi-Fi Alliance, which grants certification to Wi-Fi products after testing them for interoperability, says it could repeal the group's approval if gear does not interoperate or cooperate with existing wireless devices.

While the D-Link product has received certification, the Wi-Fi Alliance has not given the green light to the Super G standard.

D-Link's XtremeG 802.11g card was granted Wi-Fi certification earlier. The company says its 108mbps gear generates interference only found normally between Wi-Fi devices.

Broadcom customers, such as Buffalo Technology and Apple, can't get a 'double speed' boost like the Atheros Super G. Broadcom does, however, offer a speed enhancement called Xpress that is based on the frame-bursting that will be present in the eventual 802.11e standard.

Broadcom is also showing a new technology at the show this week called InConcert, which is says lets technology like Wi-Fi and Bluetooth coexist even tho they use the same frequency range.



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