Tests confirm Atheros' Super G degrades rival WLANs

But Broadcom has nothing to smile about...

Broadcom's allegation that 802.11g Wi-Fi products based on chips developed by its rival, Atheros, will degrade the performance of nearby wireless networks appears to have been verified by independent tests.

Tim Higgins of web site Small Net Builder carried out a comprehensive series of tests to see if
Atheros' Super G technology, which promises to double the range of WLANs built out of Atheros kit, interferes with adjacent networks not based upon the technology.

And that's what he found: "A Super G wireless LAN running at full speed will interfere with an 11g WLAN also running at full speed. Severe throughput loss in the 11g WLAN can occur up to 30 feet away and significant throughput loss may still be seen around 50 feet."

Higgins tested the throughput of a variety of WLANs, following it up with an attempt to replicate the findings Broadcom showed at Comdex last month, specifically degradation to streaming video throughput.

"A Super G WLAN running at full speed will seriously interfere with an 11g WLAN running streaming video even at 30 feet," he concludes. "But the interference is essentially gone at 50 feet."

Naturally enough, Broadcom is cock-a-hoop with Higgins' findings, and put out a statement t'other week agreeing with his initial. However, the results of the independent tests aren't so clear cut, and Higgins updated his article a few days later with some further information.

Higgins followed up his Broadcom vs. Atheros tests with further work that pitched Atheros kit against product based on other Wi-Fi chip-makers product. The result: there is interference, but not as near as much as the Broadcom products suffered from.

Higgins revised the two conclusions we've quoted above from "interfere with an 11g WLAN" to "interfere with some 11g WLANs".

"Super G Interoperability problems appear to be most severe with Broadcom-based 802.11g products," he writes. "Dynamic Super G-based wireless LANs do not interfere with all 802.11g and 802.11b wireless LANs operating on Channels 1 or 11, even at ranges under 10 feet."

The bottom line is that not everyone will experience problems if their WLAN happens to exist alongside one based on Atheros kit with Super G enabled. However, as the initial results show, there is at some level a degree of degradation. Atheros has a duty to respond to the Broadcom claim rather than just deny it, as it has in the past. But Broadcom needs to ask itself why its own products are more susceptible to interference that others'.

Of course, part of the problem here, as Higgins himself notes, is the highly competitive nature of the business. It's that that is forcing vendors to bolt on proprietary technologies like Super G in order to differentiate their products. The question is, in a market that has grown because of the interoperability that adherence to a standard ensures, is there a place for non-standard technology?

Arguably there is, but it should not be discussed in the same breathe that's used to talk about compatibility. Just because access point A can run at 108Mbps doesn't mean access point B will. But less well-informed punters may assume it does. Techies are smart enough to know that the boosting technology 'busts' the standard, and can buy accordingly to gain the maximum throughput, but many consumers and business buyers may not be so savvy.

Higgins' follow-up test report can be read here. Part one is here.

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