An article published here on Wednesday, which argues that the Wi-Fi Alliance is stifling faster wireless networking, has provoked a strong reaction.

The Wi-Fi Alliance has threatened to refuse (or withdraw) certification for products with "pre-802.11n" speed enhancements, if they impact interoperability with existing products. Ira Brodsky, president of market research company DataComm Research, said here that this stance will dissuade vendors from offering faster products and result in less innovation.

This argument has been slammed as "specious" by Glenn Fleishman of Wi-Fi Networking News, who argues that vendors are perfectly free to make innovations but shouldn't expect certification for products that fall outside that standard.

Faster devices are good, but users should be aware of likely compatibility problems, says Fleishman: "Don’t come crying to the Wi-Fi Alliance when your non-Wi-Fi branded (or Wi-Fi certification pulled) pre-N, pre-X, pre-Y, and pre-Z equipment interferes with the operation of your Wi-Fi networks. As individual consumers or businesses, you can make the choice for speed or features over compatibility."

The fact is, he points out, that non-standard equipment only works faster if you get all your kit from one vendor, and this lock-in is the price you pay for higher speed. The Wi-Fi brand is about compatibility, so of course it should not be given to non-compatible kit.

802.11g - not such a good example
Brodsky gives the example of 802.11g products arriving before the IEEE had ratified a final standard. Bad example, says Fleishman: "802.11g’s early rollout was almost a disaster. Firmware was changing constantly. Equipment using the same chipsets often didn’t work correctly among devices from different vendors and performance glitches could make networks slower with 802.11g than with just 802.11b."

Certification by the Alliance eventually settled 802.11g products down.

After 802.11g was standardised, there have been extensions to 802.11g (see G Whizz - the 802.11g boosters) but these mostly work if you get equipment from one manufacturer. "If you want 40 Mbit/s, then you have to buy all from one maker," says Fleishman. "For 20 Mbit/s, you can use any 802.11g" (read our comparison of actual speeds against claims).

Among these extensions, a conflict arose between Atheros and Broadcom, which has apparently not been resolved: "Atheros’s products use a dual-channel bonding that Broadcom claims can cause disruption and lower speeds on nearby networks," says Fleishman. Atheros claimed not to see the problem with its Turbo mode, but its OEMs have implemented their products to only use dual bonding if there are no non-Turbo mode clients around.

MIMO products are a red herring?
Brodsky isn't talking about these older speed-boosters, however. He is talking about newer MIMO-based products (what's MIMO? Read this), which don't seem to cause problems. "Far from disrupting current Wi-Fi products, MIMO-OFDM products offered by vendors such as Belkin and SOHOware are Wi-Fi-certified and boost performance when used with 802.11a/b/g products," said Brodsky.

Our Belkin Pre-N review bears this claim out but it's a red herring, says Fleishman: "These enhancements are only well-behaved by accident."

The Pre-N products from Belkin and others are indeed Wi-Fi certified, he agrees, but they are not certified in the pre-n modes - and nor should they be. They are only certified in their 802.11b/g modes.

It is perhaps surprising that these MIMO products allow better range and throughput, even when working in 802.11g mode with existing 802.11g adapters. But that is just a matter of luck, says Fleishman. MIMO involves smarter antennas, which are better at picking signals out of the air - even non-MIMO signals.

But the Alliance doesn't stop you selling products!
Witholding Wi-Fi certification will make users wait three years for faster Wi-Fi, says Brodsky. No it won't, says Fleishman: "Companies can release all the pre-N they want, but they can’t necessarily call it Wi-Fi."

The Wi-Fi Alliance doesn't prevent products coming to market, says Fleishman. Its label is only for products that work with other labelled products. Products with a Wi-Fi Alliance brand must not cause problems when working with other branded products and that is all.

"The Alliance doesn’t exist to protect vendors’ right to innovate," says Fleishman. "It exists to protect its members’ ability to use a brand that has a strong promise to consumers and business IT: that anything labelled Wi-Fi interoperates with anything else labelled Wi-Fi."

Deliberately confusing?
Fleishman is right, of course. Brodsky's article (deliberately?) confuses products, with their modes of communication.

One product can communicate in different modes. It can be certified for 802.11a/b/g, but also offer a faster mode, which isn't certified. This is as it should be. The Alliance has not threatened to take away 802.11a/b/g certification from products whose pre-n communication is well behaved.

Brodsky is probably right to think that losing Wi-Fi certification would affect sales of a Pre-N product. But what is the alternative? Is he suggesting the Alliance should certify the faster mode, before an 802.11n standard exists to certify it against? Or that products should keep their a/b/g certification, even if their Pre-N mode interferes with certified a/b/g communications? Either would make no sense.

If nothing else, the argument shows that the Alliance's certification is considered to be valuable. That value will be maintained, if the Alliance takes the same approach to pre-n products, that it has for earlier generations of Wi-Fi.

Read Glenn Fleishman's full response here.