The proposed IEEE 802.11n wireless-LAN standard failed to progress in a vote earlier this week. The opposing factions in the IEEE's 11n task force immediately stated opposing interpretations of the nature of the setback.

According to Airgo, the lack of support means the group's members recognise the "desire for significant changes to the draft." But rival chipmaker Atheros Communications asserted, "A 'no' vote at this stage does not indicate that there will be radical change to the standard."

Both at least agree that the standard remains on track for final ratification by the IEEE in mid-2007.

The Draft 1.0 document was accepted by the 11n group in March by a 87 percent majority vote. Then the task group began accepting comments and recommendations for changes. This week, according to Airgo, only 46 percent voted in favour of moving the draft to the next step of the review process.

Procedurally, the vote has little effect on the current work of actually studying the submitted comments and figuring what should be done about them. But the efforts to influence how people view the emerging standard show how much the chip vendors have at stake.

Airgo was the first company to introduce a commercial radio chipset that uses Mimo (multiple-input multiple-output) technology. That silicon is now in its third generation. Wireless-LAN vendors such as Belkin, Linksys and Netgear have access points based on the Airgo chips, aimed at the home and SOHO markets. But Bluesocket and Taiwan-based laptop OEM Asusa have just announced, respectively, an enterprise access point and a wireless high-end laptop that use Airgo's third-generation chip.

Airgo has a huge lead over rivals such as Atheros, Broadcom and Marvell. All three announced their first Mimo chipsets when the 11n draft was adopted. All three describe their silicon as being compliant with the draft 11n specification.

But the first products based on these early rival chips are being received with tepid reviews. A benchmark test of five Mimo products in a rented home, performed by wireless consultancy The Farpoint Group found that the Airgo-based Linksys SRX400 access point delivered higher throughput over longer distances than four other products, one using Marvell silicon, the other three (including another Linksys product) using Broadcom.

Interoperability among the various brands of access points and client cards was also disappointing, according to Farpoint Principal Craig Mathias. "In no case could we get any heterogeneous combination of the 'draft compliant' clients and [wireless] routers to connect at more than typical 11g (20-24Mbps) rates," he wrote in the test report.

"While we were not surprised with the obvious immaturity of the 'draft compliant' products, our expectations were frankly higher. Range-vs-throughput performance was relatively poor, security implementations need work, and the interoperability implied by [the term] 'draft compliant' seems to be missing."