802.1n promises wireless local area networking at speeds in excess of 300Mbps. The draft standard was released in January 2006  and since then several major manufacturers including Linksys, D-Link and NetGear have introduced products conforming to the draft and Dell has announced plans to ship laptops with draft 802.11n wireless in-built .

However, on latest estimates the standard will not be finalised until 2008  and there have been suggestions that these draft products will not be upgradeable and, more importantly, claims that they create interference to nearby networks operating on the current 802.11g standard.

Linksys has responded to the criticism by announcing that it has tested its draft 802.11n products for backward compatibility with 802.11n equipment form several other manufacturers. However it has not tested interoperability with other draft 802.11n products.

Two of the leading producers of draft 802.11n chips, Atheros and Broadcom, claim to have tested their products for interoperability. However, they noted that the 802.11n specification contains a large number of mandatory and optional features. "Interoperability is not trivial due to the complexity of the standard as well as the number of mandatory elements. It is particularly important that devices support the mandatory elements as their presence is assumed by other vendors, and omitting them can prevent interoperability between vendors." They tested only six of the mandatory elements!

The Wi-Fi Alliance has not detailed how many features will be covered by its interoperability testing and certification programme, saying only that that it will include "baseline features from the developing IEEE 802.11n standard".  It adds that "This is the first phase in a certification program of [802.11n] products. A second phase brings full alignment with the ratified standard."

The Alliance justified its two-phase approach to certification in light of analysts forecast that tens of millions of pre-standard devices will ship in 2007. These could include those conforming to the draft and others that use proprietary techniques."While we are committed to supporting a full 802.11n standard when it is available, pre-standard products are reaching a level of maturity and there is enough market uptake that a certification program makes sense for the industry," said Wi-Fi Alliance managing director Frank Hanzlik.

The Alliance has also sought to diminish concerns that current draft products will not be compatible with the final standard.  It will introduce a its second phase interoperability testing and certification when the 802.11n standard is finalised and expects this  "will support compatibility between Wi-Fi certified pre-standard products and those certified to the full standard."

It seems highly likely that by 2008 with pre-n (ie those that came out even before the draft was released) and draft-n (current products) that are not Wi-Fi certified on the market along with Wi-Fi certified draft-n and certified 'final-n' products consumers will be highly confused (these products are, after all aimed at the consumer as well as the business market).

Hanzlik however claims otherwise "The certification marks used for the first phase of the program will clearly indicate that the certified products are pre-standard, so that consumers will understand that what they are purchasing is not based on a ratified IEEE standard."

The Alliance says  it will announce details of the program name when it is finalised.