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April 12, 2007 Provided by System Dynamics Inc.

"Draft 802.11n"--On Track for Wi-Fi Certification

After many delays and confusing product claims, IEEE 802.11n--the next generation of Wi-Fi--now seems to be heading solidly in the right direction. IEEE Task Group 802.11n ( ) and the Wi-Fi Alliance have set a common path toward an agreed standard and interoperability testing. Although scheduled publication of the final standard is still more than a year away, certified interoperable products are expected to reach the market this summer. This should end the consumer confusion caused by the many incompatible "draft n" devices that flooded the market last year.

For those who have not been following the story, 802.11n promises 100 Mbps throughput--4 to 5 times faster than the real-world throughput of its predecessors 802.11a and 802.11g. 11n gets higher throughput by running at higher data rates, combining several 20 MHz channels, and concatenating packets to cut down on dead air time. It gets greater range by using MIMO "smart antenna" technology to overcome multipath distortion. It supports both the 2.4 GHz spectrum used by 802.11g and the 5 GHz spectrum used by 802.11a, and is backward-compatible to simplify migration.


When the IEEE 802.11n Task Group started its standards-making efforts in September of 2003, the projected publication date was October 2005. Two years ago, the date had slipped to early 2007. Now it is October 2008.

IEEE standards efforts are often slowed down by vendor infighting and factionalization, with vendors promoting specific approaches that leverage their intellectual property. The IEEE standards process requires a 75% affirmative vote to approve each drafting stage; in the absence of broad consensus, any individual faction rarely has enough support to reach the 75% affirmative votes required to go forward, but can often rally the 25% negative votes required to block other factions. Factionalization has sometimes killed a standard--we wrote last year ( ) about the demise of IEEE 802.15.3a, which was attempting to set a standard for UWB. In 802.11n, the factions have jockeyed for years without being able to bring a draft to a affirmative ballot.

In mid-2005, one large faction got together outside the IEEE meetings ( ), put together a proposal of their own, started shipping chips loosely based on it, and submitted their proposal to the IEEE task group as a proposed draft for 802.11n. By early 2006, many equipment vendors were selling so-called "draft n" products based on those chips. As we wrote last June ( ), these products did not work well with each other, and some were not "good neighbors" to nearby 802.11b and 802.11g networks. One of the most respected reviewers wrote "The industry had better stop hyping and start fixing this crap...and fast."

The Wi-Fi Alliance (WFA)--the certification and marketing side of the Wi-Fi juggernaut--looked with dismay at these negative reviews. WFA had long declared that it would not certify 802.11n products until the finished standard was published. But with market confusion over the "draft n" products, and little sign of the IEEE process moving toward convergence, WFA reversed its position. In an announcement last August ( ), WFA said it would "certify interoperability of Wi-Fi products that include baseline features from the developing IEEE 802.11n standard in the first half of 2007" and that after publication it would certify standards-compliant products to bring "full alignment with the ratified standard". To avoid confusing consumers, WFA said "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 announcement raised the question of which draft would become the basis for pre-standard testing. Late last year, we were told that although the Alliance preferred to base its certification program on an approved draft, it had made it clear that it would stick to its announced "first half" timetable and proceed with certification based on a working draft, whether or not that draft had achieved the required 75% affirmative vote.

The WFA announcement shifted the center of gravity of 802.11n development. Most companies seem to have decided that Wi-Fi certification will be necessary to clarify the marketplace confusion, and moved quickly to ready chips and products for the certification program. At CES in January, many companies told us they would soon ship chips and devices that were "on track" for certification, and expected that these devices would be software upgradable to conform with the "pre-standard certification" tests. Some of these devices have already reached the market; many more are expected in the next few months.

The IEEE group seems to have paid attention--the 802.11n drafting process quickly converged. In February, Draft 1.10 passed with 98% affirmative, setting the stage for the long-awaited Draft 2.0. This passed a few weeks ago with 83% affirmative. The projected publication date is still more than a year away, but hopefully will now remain stable.

We recently talked on the telephone with Karen Hanley, WFA's Senior Marketing Director. She confirmed that the WFA program is "on track" and that as planned there will be a "second phase" when the final standard is published next year. She said WFA expects that "the bulk of equipment in 2007 will go to consumers. The program will be one of our largest uptakes" and there might be "1 to 15 million end products in 2007." She said WFA expects enterprises will mostly wait for second-phase products, although those for which "range is important" might adopt the early products.

We asked Karen whether these first-phase products were likely to be upgradeable to the final standard; she said "that would be up to the individual vendor."

Intel's "Connect with Centrino" Program

In late January, we received an announcement from Buffalo Technology saying that Buffalo had "joined Intel's 'Connect with Centrino' program" and that its "AirStation Wireless–N Nfiniti Dual Band Router & AP is fully interoperable with any dual-band Centrino Mobile Technology notebook with Intel Next-Gen Wireless-N technology." That seemed like an interesting twist on the certification question, so we followed up with Buffalo and Intel.

A few days later, we talked on the telephone with Mark Grodinsky and Ashish Gupta, both product managers in Intel's wireless group. Mark started by reassuring us that Intel's program was complementary to the WFA certification program. He said that as chair of the marketing task group of WFA, 11n certification is under him. "I used to work for Frank [Hanzlik-WFA's Managing Director] way back. He is very comfortable with what Intel is doing. WFA is responsible for interoperability - making sure the products interoperate. Intel wants to be sure that Centrino notebooks equipped with Intel Next-Gen Wireless-N will work with other devices you buy.

"It's more that just interoperability. We start with interoperability and test to make sure all devices interoperate. Then we go to the next level. We have a 4200 square foot home and an office environment. We use real-world functionality scenarios. We test usage models, obstructions, and interferers. The whole point is to make it complementary to WFA.

"Devices will have a logo on the box. Customers will be able to buy logoed products in early February from Netgear, Buffalo and others.

"The Wi-Fi logo says it will work with other products with the Wi-Fi logo. 'Connect with Centrino' will assure a good experience for users, analogous to 'Verified for Centrino' hotspots."

We just looked at Buffalo's website, and sure enough, the WZR-AG300NH Dual Band Gigabit Router & Access Point is available.

And it sports the "Connect with Centrino" logo.

For further reference:

  • See Wireless Networking--Is "Draft n" Too Early? ( ) (BBHR 6-19-2006) for more on IEEE 802.11n and early "draft n" products
  • See our topical guide to wireless networking ( ) for our reporting on 802.11 and Wi-Fi

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