Columnists

Draft 802.11n Wi-Fi networks move to mainstream

I have some concerns about the draft-n technology and, for that matter, about products that meet the final standard, which are due to debut late this year.

By Maury Wright, Editorial Director -- EDN, 5/10/2007

The tumultuous IEEE 802.11n wireless-LAN-standards process is still months from completion, and the infighting among major players has been worse than in most standards bodies. More than two years ago, Airgo Networks (now part of Qualcomm ) began shipping what some labeled pre-n products (see "Pre-n arrives"). Now, a host of semiconductor vendors has driven "draft-n-complaint" products to market. I've been negative on both the infighting in the standards body and the premature product announcements. But the draft-n products do deliver improved data rates and range. Moreover, it appears that, in this case, the Wi-Fi Alliance certification of products coming in June may be more important than the work of the 802.11n committee.

"I believe it's the Wi-Fi logo that gives consumers confidence," says Bill Bunch, director of product management for wireless LANs at Broadcom. He is correct that consumers want products that interoperate. Bunch claims that users will be able to upgrade all of the products Broadcom has shipped with the draft-n label to the ultimate standard and that they will comply with the Wi-Fi Alliance certification process.

Broadcom currently leads in draft-n IC shipments—a bit ironic given that Broadcom was a late comer to what became the EWC (Enhanced Wireless Consortium), which Intel and Atheros formed to speed the technology to market (see "802.11n progress: standards building or end run?"). You can believe the Intel and Atheros spin that they were working in the best interest of the industry in accelerating the deployment of new technology or that they were trying to gain an advantage by defining the technology in their own way. In either case, Broadcom had been at odds with that duo priot to joining the EWC.

As a user and observer, I'm eager for the technology to hit the market. The new network will enable cool applications, such as video distribution, and even drive demand for more bits from the core networks. For almost two years, I've enjoyed the speed and range advantages of several Airgo-based products. Those products have been 802.11g extenders because they interoperate with products from other vendors based on backward compatibility only with 802.11g and even 802.11b. The Wi-Fi-certified draft-n products should offer interoperability among vendors with the greater data rates that the new standard offers.

Still, I have some concerns about the draft-n technology and, for that matter, about products that meet the final standard, which are due to debut late this year. All of the 802.11 wireless standards have had options. Manufacturers have been able to skip support of some features to cut costs. The 802.11n technology will be the worst yet. Unlike previous standards, 802.11n defines operation in both the 2.4- and the 5-GHz frequency bands. But the standard does not require manufacturers to implement support for both bands, and most of the draft-n products that vendors are now shipping to consumers support only 2.4-GHz operation.

The 2.4-GHz band has so far served us well, but it's increasingly crowded. Apple supports both bands in the draft-n implementation in the company's new Apple TV. As Broadcom's Bunch points out, the 5-GHz band provides 24 additional nonoverlapping channels, whereas the 2.4-GHz band supports only three such channels. Apple likely wanted to ensure that the TV product would find a channel without interference from other Wi-Fi traffic or other products, such as cordless phones.

Bunch claims that Dell, Acer, Lenovo, Apple, and Hewlett-Packard have all designed notebooks with 5-GHz-capable 802.11n implementations. For now, however, you won't likely find an access point that supports the 5-GHz band. So, even if you have a spiffy new, 5-GHz-capable notebook and a similarly capable Apple TV, your access point may prohibit operation in the higher band.

Bunch believes that situation will change as the technology matures and costs come down. He points out that dual-band support in a client is much easier and less expensive than dual-band support in an access point. In a client, only one radio operates at any given time. An access point must simultaneously support both bands. All of these scenarios make perfect sense except to the consumer who brings home a bag of Wi-Fi-certified products yet can't take full advantage of the technology.