Next-Gen 802.11n Wireless LAN: Failure To Launch?

Now that products supporting the new 100-Mbit/s link are shipping broadly in PCs, market watchers are asking who will use them.

San Jose, Calif. -- Now that draft 802.11n wireless-LAN products are shipping broadly in PCs, market watchers are asking who will use them.

Apple Inc. announced last week that it is enabling .11n silicon, which the company has been shipping quietly in desktop and notebook computers since last fall. The news came on the heels of an announcement from Intel Corp. that it is shipping a draft .11n module that's already being used by such PC makers as Acer, Asus, Gateway and Toshiba.

Despite all the fuss, "we won't see .11n take off like we did .11b and .11g, which was for many people the first way they got on the Internet," said Will Strauss, principal of market watcher Forward Concepts (Tempe, Ariz.). He added, ".11n just does not have the same élan."

Strauss noted that the 100-Mbit/second link will not prove very useful for some time, either in public hotspots or on home networks. "Of all the hotspots in the world, perhaps three use .11n. In any case, all the hotspots limit you to a DSL backhaul" of a few megabits/s, Strauss said.

As for home networks, the great hope for .11n was to become the transport for multiple, often high-definition video streams around the digital home. Those video streams typically originate with a cable or satellite broadcast service, however, and vendors of set-top boxes for those services do not plan to offer native wireless links anytime soon. That's because service providers are concerned that poor-quality video due to interference on wireless nets will create a firestorm of support calls, sapping their profitability and souring customer relationships.

"It will take two or three years for the [home network] scenario to take off" for .11n, said Strauss.

Nevertheless, Strauss predicts shipments of 15 million .11n units in 2007, rising to 60 million in 2009, for a four-year compound annual growth rate of more than 150 percent. In comparison, .11g products shipped in volumes of more than 110 million units last year and had a growth rate of more than 420 percent.

Meanwhile, the PC powers that be are pushing ahead to enable their part of the chicken-and-egg scenario.

Apple said last week that users can now download software to activate a draft 802.11n mode in computers that shipped using a chip set configured for .11a, b and g wireless systems. Apple would not say whose chip set it is using in its systems or in new draft .11n basestations it started shipping last week.

David Carey, principal of Portelligent (Austin, Texas), said the 20-inch iMac uses a Broadcom BCM4311 Wi-Fi device with a dual (2.4-GHz and 5-GHz) transceiver. Broadcom describes the chip as a .11a, b and g device. Carey said he assumes Broadcom built in some stealth programmability to support the draft .11n features. Carey said he suspects the Broadcom BCM4321, which is listed as a draft .11n chip, is probably very similar to the chip Apple has been using.

Apple did say the chip supports the version 1.10 draft of .11n, including support for 2 x 3 MIMO antenna configurations. The Apple .11n implementation will support data rates for TCP/IP traffic of 85 to 95 Mbits/s. It can handle ranges of 300 to 500 feet, said David Moody, a vice president of product marketing at Apple.

Shipping systems
Apple will sell software at its online Apple Store for $1.99 to upgrade .11a, .11b and .11g systems using a chip set that also supports draft .11n. The systems include Intel-based Mac Pro desktops, shipping since August, as well as some Intel Core Duo-based iMacs and MacBooks that began shipping in September.

Apple will not support bonding two 20-MHz channels in the 2.4-GHz band to achieve greater throughput. That's because the broader channels can interfere with Bluetooth, which comes standard on Apple systems. "Bluetooth performance will be so low [under 2.4-GHz channel bonding] that keyboards and mice will not work well enough," said Moody.

Apple developed new utilities for .11n, including a setup tool that lets users create a secure wireless network for both Mac and PC products with a few mouse clicks. Another utility lets a Mac notebook hard drive appear automatically on a desktop Mac once it joins the wireless net.

Weeks ahead of Apple, Intel an- nounced in late January that it is in production with its draft 802.11n wireless modules. In addition, the company has certified four makers of access points as compatible with its chips. Asus, Buffalo, Belkin, D-Link and NetGear will ship .11n access points wearing a new "Connect with Centrino" logo that shows they have been tested with the Intel module.

Intel provided no details about whether the largest notebook makers--Dell, Lenovo and Hewlett-Packard--will use its .11n modules. Linksys, a subsidiary of Cisco Systems Inc., is "evaluating" the Intel interoperability program for access points, said Dave Hofer, director of wireless marketing for Intel's mobile-platforms group.

Intel claims its .11n module complies with the IEEE 1.10 draft issued at a meeting in London in January. However, the module's initial version will not support bonding two 20-MHz channels together in the 2.4-GHz spectrum to achieve higher data rates. The 1.10 draft allows the channel-bonding option if client systems test to make sure the full 40-MHz band is available. Hofer said Intel will run additional tests to see whether it wants to support 40-MHz channels at 2.4 GHz in future versions of its module. The module does support 40-MHz channels in the 5-GHz band.

The Intel module supports 2 x 3 MIMO antenna configurations, provides sustained 125-Mbit/s data rates and can transfer a 19-Mbit/s high-definition video stream up to 68 meters. It includes four chips--two analog front-end devices believed to come from third parties and an RFIC and baseband made by Intel.

Intel's 4965AGN module supports twice the range and five times the throughput of the company's current .11a, b and g module, Hofer said. In addition, he said, ".11n will support whole-home coverage with the ability to handle high-definition video."

The module delivers up to one hour more of battery life than some competing .11n products, Hofer said. However, the company did not provide details about exact power consumption.

Intel supports the plans announced last August by the Wi-Fi Alliance to certify draft .11n products, Hofer said, while the Connect with Centrino program adds other tests. "We view the WFA as testing protocol-level interoperability. We add real-world test cases the WFA does not test for," he said. Specifically, Intel has tested interference with microwave ovens, baby monitors and cordless phones.

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