'All fuss but no elan,' analyst says of .11n

Now that draft 802.11n WLAN products are shipping broadly in PCs, market watchers are asking who will use them.

Apple Inc. has announced it is enabling .11n silicon, which the company has been shipping quietly in desktop and notebook computers since late last year. 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. He added, ".11n just does not have the same elan."

Strauss noted that the 100Mbps 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 per second, 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 STBs 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.

Nevertheless, Strauss predicts shipments of 15 million .11n units in 2007, rising to 60 million in 2009, for a four-year CAGR 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.

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

Apple announced in late January that users can download software to activate a draft 802.11n mode in computers that shipped using a chipset configured for .11a/b/g wireless systems. Apple would not say whose chipset it is using in its systems or in new draft .11n base stations it started shipping also in January.

David Carey, principal of Portelligent, said the 20-inch iMac uses a Broadcom BCM4311 Wi-Fi device with a dual (2.4GHz and 5GHz) transceiver. Broadcom describes the chip as an .11a/b/g device. Carey said he assumes Broadcom built in some stealth programmability to support 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 ver 1.10 draft of .11n, including support for 2 x 3 multiple input, multiple output (MIMO) antenna configurations. The Apple .11n implementation will support data rates for TCP/IP traffic of 85-95Mbps. It can handle ranges of 300-500ft, said David Moody, a VP of product marketing at Apple.

Apple will sell software at its online Apple Store for $1.99 to upgrade .11a/b/g systems using a chipset 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.

Bluetooth standard
Apple will not support bonding two 20MHz channels in the 2.4GHz 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 2.4GHz 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.

Just a little ahead of Apple, Intel also announced 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.

Draft 1.10 support
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 20MHz channels together in the 2.4GHz spectrum to achieve higher data rates. The 1.10 draft allows the channel-bonding option if client systems test to make sure the full 40MHz band is available. Hofer said Intel will run additional tests to see whether it wants to support 40MHz channels at 2.4GHz in future versions of its module. The module does support 40MHz channels in the 5GHz band.

The Intel module supports 2 x 3 MIMO antenna configurations, provides sustained 125Mbps data rates and can transfer a 19Mbps high-definition video stream up to 68m. 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/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 1hr more battery life than some competing .11n products. 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.

- Rick Merritt
EE Times