Thursday, August 31, 2006

WiFi 802.11n is Leaving The Station

All aboard the 802.11n train. We're leaving the station now. Don't be left behind.

After years of wrangling over the precise technical definition of the enhanced bandwidth version of WiFi, the Wi-Fi Alliance has announced that it will begin certification of 802.11n hardware beginning in March, 2007.

Wow, that means the IEEE 802.11n standard must be finished and approved. Well, not exactly. The IEEE or Institute of Electrical and Electronics Engineers is planning to ratify its standard in the early part of 2008, not 2007. So, what gives? Did someone not synchronize calendars?

Actually, this is more like we're leaving the station and we'll get the maps later. Why? Because the passengers are getting restless and making other transportation arrangements.

The WiFi upgrade from the currently popular "g" standard is intended to boost throughput from a maximum of 54 Mbps and typically 20 - 25 Mbps, to a typical 100 Mbps with a maximum of at least 200 Mbps and perhaps much more as the technology matures. Just as important, 802.11n will result in greater range for typical users. The MIMO (Multiple Input / Multiple Output) smart antenna technology thrives on the kind of multipath interference found in indoor environments, where the radio waves bounce off furniture and walls. As a result, a MIMO based wireless network will have higher speeds at greater ranges indoors, and even outdoors.

Why the need for speed? There are a couple of drivers. In the office and factory environment, having even a bandwidth of 30 Mbps throughout the building enables wireless roaming for nearly all business applications. Fast database access, large file downloads, high resolution graphics and even full motion video are feasible. In the SOHO (Small Office / Home Office) environment, MIMO eliminates dead spots and provides whole house or office coverage. The higher bandwidths aren't needed for email or Web browsing, but are useful for wireless video playback.

The desire to unplug from wired networks and achieve wireless networks that operate reliably encouraged manufactures to offer "Pre-N" products even a year or more ago. These devices consist of wireless access points and routers plus compatible plug-in cards for laptop computers. Some of these Pre-N offerings are so "pre" that they will probably wind up being proprietary products with no upgrade paths.

So why go out and buy something that may be obsolete when 802.11n is released? The risk is mitigated by compatibility between the Pre-N equipment and the current "b" and "g" standards. The official "n" release will also be compatible with the earlier standards. So, worst case you have a network that won't live up to the performance standards of tomorrow but you get compatibility with WiFi equipment today and improved speed and range among compatible "Pre-N" devices. The whole standards process is on such a long term schedule that some companies figure their "Pre-N" equipment may be ready for replacement by the time 802.11n is ratified.

Apparently the potential rewards have begun to overpower the perceived risks to such an extent that the trickle of migration to "Pre-N" networks is turning into a flood. That, and the solidification of the future 802.11n standard is what is prompting the Wi-Fi Alliance to kick off the testing and approval cycle a year early. That approval isn't a guarantee of compatibility with the final standard, of course. But it does provide a big boost of confidence for the industry moving into Wireless-N network upgrades.

Any remaining doubts that the MIMO train is leaving the station? No less than Intel has said that it will upgrade it's Centrino product line to include compatibility with 802.11 a/b/g/n in the first half of 2007. Once those chips start showing up in laptop and notebook computers, there will be no stopping Wireless-N.

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