802.11n will triple throughput of WLan

The Institute of Electrical and Electronics Engineers (IEEE) will begin sifting through a record number of proposals for a...

The Institute of Electrical and Electronics Engineers (IEEE) will begin sifting through a record number of proposals for a high-speed amendment to the 802.11 standard next week, but wireless chip makers are already jumping the gun with pre-standard products.

802.11n is intended to more than triple the real throughput of wireless Lan (WLan) by focussing on enhancements to the MAC (media access control) interface, rather than the physical layer. This should mean the real throughput more closely matches the theoretical maximum rate.

Currently the fastest WLan gear has a real-world limit of 30Mbps, which the "n" standard will push up to at least 100mbps.

As with 802.11b and 802.11g, initial demand is being driven by an insatiable US consumer market for applications such as wireless video transfer in the home, but the higher bandwidth is expected to benefit enterprise applications such as voice over IP (VoIP).

"Quality of service is absolutely more important than sheer bandwidth [for VoIP], but more bandwidth never hurts," said Dean Bubley, founder of Disruptive Analysis. "For one thing it makes QoS work better if there's lots of headroom."

With the proliferation of wireless devices in the office, 802.11n could also combat network congestion.

"With wireless, the bandwidth is contended between multiple devices on the same access point. You don't necessarily need 200mbps to each individual device, it is shared amongst users in the enterprise or on a hotspot."

The 802.11n task group will begin to pick and choose among the 61 proposals submitted since the mid-January call for entries. The process is likely to be tortuous, with big players such as Atheros Communications, Broadcom, Intel, Sony and Texas Instruments reportedly lined up in opposing camps, and a finished standard is not expected until 2005 or 2006.

The standards body will not have time to sit on its hands, however, with suppliers including Broadcom and Airgo Networks jumping to release proprietary products that use the technology they have submitted to the 802.11n group.

Airgo said it had signed up four customers to its True Mimo smart-antenna technology, with two, SOHOware and Planex Communications already shipping True Mimo-based products that are backward-compatible with existing 802.11 standards.

Airgo claims the popularity of its technology in the marketplace will ensure it becomes a cornerstone of the as-yet-non-existent standard.

"Progress commercializing Mimo technology is leading the industry to adopt the technology for 802.11n," said Gartner semiconductor analyst Joseph Byrne.

Broadcom, which successfully marketed pre-standard 802.11g chips, said in January that it was planning to sample 802.11n chips this year, but the company later said it would wait for the IEEE.

Pre-standard equipment carries the risk of interoperability problems, but consumers are not as sensitive to this issue as businesses, according to analysts.

"Without market demand to speed it up, standards processes can go on for a long time," said analyst Robin Duke-Woolley of E-Principles. "There is a need for proprietary products to drive the market."

The stakes are high for 802.11n, partly because other 802.11 "Wi-Fi" technologies are already so popular - it is easier for users to upgrade to a new Wi-Fi flavour than to switch to a new technology such as Ultrawideband.

802.11n is likely to push Ultrawideband out of consumer electronics for all but a few niche uses, according to a report by ABI Research last week.

The 802.11i specification for improving WLan security was approved last week, and a host of other WLan standards are also on the way. Among them are "e", for quality of service, "r", for improvements to roaming between networks, and "f", for defining how access points interact.

Matthew Broersma writes for Techworld.com

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