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Senior U.S. Correspondent

Industry group agrees on high-speed Wi-Fi proposal

Jan 12, 20064 mins
Cisco SystemsHDTVsMobile

An industry group seeking common ground on the emerging IEEE 802.11n high-speed wireless LAN specification has agreed on a compromise proposal that may form the basis of a final standard.

The joint proposal group, which includes backers of all the major factions in the fight over how to boost the speed and range of WLANs, late Wednesday approved a proposal by a unanimous online vote with two abstentions, according to Bill McFarland, CTO at Atheros Communications, a semiconductor vendor that belongs to the group. Over the next two working days, the group will finalize the plan in a face-to-face forum in Kona, Hawaii. Barring any unforeseen problems, it will present the proposal to the IEEE 802.11n Working Group at its regularly scheduled meeting next week in the same location.

The 802.11n standard is intended to be the next step up in WLANs, offering real throughput of more than 100Mbps and support for multiple VoIP and video streams. But the road to a standard has been long and rocky. The joint proposal group was formed in the middle of last year after none of the plans that had yet been proposed could garner enough votes for approval. The Enhanced Wireless Consortium (EWC) was created in October, with the backing of heavyweights including Intel, Cisco and Atheros, and proposed its own plan.

On Thursday, the joint proposal group adopted the EWC’s approach along with some elements from its own work, McFarland said. With this backing, the plan is likely to be approved by the official IEEE task group when it votes next week, McFarland said.

In addition to speed of more than 100Mbps, which users probably will get all around a typical home, the technology includes features for improved quality of service, he said. Consumers should be able to transmit multiple streams of high-definition TV. With speeds in excess of Fast Ethernet, the technology now used most often for desktop LAN connections, small and midsize businesses will be able to go entirely wireless without paying a bandwidth penalty, McFarland said. In addition, new features in the standard proposal will allow for simultaneous calls on 50 or more VoIP phones, he added.

Under the proposal passed Wednesday, 802.11n gear would use multiple antennas in both clients and access points to increase bandwidth and improve range by about 50%, McFarland said. Along with the antenna technology, it uses a coding method called space-time block codes that will make networks more reliable and lead to improved performance even if only the access point has multiple antennas, he said.

The proposal also includes features that speed up the way a LAN ensures packets have gotten to their destinations correctly, called packet aggregation and block acknowledgement. Instead of the network having to acknowledge each packet that comes through, it groups packets together and checks many at once, eliminating back-and-forth network signaling that could slow down the network, McFarland said.

The one major technology from the joint proposal group that was included is an error correction mechanism called low-density parity check mode, which should make networks more reliable and give them a longer range, McFarland said.

Even if the new proposal gets the required 75% approval vote at the IEEE 802.11n task group next week, the standard probably would not get formally sign-off for about a year, McFarland said. But partly because the standards process has taken so long and vendors have gained experience with the new technology, there will probably be pre-standard products on the market in the middle of this year that are mostly interoperable and can be upgraded to the final standard via software or firmware upgrade, he said.

The Wi-Fi Alliance, which certifies interoperability of 802.11 products, does not give products Wi-Fi certification until after each IEEE standard is formally adopted.