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.
Group strikes agreement at last
The joint proposal group, which includes backers of all the major factions in the fight over how to boost the speed and range of wireless LANs, approved a proposal by a unanimous online vote with two abstentions, according to Bill McFarland, chief technology officer at Atheros, a semiconductor vendor that belongs to the group. Over the next two working days, the group will finalise 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 regular meeting.
The 802.11n standard is intended to be the next step up in wireless LANs, offering real throughput of more than 100Mbps (megabits per second) and support for multiple VoIP (voice over IP) 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 EWC (Enhanced Wireless Consortium) was created in October, with the backing of heavyweights including Intel, Cisco and Atheros, and proposed its own plan.
Yesterday, 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 Institute of Electrical and Electronics Engineers (IEEE) task group when it votes next week, McFarland said.
Even Airgo Networks, which last year criticised the creation of the EWC and said it would slow down the standards process, voted for the proposal that passed on Wednesday. The California company has been selling multiple-antenna technology for two years and counts among its customers Netgear, Buffalo and Linksys.
"Airgo believes this is an extremely positive development for the industry because it marks the return to an open forum process where broad-based industry discussions will lead to a ratified IEEE 802.11n standard," Airgo said in a statement. Airgo president and CEO Greg Raleigh said on Thursday that over the past few months, the EWC had gradually modified its own proposal to line up with that of the joint proposal group.
In addition to speed of more than 100Mbps, which users will probably get all around a typical home, the technology includes features for improved quality of service. 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 medium-sized 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 on Wednesday, 802.11n gear would use multiple antennas in both clients and access points to increase bandwidth and improve range by about 50 percent. Along with the antenna technology, it uses a coding method called space-time block codes, which will make networks more reliable and lead to improved performance.
The proposal also includes features that speed up the way a LAN ensures packets have reached their destinations correctly; these are 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 signalling that could slow down the network.
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.
Even if the new proposal gets the required 75 percent approval vote at the IEEE 802.11n task group next week, the standard would probably not get formal sign-off for about a year, McFarland said. However, 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 added – partly because the standards process has taken so long and vendors have gained experience with the new technology.
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.
The new technology will make wireless LANs far more useful to enterprises, which eventually are likely to go entirely wireless within buildings, said Craig Mathias, principal at advisory and systems integration company Farpoint Group, which is based in Massachusetts. Wednesday's breakthrough will help bring a new standard by the end of the year, even though there are probably more debates ahead about details, he said.
"If that had not happened, we would probably not have had an 11n standard this year," Mathias said.
"We have more than enough spectrum now, but we can make better use of it with 11n, so we'll have more than enough capacity to meet the future needs of any enterprise."