Draft 2.0 of the 802.11n wireless-networking standard has been approved by an IEEE working group. The move means that 'draft 2.0' 100+Mbps (megabits per second) wireless LAN products could be on sale as early as summer 2007.
Around 83 percent of working group members approved the draft, more than the 75 percent votes. The vote suggests that after more than a year of often acrimonious debate, members of the group have finally got together behind the core technology.
Manufacturers of WLAN adaptors and access points can now introduce products that should require no substantive changes when the final standard is authorised. The final 802.11n standard is expected to be rubber stamped in late 2008.
The Wi-Fi Alliance last year said it was preparing an interoperability testing program for draft 2.0 equipment. Alliance officials said then that testing could begin by June 2007 at the latest. The Alliance will certify and brand WLAN products as draft 2.0 compliant, reversing a long-held policy to test only products that comply with a final IEEE standard.
The heart of the new standard is a technique called Mimo (multiple input multiple output). Mimo takes a stream of data, separates it into several streams using digital signal-processing magic, and transmits it over two or more antennae. The streams are received by two or more antennas and re-assembled into the original. But because of how this is done, and the way Mimo antennae exploit radio reflections called multipath, much more data can be packed into these transmissions.
The IEEE standard originally called for a minimum of 100+Mbps throughput. But so-called "draft 1" or "pre-11n" products already on the market are delivering 140-160Mbps. With more antennae, more power and other tweaks, many vendors say they expect to achieve more than 200Mbps, sometimes even faster.
At the regular IEEE 802.11 plenary this week, in Orlando, one attendee was network-security guru Matthew Gast. In his blog, Gast reported that of the 325 eligible voters, 306 voted. Of that number, 231 approved the draft, 46 voted against, and 28 abstained. Four votes were invalidated. Draft 2.0 received 3,163 comments roughly evenly divided between editorial and technical comments. Those indicate that there may be some additional changes to the draft over the coming months, but they are likely to be minor.