The IEEE 802.11n task group Wednesday night turned back a surprise move to adjourn this week's meeting, and then went on to hand a major setback to a vendor group backing one approach to super-high bandwidth wireless LANs.
Members of that group, TGnSync, had moved to adjourn this week's meeting in Cairns, without taking a second confirmation vote on the group's 11n technology proposal. But a majority of attendees voted to stay in session, and then began the confirmation vote.
Under IEEE rules, a proposal like this must win 75 percent of the vote to be accepted as the basis for a draft standard. At the first confirmation vote a few months ago, the TGnSync plan won backing from 57 percent.
But on Wednesday, the plan failed to get even a majority: only about 49 percent of those present voted for it.
That setback means the chief alternative plan, from a second vendor group called World-Wide Spectrum Efficiency (WWiSE), can now be reconsidered, along with the TGnSync plan.
Both plans are based on a technology called multiple-input/multiple-output (MIMO), which proponents say will boost WLAN throughput to over 300M bit/sec, though the standard will call for a minimum of about 100 M bit/sec. That compares to today's 802.11a and 11g throughput of 20-24M bit/sec.
MIMO breaks up a radio transmission into two or more data streams within one channel. Each stream is sent, and received, by a separate antenna, and then recombined on the other end. The result is that much more data can be sent over the available radio spectrum than is possible with standard transmissions today.
The differences, advocates of both groups say, is in a variety of implementation details. One example is that TGnSync proposes increasing the channel size from 20 MHz to 40 MHz; WWiSE favors keeping the existing 20 MHz size.
One WWiSE member says the defeat of the TGnSync plan should persuade both groups to come together quickly on a compromise scheme that will win the 75 percent backing that's needed.
"My interpretation [of this week's events] is that we have two groups with approximately equal support, and the way forward is for them to get together, get past some of the devisive issues, and come to the July IEEE meeting, or possibly the September meeting, with a joint proposal," says Jim Zyren, marketing director for the WLAN business unit of Conexant, a chipmaker in the WWiSE camp. "No one can get the 75 percent without a compromise."
Is a compromise technically feasible?
"Absolutely yes," Zyren says. "The technical differences are not that great. I've seen other standards-making efforts, with much greater differences come together. If all parties realize that compromise is essential, then compromise becomes quite possible."
Requests to TGnSync members Agere, Atheros, and Intel for comment on this week's votes have not yet been granted.