After much wrangling between opposing interests among the members of the IEEE, a first draft for the WiFi IEEE 802.11n specification will be voted on by the membership later this week.

The protocol allows designers to create a beacon that tells other devices to be quiet and tells all devices using the same access point when their timeslot is and when they can transmit. This prevents data collision. It also allows devices to stay asleep, saving power until it is their time to send or receive.

One of the first benefits will be for providers looking to offer what is called in the industry "triple play service provision": voice, video and data.

Products to emerge mid-year

The compromise draft is expected to pass, according to Bill McFarland, a member of the IEEE and CTO at Atheros.

Moving from first draft to final approval will take about a year. However, 802.11n products are expected to ship by midyear, McFarland said.

"Long before final ratification, the draft becomes stable, and once the core is extremely consistent, it makes people feel comfortable to design products," McFarland said.

The benefits of 802.11n are quite dramatic. Performance at the physical layer is expected to reach 300Mbps in initial products using two antennas, then over time scaling to 600Mbps using four antennas.

Wireless 10/10Bast T Ethernet

Actual throughput at the application level is expected to be 100Mbps, equivalent to 100/10Base T wired Ethernet networks.

The range of 802.11n is also expected to improve by as much as 50 per cent, according to McFarland, by using Beam Forming technology which focuses energy in a particular direction on both send and receive.

Another technology called STBC [Space Time Block Coding] will reduce signal drop out by using multiple antennas for redundancy. This technology in particular is key to enhancing the VOIP user experience.

Finally, packet aggregation and block acknowledgement protocols will reduce power consumption and data collisions in a congested environment by building a so-called super-frame to send multiple packets simultaneously.

Although it may not immediately replace wired Ethernet for the enterprise, for smaller companies using 100/10 BaseT, IEEE 802.11n may prove to be a less expensive alternative.