The first draft of the Wi-Fi 802.11nspec will finally be voted on this week, after much wrangling between opposing interests of members in the IEEE.
The compromise draft, created by a joint sub-committee, is expected to pass, according to Bill McFarland, a member of the IEEE and CTO at Atheros.
The original debate divided the group into two camps. Some believed that ratification of the specification was taking too long, causing the EWC (Enhanced Wireless Consortium), made up of mainstream Wi-Fi players Atheros, Cisco, Intel, Symbol and Toshiba was formed. Others, including Motorola, Nokia, and Samsung, wanted more in the way of power management for handsets and VoIP devices.
From first draft to final approval will take about a year. However, 802.11n products are expected to ship by mid-year, 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 dramatic. Performance at the physical layer is expected to reach 300Mbit/s in initial products using two antennas, then over time scaling to 600Mbit/s using four antennas.
Actual throughput at the application level is expected to be 100Mbit/s, equivalent to 100/10BaseT wired Ethernet networks.
The range of 802.11n is also expected to improve by as much as 50 percent, 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. The technology is key to improving the quality of voice-over-IP.
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.
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, preventing collision. It also allows devices to stay asleep, saving power until it is their time to send or receive.