The two major factions in the race to develop the standard for the next generation of Wi-Fi, 802.11n, have agreed to submit a unified proposal to the IEEE.

The groups, TGn Sync and WWiSE, together with a third group, MITMOT, said late last month they will merge their respective proposals as a draft which will be sent to the IEEE in September. A final version will be submitted in November.

TGn Sync and WWiSE have been touting their respective suggestions for how 802.11n should work for almost a year now. With powerful wireless industry backers behind each proposal, these two groups quickly emerged as the most likely contenders for the final 802.11n specification, which is expected to take Wi-Fi speeds to 540Mbps.

WWiSE has won the support of Texas Instruments, Broadcom, Conexant, STMicro, Airgo and Bermai, and later Motorola, which had originally submitted a proposal of its own. Nokia also threw its hat into the WWiSE ring after initially supporting TGn Sync. TGn Sync's supporters include Intel, Atheros, Agere, Infineon, Cisco, Qualcomm, Nortel, Mitsubishi, Sony, Panasonic, Philips, Samsung, Sanyo, Toshiba.

In March, TGn Sync took a lead in the IEEE Task Group voting, but with an insufficient majority to knock WWiSE out of the running. A follow-up vote in May failed to establish TGn Sync as a clear winner - as it's supporters had hoped. Rather than see the 802.11n standards-setting process become deadlocked, as has happened in other cases, most notably ultrawideband, TGn Sync and WWiSE have clearly realised it makes more sense to work together than against each other.

In reality, there was relatively little to differentiate the two proposals, and if they can indeed submit a joint proposal next month, it seems certain that the merged specification will be approved by the IEEE 802.11n Task Group - aka TGn - as the foundation for the future standard. TGn is expected to take possession of the specification in January, if all goes according to plan.

Both proposals are based on the Multiple Input, Multiple Output (MIMO) many-antennae technique and Orthogonal Frequency Division Multiplexing (OFDM) to boost data throughput rates using two- and four-antenna arrays. They also tout the use of 20MHz and 40MHz channel widths, for backward compatibility with today's Wi-Fi kit and room for high-bandwidth networks, respectively. It also includes a 10MHz channel width. Both proposals use spatial multiplexing techniques to spread the data across the various antennae, essentially turning a serial data steam into multiple parallel streams to boost throughput.

They differ in the refinements then applied to the signals. TGn Sync uses an Extended Modulation Coding Scheme (MCS) and Basic Beamforming to "increase the speed and reliability of data links under conditions that disrupt many MIMO networks", it claims. It also believes it has 802.11b compatibility sorted, something that doesn't appear to be the case with WWiSE, which is focusing on 802.11a and g support.

Source