A year ago, 802.11n - the IEEE's proposed faster Wi-Fi standard - was a gleam in the industry’s eye. Now, 60-odd partial or complete proposals for how to achieve above-100 Mbit/s WLAN speeds have been submitted to the IEEE 802.11 Working Group, which is reviewing them.
Faster Wi-Fi LANs will allow the industry more wiggle room for applications such as VoIP, which can clobber performance in highly utilised Wi-Fi networks when many VoIP callers associate to a single access point, particularly in 11 Mbit/s 802.11b environments.
At this juncture, the Wi-Fi industry has one of those situations in which two large competing consortia, each with its own complete 802.11n proposal, could threaten to stall standards (see The two-horse race for faster Wi-Fi). Both camps have included multiple input, multiple output (MIMO) technology - the fair-haired wireless child of the decade for spectral efficiency - in their proposals. It is also likely that the ultimate standard will include provisions for power management.
“Battery life [in client devices] needs to extend from hours to days,” says Sheung Li, a product line manager at Atheros Communications and the TGn Sync coalition’s representative to the IEEE 802.11 Working Group. TGn Sync is one of the two large vendor groups that has submitted an 802.11n proposal. Its proposal includes a power management provision, including a way to enable products to operate in very low power modes.
TGn Sync’s proposal calls for 243 Mbit/s Wi-Fi speeds with two antennas and up to 600 Mbit/s with four. Its members include Agere, Atheros, Cisco, Intel, Marvell, Nokia, Nortel, Philips, Samsung, Sanyo, Sony and Toshiba.
The proposal of the other major group, WWiSE (for “Worldwide Spectral Efficiency”), comprising Airgo Networks, the late, lamented Bermai, Broadcom, Conexant, STMicroelectronic and TI, aims for 135 Mbit/s mandatory speeds using two antennas and up to 540 Mbit/s in optional mode using four antennas.
Rolf De Vegt, business representative for Airgo in the WWiSE group of companies, notes that WWiSE is not charging any royalties to vendors who build according to the WWiSE spec. “We believe that this is a different model and will lower costs,” he says.
Analysts expect the 802.11n standard to appear in roughly 18 months.