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Gigabit Wi-Fi

Although the IEEE 802.11n specification is still a year or more away from release, a small group of engineers is already moving ahead to the next generation of wireless networking. The goal? Gigabit Wi-Fi, to match the wired gigabit Ethernet links of today’s PCs, writes Mark Hachman in ExtremeTech.

A working group is preparing to propose what may eventually be known as IEEE 802.11 VHT (Very High Throughput), a likely successor to 802.11n. Throughput in excess of one gigabit per second, roughly ten times that of the 802.11n specification, is expected.

The IEEE has yet to formally approve what’s known as a PAR, or a Project Approval Request, the first step on the road to an IEEE standard, although that approval is expected, says ExtremeTech’s Hachman.

It would use two unlicensed frequency bands; 5GHz (for longer range) and 60 Ghz (for shorter ranges), It would exclude 2.4GHz operation and ensuring backward compatibility and coexistence with legacy IEEE802.11a/n devices in the 5GHz unlicensed band. Currently the IEEE 802.15.3c effort (at 60 GHz), is aimed at sending uncompressed high definition video between a set-top box and a wall-mounted LCD TV.

According to James Gilb, the technical editor for the WirelessHD consortium and the maintainer of the 802.11 VHT PAR page, products could hit the market around 2011 or 2012.

Two IEEE 802.11 VHT PARs have been submitted, one for 60 GHz and one for 5 GHz. More updates are expected in the second quarter of 2009, according to Bruce Kraemer, the chairman of the IEEE Working Group.

“There are no technical agreements on the project plan since it has been concentrating on a basic objective statement for the PAR,” Kraemer added.

The 5GHz PAR proposes a single-link throughput of 500 Mbits/s.

The 60-GHz proposal would be capable of a gigabit per second, using the wider swath of spectrum available, from 57 to 66 GHz. An OFDMA scheme may assign a user “chunks” of bandwidth measured in time and frequency. The chunks would then be divided by the number of users, in Motorola’s plan.

The 60-GHz version is hoping to avoid conflict with an existing specification that offers similar capabilities: IEEE 802.15.3, which is designed for “personal area networks” running at speeds up to 55 Mbits/s or so, and the faster IEEE 802.15.3c which is manifested in the WirelessHD group, currently utilizing SiBEAM’s chips running on the 60-GHz band.

Co-existence with other 60-GHz systems is a requirement in the PAR.

According to the 60-GHz working group, the proposal will maintain the “802.11 user experience” – with base stations, access points, and clients. The group anticipates that future Wi-Fi radio will access the familiar 2.4-GHz/5-GHz Wi-Fi networks, but also 60-GHz networks as well.

Now it appears that 802.15.3 and the new 802.11 VHT technology “will go out as separate standards, and we’ll let the market decide,” Glib told ExtremeTech.

There are other standards devoted to delivering HDTV content around the home:

Ultra Wide Band. The WiMedia standard uses a swath of frequencies between 3-5 GHz (or higher) as an alternative to HDMI cable for connecting HD players (or computers) to monitors. Tzero Technologies says the technology can cover 20m to 30m in range compared to typically 2m HDMI cables. Price is the bad news, with a transmitter/receiver pair selling for around $700.
The 5 GHz band. Amimon, meanwhile, has been touting its 5-GHz-based technology for wireless HDTV video distribution. And Amimon claims uncompressed HD video transmission as one of its key advantages and claims to deliver 3-Gbps data rates in 20-Mhz on the unlicensed 5 GHz band using the Wireless High Definition Interface standard.

Related Dailywireless articles on Gigabit WiFi include; WHDI: Angling for Wireless HD, Standards Battle at 60 GHz and FiOS: Too Risky?