The Wireless Gigabit Alliance recently announced that it has published the certification-ready 1.1 specification of its wireless system, and it includes some new capabilities, like a framework for video connectors. But given that even 5GHz WiFi is notorious for spotty reception mere feet from the offending wireless router, how will WiGig, which uses an incredible 60GHz frequency, ever manage to transmit information to devices that aren’t literally pressed up against the router?
First, a quick rundown of what WiGig is. WiGig is a specification for hardware that uses 60GHz frequencies to transmit up to 7 gigabits of data per second over the air; for comparison, 802.11n WiFi tops out at a few hundred megabits per second. In other words, a download of an HD episode of Archer on WiGig would take mere seconds, even without perfect reception. The system has been in development for some years now. The WiGig Alliance recently pegged the launch of capable devices for the first half of 2012.
WiGig is sufficiently advanced to have its own IEEE 802.11 standard, coded as 802.11ad. Using it at the time of release will require some new hardware both to send and receive signal, similar to when 5GHz started to make its way onto the market. Unlike 5GHz WiFi, though, WiGig’s design includes methods for avoiding the decay problems that higher-frequency transmissions usually have.
Beamforming uses directional antennas to focus a signal into a concentrated “beam.”
Wireless Gigabit Alliance
To overcome signal decay, WiGig uses a process called adaptive beamforming (it’s not the first or only system to do so, but is heavily reliant on it). With a combination of physical antennas on the devices and algorithms to tune the signal, WiGig devices effectively shoot their signals back and forth at each other in a narrow, targeted beam.
Antennas in the devices—say, a router—each have a broad reception area for a router to see devices in. When a device that wants to use the 60GHz connection is brought into that area, it begins communicating with the antennas to fine tune the antenna’s signal to maximize connection speed.
The antennas do this by adjusting both the amplitudes and the phase shifts of their broadcasted waves. The reception of the signal is optimized by minimizing different kinds of problems: the error between the antenna’s output and the expected signal, for example, or the signal-to-interference ratio.
When the phase shifts and amplitudes of multiple sources of waves are tweaked to work together and combine their pings in the right way, they create “lobes” of excellent reception areas. An unfortunate result of the lobes is that there are also null areas outside the lobes where there is no coverage at all, which doesn’t bode well for WiGig’s ability to blanket a particular area with simultaneous reception—at least, not without an army of routers and antennas.
As long as a device is within range of a particular antenna on the router, the antenna and receiver can run the digital optimization process fairly quickly to establish a concentrated signal beam. But “quickly” is as specific as the released sources by the WiGig alliance gets, so the speed of connection could be anywhere from a fraction of a second to multiple seconds, or longer.
The time it takes to establish the fastest beam could also depend on the quality of equipment you pick up. But even factoring that in, we’re not sure we’ll be able to stroll around holding our WiGig-capable devices and maintain the 60GHz signal. Still, the specifications say the equipment must be able to fall back on 2.4GHz and 5GHz signals in the event that it loses the higher-speed connection.
Mobility isn’t the only downfall of WiGig, though—according to the WiGig Alliance, the beamforming of compliant equipment needs to be within line-of-sight of receiving devices in order to work well. Even a person stepping between two communicating devices can break the signal, though according to a whitepaper by the group, WiGig-compliant equipment can bounce beams off walls and ceilings in order to reach between devices.
According to the specifications, devices can work over distances “beyond 10 meters,” but it seems walls and ceilings will be an even bigger obstacle for 60GHz WiFi than they already are for 2.4GHz and 5GHz signals. Bouncing the signal may work around some setups, but not all; no one will know whether a single router will cover more than one room until there is some actual hardware to try.
One of the more interesting capabilities of WiGig is an included compliance with audio-visual equipment, including with HDMI and DisplayPort interfaces. In theory, this compliance means that you could plug some kind of dongle into your TV’s HDMI port that can participate in all of the signal optimization processes, connect your computer to it over the superfast WiFi, and stream all the HD video you can gets your hands on (provided both your computer, router, and dongle are 802.11ad-capable and within range of each other, of course).
In the same vein, the new specifications include compatibility with USB and PCIe interfaces. This way potential users who want to get on board with WiGig immediately will be able to hook their computers up with dongles as well, instead of having to buy and install new wireless cards.
As of the second half of this year, manufacturers and adopters will be able to start testing and certifying their compatible devices with the 1.1 specification. WiGig dates have been pushed before, but we’d say 2012 is looking pretty good as the year we get our hands on some blazing, if still slightly fragile, WiFi.
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