60 GHz Wireless Backhaul
"60 GHz: A Frequency to Watch"
(source: LightReading 7-10-14)
It's now likely that 60GHz will become the next big frequency in wireless world, with both short-range and wider area applications ahead for the tiny beams of this unlicensed millimeter radio technology.
The frequency -- part of the V-Band frequencies in the US -- is considered among the millimeter radio (mmWave) bands. Millimeter wave radios ride on frequencies from 30GHz to 300GHz. Until recently, 60GHz has typically been used for military communications. (See 60GHz Giddyup.)
Recent acquisitions by massive technology players indicate growing interest in the technology and the associated patents. Qualcomm Inc. (Nasdaq: QCOM) bought Wilocity recently to combine 60GHz WiGig technology with WiFi.Google (Nasdaq: GOOG) bought Alpental, a startup that, according to one of its founders, is using 60GHz to develop a "hyper scalable mmWave networking solution for dense urban nextGen 5G & WiFi." (See Qualcomm Advances WiGig With Wilocity Buy and Google Buys Alpental for Potential 5G Future.)
Why 60GHz, and why now? Here are a few pointers for you.
WiGig: A new short-range wireless specification -- using the Institute of Electrical and Electronics Engineers Inc. (IEEE) 802.11ad specification -- that can link devices at up to 7 Gbit/s over a distance of up to 12 meters. That's 10 times faster than the current 802.11n WiFi, though with less range. This makes the technology ideal for wirelessly delivering high-definition video in the home. The Wi-Fi Alliance is expecting WiGig-certified products to arrive in 2015. (SeeWi-Fi Alliance, WiGig Align to Make WiFi Super Fast.)
Wireless backhaul: Particularly for small cells, operators can use the 60GHz radios to connect small cells to a fiber hub. (See More Startups Target Small-Cell Backhaul.)
Wireless bridges: These are useful for providing extra capacity at events, ad-hoc networks, and private high-speed enterprise links. (See Pushing 60.)
Wireless video: Some startups have jumped the gun on the WiGig standard and plowed ahead with their own 60GHz video connectivity using the Sony-backed WirelessHD standard.
A global unlicensed band exists at 57-64GHz. It is largely uncongested compared to the 2.5GHz and 5GHz public bands currently used for WiFi. (SeeFCC to Enable Fast Streaming With New 60GHz Rules.)
There's also a lot of it. "The 60 GHz band boasts a wide spectrum of up to 9GHz that is typically divided into channels of roughly 2GHz each," Intel Corp.(Nasdaq: INTC)'s LL Yang wrote in an article on the prospects for the wide-area and short-range use of the technology. Spectrum availability is "unmatched" by any of the lower-frequency bands.
The spectrum is now open and approved for use across much of the world. This includes the US, Europe, and much of Asia, including China. Here's a spectrum map from Agilent on the band's global availability.[(Source: Agilent)]
As we've already seen, 60GHz technology is expected to offer blazing wireless transmission speeds.
Issues with 60GHz
No technology is ever perfect, right?
Transmissions at 60GHz have less range for a given transmit power than 5GHz WiFi, because of path loss as the electromagnetic wave moves through the air, and 60GHz transmissions can struggle to penetrate walls. There is also a substantial RF oxygen absorption peak in the 60GHz band, which gets more pronounced at ranges beyond 100 meters, as Agilent notes in a paper on the technology. Using a high-gain adaptive antenna array can help make up for some of these issues with using 60GHz for wider area applications.