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June 15, 2007

60 Ghz wireless at one tenth the cost

60 Ghz millimeter communication at one tenth the cost with new Toshiba Corp. 60-GHz receiver CMOS chip instead of GaAs

60Ghz provides a total data rate of 312 Mbps (down/up links are 155.52 Mbps).

Current prices seem to be in the $10,000-15000 range. So if the full system price can be brought down to 10% then it would be $1000-1500. But other components may not see the price reduction.

Here is a pdf that describes applications using 60Ghz wireless communication

For many applications, 60 GHz radios have become the technology of choice, based on being license-free, highly immune to interference, and easy to install. The achievable distance is the main limitation of 60 GHz radios. Based on the geographic area of deployment and link availability requirements, 60 GHz radios can be confidently deployed at maximum distances ranging from 400 to 1000 meters.

License-Free Spectrum. The FCC allocated an un-precedented 7 GHz of unchannelized
spectrum for license-free operation between 57-64 GHz – this compares to
only about 500 MHz of spectrum allocated between 2-6 GHz for WiFi and other licensefree applications. For the first time, sufficient spectrum was allocated to make possible multi-gigabit RF links.

Narrow Beams Antennas. A 10-inch dish antenna can achieve 40 dBi of gain with a
half-power beamwidth of 1.4 degrees. A corresponding 5.8 GHz antenna would have
beamwidth ten times larger. This narrow beamwidth allows multiple 60 GHz radios to be
installed on the same roof-top or mast, even if they are all operating at the transmit and receive frequencies.

Oxygen Absorption. This is a unique property that does not affect lower-frequency
radios. Oxygen attenuates 60 GHz signals by 12-16 dB per kilometer (i.e., half of the
energy is absorbed for every 200 meters the signal travels), which is the main reason that 60 GHz links cannot cover the distances achieved by other millimeter-wave links. The impact of the small beam sizes coupled with oxygen absorption makes the links highly immune to interference from other 60 GHz radios, since another link in the immediate vicinity will not interfere if its path is even moderately different from the first link, and any radio operating beyond the immediate vicinity (even on the exact same trajectory) will have its signal severely attenuated by the oxygen attenuation. These same two factors make the signal highly secure – in order to intercept the signal, one would have to locate a receiver lined up on the exact same trajectory, and in the immediate locale of the targeted transmitter.

Rainfall Limitations. Like all radio links that operate above 10 GHz, intense rainfall significantly limits the distance over which 60 GHz links can transmit data error-free.

60 GHz links are limited by their performance during periods of heavy rain. FSO links
are limited by their performance during periods of heavy fog. Because heavy rain and
heavy fog to not occur at the same time, a hybrid link that has both a 60 GHz link and a FSO link can operate at the maximum distance of the shorter of the two links in clear weather. It is possible to create a very high availability, full-time gigabit speed link at up to one kilometer using this type of hybrid link. Customers also benefit from the hardware redundancy, providing partial protection if one of the two links experiences a hardware failure. The only downside to this type of link is cost, as gigabit FSO links are more expensive than gigabit 60 GHz links.

For the more cost-sensitive customer, another hybrid alternative is to pair a gigabit 60 GHz link with a lower-capacity 5 GHz link. Since the 5 GHz link is immune to rainfall, it can be used as a lower-speed fallback for periods when the 60 GHz link is impaired by heavy rainfall. If a customer is able to tolerate the lower speed link performance 1% of the time, then the 60 GHz link distance can be set at the 99% availability distance, which from the distance chart (above) can be up to 900 meters. For a small premium over the cost of the gigabit link, using a $3,000 24 Mbps performance 5 GHz link as a fall-back can provide a customer full gigabit performance 99% of the time and 24 Mbps 1% of the time.


300 Ghz Millimeter wave chips are also used to security scanning through clothing

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