German Researchers Hit 40 Gbps On Wireless Link

judgecorp writes "German researchers from the Fraunhover and Karlsruhe institutes have achieved 40Gbps transfers over 1km using a wireless link. The new record raises the hope that point-to-point wireless could be used instead of expensive fibers in some rural broadband applications." Partially thanks to transmitting between 200GHz and 280GHz.

Not good for long haul use

[Muad'Dave]

This band is not useful for long haul carriage due to atmospheric water vapor absorption. According to this chart [eoportal.org], absorption between 200 and 280 GHz varies between 3 and 40 dB/km. That means at the low end only 50% of your signal is absorbed every km. At the high end, only 1/10,000th of your signal remains after each km.

this post [slashdot.org] speaks to similar issues including refraction.