Whats next? How about 40Gbps using 240Ghz!

Researchers at the Fraunhofer Institute and Karlsruhe Institute of Technology in Germany have successfully transmitted 40 gigabits per second over a one-kilometer (0.62 miles) wireless link - a new world record. The technology, called Millilink, is the same speed as the fastest commercial fiber optic links, and could represent a major breakthrough for carrier backbones, broadband internet access in rural areas, and ultra-fast last mile access for customers who have not had fiber rolled out in their area.

To achieve 40Gbps, the researchers use an 80GHz block of wireless spectrum between 200 and 280GHz. By comparison, your WiFi router at home probably uses just 20MHz or 40 Mhz in the 2.4GHz or 5GHz range. As you can imagine, you can squeeze a lot more data into 80GHz of bandwidth than 20MHz. With such a vast amount of bandwidth, link speeds well beyond 40Gbps should be obtainable - but for now, it sounds like the researchers are using a fairly rudimentary transmission protocol. With some multiplexing, 100Gbps or more should be achievable.

Fraunhofer's Millilink chip, with III-V transistors capable of switching at 300GHz

There's also another interesting benefit of using such a high frequency: Higher frequencies have a shorter wavelength - and the shorter the wavelength, the smaller the antenna needs to be. In the case of Millilink, the transceiver chip measures just 4×1.5mm (pictured above). To generate such high frequencies, Fraunhofer uses its own III-V CMOS process to create transistors that are capable of operating at 300GHz. Link below to Karlsruhe Institute of Technology website.