Wild excitement over terahertz wireless demo
It’s not the messiah, just a very fast modulation
Japanese researchers have demonstrated a 3Gbps transmission on a 542GHz carrier. It’s interesting, even exciting, in its own right: at the very least, it’s certain to be surpassed before such technologies become part of the commercial product landscape.
Operating radiocomms in the 300GHz – 3THz band poses a host of challenges, all the way from the silicon (difficult to build at a low enough cost for consumer-level devices) up to the air interface (dealing with signal propagation at such extremely high frequencies).
The Tokyo Institute of Technology researchers used a resonant tunnelling diode as the basis for its 3Gbps demonstration. The system they developed used the current feeding the device as the control that tuned the device’s signals and get it to operate in the Terahertz band.
They believe that transmissions up to 100Gbps will be possible – but, as with any transmission at such high frequencies, range will be extremely limited (currently around 10 meters).
However, El Reg can’t resist some amount of irritation that the development is treated as if it cannot stand on its own without being hitched to a “new WiFi” tag. The air interface – in other words, the physical layer – is one thing; WiFi (actually an accreditation tag) or more accurately 802.11 is a whole suite of protocols, only one part of which is the physical layer.
An abstract of the modulation technique can be found here. ®
I have to echo 'El Reg' on the irritation about the use of the word Wi-Fi.
Frequencies this high normally require line of sight, are normally very directional and useless at penetrating through internal stud walls, let alone brick. The cost to get any decent sort of power output is high, the losses (in connections, coax) are massive. So in other words, nothing like Wi-Fi.
I do hate seeing buzz words dropped in just because the author has tried to 'stay in touch' with the tech, without fully understanding it.
A very naughty modulation.
But oh so right.
In free space..
With a couple of roof top dishes it might be more useful for connecting a couple of buildings on a campus till you get fibre in.
100GHz to 400GHz wireless has been around quite a while. I wonder what exactly is new about this.