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10Gbps Wireless Transfers
Erasei writes "NTT Science and Core Technology Laboratory Group has developed a wireless communications that is capable of transmitting data at speeds of up to 10Gbps. In order to achieve such high data transmission speeds, the system uses the as-yet-unused 120GHz frequency band. The actual bandwidth the system uses is 17GHz, and the method of modulation employed is amplitude shift keying."
Looks like about 2 feet. And it would seem to be highly directional.
Not sure what this would be usefull for..
The law is a weapon of the government, not a protection for the likes of you. Surely you understand that.
That's 19 megabit over cell phone. This is not over cell phone.
Regards, Adam.
NTT Develops 10Gbps Wireless System
October 18, 2002 (TOKYO) -- NTT Science and Core Technology Laboratory Group has developed a wireless communications system using the 120GHz band.
The system, which is capable of transmitting data at speeds of up to 10Gbps, was displayed at the "NTT R&D Forum 2002" event held Oct. 11 in Atsugi.
The new system is four times as fast as the 2.5Gbps wireless system NTT put on show at the same event in 2001. This is the first time the laboratory experimented with a 10Gbps wireless system (photo). There are many potential uses for such a high-speed wireless technology, such as for 10Gbps wireless Ethernet links or for radio links between different buildings where a high volume of data has to be sent to and fro. NTT plans to announce the new system at the "Asia-Pacific Microwave Conference" (APMC) to be held in Kyoto in November.
In order to achieve such high data transmission speeds, the system uses the as-yet-unused 120GHz frequency band. The actual bandwidth the system uses is 17GHz, and the method of modulation employed is amplitude shift keying (ASK), the simplest method of amplitude modulation for digital signals. According to an NTT source, by modifying the modulation method, the throughput rate will be improved.
NTT also used optical communications technology to make the 120GHz system possible. A 120GHz optical pulse signal is generated, and then undergoes amplitude modulation. After modulation, the signal is picked up by a special photodiode capable of responding with the high-speed signal. The output from the photodiode is then transmitted as a wireless signal. The special photodiode used was developed with NTT's own technology, and can handle optical inputs of up to 300GHz.
The main difference between last year's system and the new one is that the receiver frequency detection circuitry has been redesigned, meaning that the receiver can detect signals over a wider bandwidth, and thus the system can operate at faster speeds. The new detection circuit can receive signals from an 8.5GHz band at maximum. Because the system employs two detection circuits working in tandem, the finished system realizes more than a 17GHz band.
At "NTT R&D Forum 2002," the system was shown transmitting non-compressed HDTV-quality (1.5Gbps) video data. In order to extend the range of the transmission, a 20cm-diameter lens was used to focus the beam. In the laboratory, a 10m range for the system has been confirmed, but NTT is expecting to try and extend the range to 100m.
Radio waves at 120GHZ travel like light. The signal wont go through walls at all.
It is OPTICAL not RF. For Pete's sake, just use a friggin laser over open air. It's cheap, higher bandwidth and lets you do cool tricks using a couple of well used chalk board erasers. One use that leaps right to the front of MY mind is one of those nifty wireless video gadgets for your living room. "For only $750,000.00 you can beam S-Video quality signals from your DVD player to your big screen (up to 20 feet) WITHOUT WIRES!!!"
It wont penetrate anything solid. It will do slightly better in fog than lasers, but not a hell of a lot ... in short, not terribly usefull.
"NTT also used optical communications technology to make the 120GHz system possible. ...After modulation, the signal is picked up by a special photodiode capable of responding with the high-speed signal. ...In order to extend the range of the transmission, a 20cm-diameter lens was used to focus the beam."
Also known as Fast Ronja. Cool as hell though.
Caveat Emptor is not a business model.
not to mention (i'm guessing) a hella lot more range,
You guessed wrong. The range goes down as the frequency goes up. The higher the frequency, the more the radiation behaves like light, which is really just terahertz radio. As you get higher and higher frequencies, walls and such become more and more opaque to the signals. Until eventually they won't travel thru the walls at all, just like light.
If you want long range, you need lower frequencies. If you want to send a signal across the ocean, you need KHz radio waves (short wave radio). If you want to send a signal around the state you need AM radio at ~1MHz. If you want to send your signal around a city you can use FM at ~100MHz. By the time you get up to 2.4GHz you can only send your signal across a few rooms. Yes, I know I'm simplifying the differences in transmission power. But a short wave ham can reach across the world with less power than an AM station uses to cover a state, and the AM station uses less power still than the FM station which only covers a city or so.
Now, point to point is a whole different story. If you have direct line of sight you can send extremely high frequencies across significant distances. But the curvature of the Earth prevents you from sending stuff too far. Not to mention buildings and other obstructions.
Remember earlier in the week when /.ers were hammering the story about the guys in Africa who were using HF to send email using packet radio? Every frequency range has its up and down sides. Heck, I think the Navy uses (used?) ULF (Ultra Low Frequency) to communicate with submarines. Only problem is that at those frequencies, a one bandwidth length antenna is a few miles long....
these are two completely different issues - security is normally implemented on top of a high speed link (e.g. encryption) or on a level below (protecting cables physically from access etc.). the beauty of a layered system is that the different layers can be developed separately without interfering with other layers.
There shouldn't be a problem making high speed transmitters or receivers fast enough for speeds higher than the current rate of transmission between IRDA devices.
The problem is twofold.
On one side, there is large demand for some things to remain backards compatible with legacy devices like VCRs and Stereos, which is much easier to do when your standard rate of transmission is lower.
However, with that said, I believe the real "problem" with IRDA lies in on the error detection and correction side of things. The same is true of TCP/IP. It could be significantly faster (ala UDP) if we did not want guarenteed delivery.
IRDA is significantly slower than things like microwave PTP because they leave room in the modulation timing for not quite perfectly aligned transmissions. Whilst motor skills in the human hand allow for the precision neccessary to enact a successful transmission, more often than not there will be either vertical or latteral movement in the outer extremities of the device (usually the end with the transmitting diode on it) which would cause transmissions with faster modulation to fail... as it is, the millisecond sync loss is (usually) able to be recovered from my simply resending the data sent since the last acknowledgement packet.
In short, yes, you could do it, but you would have to hold those things *REALLY* steady, maybe to the point of having to set them on a solid surface whenever you wanted them to communicate... since the manufacturers are catering to the general unwashed masses, they create the device to be idiot proof ala very slow transmission speeds and large error windows.
Hope this helps.
Video meliora proboque deteriora sequor - Ovidius
Yes, we do. Do you? It uses optical means to generate the 120 GHz RF inside each unit, NOT BETWEEN THE BOXES.
Obligatory nit: Optical is RF. Just really high in frequency (THz).
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
I couldn't find anything on what exactly is the centre frequency for this, but around 120GHz is certainly allocated and in use--119.98-120.02 to ham use and 101-120 GHz to radio astronomy (search for intentional extraterrestrial emission). Perhaps they mean "previously unused for wireless computer communication"?
It may be faster than current wired tech for home and office use, but it is definetely slower than current fiber optic systems. These can carry between 200 and 300 channels each one at 10 Gbit/s or about 100 channels at 40 Gbit/s
Mind that the system proposed by NTT is intented for point to point communication and not for LANs.
Many birds can "feel" radar pulses, and their typical response is to fold their wings and fall. One effect of this is the fact that, if there are birds in the vicinity of an airport, pilots are encouraged to turn on their aircraft's radar to avoid birdstrikes on takeoff.