Given that the oxygen absorption loss at 60 GHz isn't a significant number ! it is only in the range of 4 dB for a distance of 200 m. Thus, it is not a solid reason for favouring 60 GHz band for indoor scenarios more than outdoor scenarios
Dear Mohamed:
Millimetre-wave transmission in the 60 GHz range is seen to be a promising method in order to meet the demanding requirements of future Wireless systems with regard to increasing data rates. The use of millimetre-wave techniques at 60 GHz offers many advantages for short-range systems like IOT, 5G etc.. compared to radio methods at lower frequencies.
The main advantages of this frequency band are, on the one hand, the large (license-free) bandwidth which permits high data rates and in the short wavelength where the case suitable to the indoor you asking for, then it leads to small antenna dimensions even with multi-antenna systems!!!
Furthermore, there is no interference with existing radio systems becuase in the lower frequencies the spectrum is condense by the frequencies.
In view of the high radio field attenuation and the high transmission losses of walls, the radio cells are small, but interferences by other millimetre-wave systems and neighbouring radio cells are small as well.
concerning the loss you ask for from the oxygen absorption loss at 60 GHz
thanks to the Antenna researchers working on the directectivity that will decrease this loss.
Thanks,
Yehya NASSER.
I guess it is more due to spreading loss and the high penetration loss in materials such as walls.
I think Yehya makes the important points. Reasons for favoring 60 GHz, or anything at these extremely high frequencies, are that the advantages might outweigh the disadvantages. Yes, propagation loss is great and absorption by obstacles significant, but in some cases, these liabilities won't be enough to offset the advantages. Channel capacity can be great, when you are not so constrained in the width of the RF channel. Antenna gain in specific directions can be tuned more accurately. And abundance of spectrum is another point. Plus, in indoor environments, you might prefer for the signal to not propagate very far. All depends on your needs.
But note that 5G cellular is also looking into these higher frequency bands. In part, the very small cells would benefit from the signal from each base station not propagating very far. Everything in design is a matter of compromise.
Thanks all for the replies, I agree with all the replies. However my point is why 60 GHz specifically !!? I mean for a center Frequency like 28 or 73 GHz they satisfy all the aforementioned characteristics in the replies, but they are used in the current research for outdoor scenarios only (so what makes the 60 GHz specifically unique for indoor applications, given that the oxygen absorption is not a convincing reason as I mentioned before!)
I hope now my point is more clear
I think Nasser mentioned an important point: license-free. It seems that the 60 GHz band will be globally allocated for ISM applications. I may be wrong here, as I am not an expert on this, but it occurs to me that most major ISM applications are indoors?
Thanks alot Sergi ! yes exactly I agree with you, until now that is my only conclusion also so far ! since the Federal Communications Commission has allocated the frequency band from 57 to 64 GHz for unlicensed wireless systems, so I guess that is the most reasonable conclusion
First the band is available, second INDOOR PENETRATION is the killer rationale. The rest is true but less critical
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