Moreno Posted July 27, 2019 Author Share Posted July 27, 2019 (edited) On 7/25/2019 at 11:26 AM, Endy0816 said: Not sure about your second question. Displacement currents is an electric phenomenon (or a bunch of a similar phenomenon) observed in a dielectric media. It happens when electric charges swing without actually moving. For example in air, I think, it could be a periodic change in air molecules collective polarization. I don't know what could be done in order to organize it, but possible we need to tap the resonance frequency of a certain type of molecules present in the air. For example nitrogen or oxygen molecules may have some particular vibrational frequency. Possibly we may need very high frequency of a changing electric field. Possibly displacement currents may carry data or energy. This field is still poorly explored, not much data on it. Edited July 27, 2019 by Moreno Link to comment Share on other sites More sharing options...
Moreno Posted July 27, 2019 Author Share Posted July 27, 2019 On 7/25/2019 at 11:26 AM, Endy0816 said: QM requires a second standard transmission channel. What is known about radio waves quantum tunneling? It seems such effect does exist. Can radio wave tunnel between a two remote antennas with almost no attenuation? Link to comment Share on other sites More sharing options...
Strange Posted July 27, 2019 Share Posted July 27, 2019 7 hours ago, Moreno said: What is known about radio waves quantum tunneling? It seems such effect does exist. Can radio wave tunnel between a two remote antennas with almost no attenuation? The probability of tunnelling falls very rapidly with distance, which is why all the photons a receives gets have travelled through the air to get there. If you could (somehow) rely on only tunnelled photons, then the signal would be attenuated to zero. Link to comment Share on other sites More sharing options...
Moreno Posted July 27, 2019 Author Share Posted July 27, 2019 (edited) 10 hours ago, Strange said: The probability of tunnelling falls very rapidly with distance This is typical to electrons or similar elementary particles with very small de Broigle wavelength. Are you sure the same is true about radio waves? What is de Broigle wavelength of a say 1 GHz radio wave? I'm not sure we can speak about radio wave as about separate photons in this context. Edited July 27, 2019 by Moreno Link to comment Share on other sites More sharing options...
Strange Posted July 28, 2019 Share Posted July 28, 2019 1 hour ago, Moreno said: What is de Broigle wavelength of a say 1 GHz radio wave? 30 cm 1 hour ago, Moreno said: I'm not sure we can speak about radio wave as about separate photons in this context. If we can’t speak about photons then we can’t speak about tunnelling Link to comment Share on other sites More sharing options...
Moreno Posted July 28, 2019 Author Share Posted July 28, 2019 52 minutes ago, Strange said: 30 cm If we can’t speak about photons then we can’t speak about tunnelling Does it mean it will tunnel for 30 cm distance with no problems? And what about kilohertz waves? Link to comment Share on other sites More sharing options...
Enthalpy Posted August 10, 2019 Share Posted August 10, 2019 "In 50 years" doesn't fit with "cellular" and "base stations". We don't know what technology will be then. We can't suppose there will be cells and base stations. 50 years ago, there were none. Link to comment Share on other sites More sharing options...
Moreno Posted August 29, 2019 Author Share Posted August 29, 2019 What are the expectations about the price of unlimited mobile Internet when 5G network will be fully implemented? How much is it going to cost in USA or other countries? Link to comment Share on other sites More sharing options...
Moreno Posted August 29, 2019 Author Share Posted August 29, 2019 On 7/24/2019 at 5:51 AM, Strange said: Shorter distances also mean lower power. So it’s a win-win Shorter distances=higher frequency=higher power. Shorter distances=larger quantity of the base stations=higher price. Link to comment Share on other sites More sharing options...
Art Man Posted August 29, 2019 Share Posted August 29, 2019 On 7/17/2019 at 11:04 PM, Moreno said: What will wireless communications look like in 50 years? Is there any new ideas on how is it possible: I would look at whats cutting edge right now and its seems obvious. 1. Artificial Intelligence 2. Augmented Reality 3. Virtual Reality 4. Direct brain to device integration 5. Implanted chips and nanotech 6. Quantum technology - instant communications 7. Brain sensor technology (requiring no direct integration) Theres some things Im forgetting. Id say these are just the beginning. Link to comment Share on other sites More sharing options...
koti Posted August 29, 2019 Share Posted August 29, 2019 11 minutes ago, Moreno said: Shorter distances=higher frequency=higher power. Shorter distances=larger quantity of the base stations=higher price. With 5g they will have to install bts’s every few or few dozen meters (at most) to achieve the ~order of maganitude quicker download/uploads. I don’t know how this is supposed to benefit me appart from maybe more security...someones going to make a lot of money by building this whole new infrastructure. What I would love to see (quicker than 50 years from now) is a technology which would significantly bring down power consumption in mobile devices to a point in which some next level wireless charging technology could enable me to have a phone without any power source. Link to comment Share on other sites More sharing options...
Strange Posted August 30, 2019 Share Posted August 30, 2019 36 minutes ago, Moreno said: Shorter distances=higher frequency=higher power. What? You need less power if you are transmitting over shorter distance (inverse square law). Quote Shorter distances=larger quantity of the base stations=higher price. I thought we were talking mesh networks? And if there are more base stations, then they can be lower power and cheaper. You can buy a femtocell for about $100. Link to comment Share on other sites More sharing options...
Moreno Posted August 30, 2019 Author Share Posted August 30, 2019 36 minutes ago, koti said: 1) With 5g they will have to install bts’s every few or few dozen meters (at most) to achieve the ~order of maganitude quicker download/uploads. I don’t know how this is supposed to benefit me appart from maybe more security... 2) What I would love to see (quicker than 50 years from now) is a technology which would significantly bring down power consumption in mobile devices to a point in which some next level wireless charging technology could enable me to have a phone without any power source. 1) One potential advantage could be a lower cost. Once unlimited mobile internet becomes as cheap as unlimited cable internet, cables go away and everyone will have mobile internet. It means phone calls could potentially become free as everyone will use program similar to Skype to make phone calls. So, instead paying for internet+phone calls you may pay just for unlimited internet and make unlimited calls. 2) Once long distance highly efficient point to point energy transfer will become a reality (for example with help of quantum tunneling), probably both energy and data will be transfered in this way. So, battery in your phone (if any) will be used only in the case of unbelievable emergency. Link to comment Share on other sites More sharing options...
Strange Posted August 30, 2019 Share Posted August 30, 2019 10 hours ago, Moreno said: 2) Once long distance highly efficient point to point energy transfer will become a reality (for example with help of quantum tunneling) Meanwhile, back in the real world ... Link to comment Share on other sites More sharing options...
Moreno Posted August 30, 2019 Author Share Posted August 30, 2019 25 minutes ago, Strange said: Meanwhile, back in the real world ... But I am talking about the future... Link to comment Share on other sites More sharing options...
Strange Posted August 30, 2019 Share Posted August 30, 2019 7 minutes ago, Moreno said: But I am talking about the future... "Point to point energy transfer using quantum tunnelling" will never be a thing. Devices harvesting enough energy from the environment might be possible in future. Link to comment Share on other sites More sharing options...
Moreno Posted August 30, 2019 Author Share Posted August 30, 2019 Quote "Point to point energy transfer using quantum tunnelling" will never be a thing. Why? Link to comment Share on other sites More sharing options...
Enthalpy Posted September 21, 2019 Share Posted September 21, 2019 (edited) On 7/18/2019 at 1:44 PM, Moreno said: What about communication which is based on totally new physical principles? Can we use something different than microwaves? Sure. Over a short distance, a magnetic field lets communicate. Advantage: it doesn't interfere at longer distance. Disadvantage: only few decametres. Or by light if we accept to be in direct sight. Exists to spread the Internet access in a room. What shall "new" physical principles be? Technology can develop "new" toys without needing new physics. Physics can explain new effects without discovering new forces. Problem of the whole topic is, we ignore what technology will look like in 50 years. Nobody predicted Internet so long in advance. Many thousand people think long and hard to make new toys available in 10 years, I don't believe we'll find in 5 min the ones available in 50 years. On 7/19/2019 at 6:55 AM, Moreno said: I think one of the largest problems with modern radio transmitters is that radio wave radiated omnidirectionally. It makes 99.99 % of all the energy lost in vain and only 00.01% of energy reach the cell tower. It would be good to invent something that would allow almost 99% of energy be transferred between the sender and the receiver. It could be helpful for peer to peer networks two. Possibly it could resemble some long-distance electromagnetic resonance? Besides the fixed directional antennas pointed by Sensei, there are antennas with aperture synthesis. They form transmission and reception beams by combining many small elements with the proper phase and optionally amplitude. These can easily adapt to a moving target and were developed for radars. The serve increasingly for Wifi presently. A limit is diffraction. It takes an antenna many wavelength wide and high to concentrate a beam at a target many wavelength away. 0.1m microwaves are inefficient for that, and directional antennas can only reduce the waste. Light is better, and several satellites communicate per laser presently. Cell phones are too small to make good aperture synthesis (or beam forming) with microwaves. At best, they could have few antennas close to an other and radiate in all dimensions like a small dipole. More efficient pattern, but the antennas themselves get less efficient. On 7/24/2019 at 10:52 AM, Moreno said: I think wireless technology moves in the direction opposite from desirable, in some aspects. The frequencies mobile devices use constantly increase, but it requires to reduce the distance between communicating nodes. A compact walkie-talkie device which works in 60-100 MHz range allows to communicate in 60 km range without problems. A mobile phone which works on 2 GHz frequency requires less than 500 meters distance to a cell tower. The range varies in a complicated fashion with the frequency. Between some 3MHz-20MHz you can reach the antipodes. Over 30MHz you're more or less limited to the horizon. But in direct sight like in outer space, it you can direct big antennas properly, higher frequencies give a more efficient transmission. That's one reason for ever higher frequencies. Though, atmospheric absorption limits to about 40GHz on Earth, with an other window around 94GHz. On 7/25/2019 at 1:45 AM, Moreno said: Can the "displacement currents" in air or ground be ever useful to transmit data or energy? What if we use the resonant frequency of air molecules? To cause polarization waves of air molecules? Can some quantum mechanics be useful for data transmission? For example, can we create some kind of "quantum coupling" between two antennas? Displacement current serves in every electromagnetic wave. It's dE/dt that relates with curl(B). It's also what lets ceramic (or "dielectric") antennas work in cell phones. There is some misunderstanding about that, but vacuum's displacement current at an antenna creates no distant EM wave, while the displacement current added by a dielectric results from charge movement and these radiate. Resonance of air molecules creates losses. This limits long-range transmissions to 40GHz. Several cutoffs exist that relate to moisture, oxygen and more. Do you mean tunnelling by "quantum coupling"? Two coils are coupled by tunnelling. Capacitive coupling too. Optical fibres coupled by proximity as well. Call that "virtual photons" to make it pedantic. Problem is, tunnelling fades quickly with the distance. It's the superiority of an electromagnetic wave that it propagates, while the tunnelling electrostatic or magnetostatic fields fade very quickly. On 7/28/2019 at 3:03 AM, Moreno said: Does it mean it will tunnel for 30 cm distance with no problems? And what about kilohertz waves? Tunnelling of radiowaves is common in apparatus. Some have two coupled parallel propagation lines to measure only the power propagating in one direction. Tunnelling goes farther at lower frequencies but the antennas get inefficient. A typical coupling distance by magnetic of electric fields is the size of the coil or electrodes. Like in RFID, you get 15cm range from a D=30cm bas antenna and a chipcard-sized antenna. On 8/30/2019 at 1:58 PM, Strange said: "Point to point energy transfer using quantum tunnelling" will never be a thing. Devices harvesting enough energy from the environment might be possible in future. RFID does exactly that, power a chipcard over the magnetic field, which is tunnelling. How much power do you hope to find in the environment? A wire gets some -60dBm from strong FM-band transmitters nearby, that's 1nW. Other means, other source...? Edited September 21, 2019 by Enthalpy Link to comment Share on other sites More sharing options...
Moreno Posted September 25, 2019 Author Share Posted September 25, 2019 On 9/21/2019 at 11:09 AM, Enthalpy said: Do you mean tunnelling by "quantum coupling"? Two coils are coupled by tunnelling. Capacitive coupling too. Optical fibres coupled by proximity as well. Call that "virtual photons" to make it pedantic. Problem is, tunnelling fades quickly with the distance. It's the superiority of an electromagnetic wave that it propagates, while the tunnelling electrostatic or magnetostatic fields fade very quickly. It seems under certain physical conditions tunneling can happen through barriers of any width (any distance). https://en.wikipedia.org/wiki/Klein_paradox Link to comment Share on other sites More sharing options...
Moreno Posted April 30, 2020 Author Share Posted April 30, 2020 What is practically known about radio soliton communications? For example, how much would it allow to increase band width and reduce interference? https://www.nist.gov/news-events/news/2010/09/new-wave-spin-soliton-could-be-hit-cell-phone-communication Quote For example, these systems can efficiently generate soliton signals and can perform the nonlinear signal separation of multi-soliton carriers necessary for multiplexing and demultiplex ing multiple users in a potential soliton wireless communications context. https://dspace.mit.edu/bitstream/handle/1721.1/4154/rle-tr-599-35197933.pdf?sequence=1 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now