solution to radio-band congestion?

[zenmaster]

Odinn brought this topic up awhile back. Seems it's now gone from the forum.

We have shown experimentally, in a real-world setting, that it is possible to use two beams of incoherent radio waves, transmitted on the same frequency but encoded in two different orbital angular momentum states, to simultaneously transmit two independent radio channels. This novel radio technique allows the implementation of, in principle, an infinite number of channels in a given, fixed bandwidth, even without using polarization, multiport or dense coding techniques. This paves the way for innovative techniques in radio science and entirely new paradigms in radio communication protocols that might offer a solution to the problem of radio-band congestion.

http://www.bbc.co.uk/news/science-environment-17221490

Our experimental findings that EM OAM can be used for increasing radio transmission capacity without increasing bandwidth is likely to open up new perspectives on wireless communications and radio-based science. History tells us that Marconi invented the wireless telegraph and from that the communication world spread its branches in all directions [1]. All current radio communication services are based on various forms of phase, frequency and/or amplitude modulation of the EM radiation in the form of EM linear momentum (i.e. integrated Poynting vector or energy flux). In order that many different broadcasting stations are able to transmit simultaneously without overlapping their radio signals, Marconi suggested that the total available spectrum of radio frequencies be divided into many non-overlapping frequency subbands [23]. Now, the wide use of wireless communication has unavoidably led to the saturation of all available frequency bands, even after the adoption of artificial techniques that increase band capacity. We have experimentally shown that by using helicoidal parabolic antennae, the use of OAM states might dramatically increase the capacity of any frequency band, allowing the use of dense coding techniques in each of these new vortex radio channels. This might represent a concrete proposal for a possible solution to the band saturation problem.

Moreover, our experimental findings demonstrate that the spatial phase signature was preserved even in the far-field region and for incoherent non-monochromatic wave beams. These results open up new perspectives not only for wireless communication but also for physics and astronomy, including the possible detection of Kerr black holes in the test general relativity [21].

http://en.wikipedia.org/wiki/Angular_momentum_operator

[Plenum]

nice one zen.

[Diana]

Multidimensional radio broadcasting.

Surely there is a member out there with the expertise to play with this. Anybody? Pickle?

Sounds like you could also include some sort of dual station that utilizes entrainment.

[BrownEye]

Makes me think of fractals.

[Parsons]

I alllmost posted that link, Zenmaster, as I noticed that BBC article this morning. Very interesting stuff.

[zenmaster]

It is interesting. That group did a paper last year:

Physicists with the Institute of Ultrafast Spectroscopy and Lasers (IUSL) at The City College of New York have presented a new way to map spiraling light that could help harness untapped data channels in optical fibers. Increased bandwidth would ease the burden on fiber-optic telecommunications networks taxed by an ever-growing demand for audio, video and digital media. The new model, developed by graduate student Giovanni Milione, Professor Robert Alfano and colleagues, could even spur enhancements in quantum computing and other applications.

http://www.physorg.com/news/2011-08-phys...acity.html

And now they have the experiment to prove it works - for now, line-of-sight anyway. Actually, if it was only viable using line-of-sight, satellite communications may be able to take advantage of it.

[Parsons]

Wow zen... That REALLY works in my mind as multiplying bandwidth so many times that my $90/month Internet will be so slow it's like back when I had AOL 28.8k modem connection. That could be huge for how much data could be stored on a disc. The gadgetry market will be awesome in a year or two, should anyone care about that sort of thing after Dec 21

[zenmaster]

With 'infinite bandwidth', you could theoretically use low-frequency radio waves and multiplex data in multiple channels for fast communication at long distances (i.e. shortwave frequencies). Or provide hundreds of HDTV channels on just one global shortwave-radio frequency. Internet access, mobile communications, etc, could be cheap or free. But like free energy, could be abused.

---

physorg.com link with video:

A group of Italian and Swedish researchers appears to have solved the problem of radio congestion by cleverly twisting radio waves into the shape of fusilli pasta, allowing a potentially infinite number of channels to be broadcast and received.

http://www.physorg.com/news/2012-03-past...enice.html

[zenmaster]

Research from Boston University and USC promises breakthrough in internet bandwidth
As rapidly increasing demand for bandwidth strains the Internet's capacity, a team of engineers has devised a new fiber optic technology that promises to increase bandwidth dramatically. The new technology could enable Internet providers to offer much greater connectivity -- from decreased network congestion to on-demand video streaming. Described in the June 28 issue of the journal Science, the technology centers on donut-shaped laser light beams called optical vortices, in which the light twists like a tornado as it moves along the beam path, rather than in a straight line.

http://esciencenews.com/articles/2013/06....bandwidth