Twisting Radio Waves Won’t Increase Wireless Capacity
Emerging technologies often tend to hit engineering roadblocks that hamper them from being useful. In the past year, there have been claims that “twisting” radio waves could significantly enhance the capacity of wireless bandwidth. Exploiting orbital angular momentum (OAM) is allegedly a unique method to transmit a larger amount of bytes. There are tons of portable devices available. Finding new ways to enhance their performance is desirable. Consumers have a voracious appetite to download media, but the laws of physics put a damper on how much data appliances can gather. The press releases pertaining to the novel discovery seemed too good to be true. A few researchers were making several ambitious statements about obtaining a huge number of different channels and an order of magnitude improvement. There are reasons to be skeptical of such proclamations. Scientists from Lund University in Sweden have published a paper, which indicates that the assertions relating to this breakthrough may be overblown.
The academics compared OAM to a more traditional technique called multiple-in-multiple-out (MIMO). What they found was that the some OAM states overlap with the eigen-modes that are derived from the MIMO theory. MIMO communication already exploits OAM states whenever the configurations call for it. The OAM is apparently a sub-class of a MIMO that uses specific kinds of circular antenna arrays.
Going over a certain length, the gains afforded to various orbital angular momentum states decrease quickly. This means that for telecommunications, most of the channels are useless. There are no additional upgrades to the wireless capacity. Only one OAM state is still helpful when traversing lengths greater than a thousand times the Rayleigh distance.
The researcher concludes that this type of connection has the ability to deliver a higher rate over short distances. Perhaps if the walls of your house had particular types of antennas, it could enable your mobile computers to receive more information. Unfortunately, this route is optimal only under select conditions. Basically, he says that the OAM does not really bring anything new to the table. If you were expecting to be able to stream movies to your next generation iPhone at a faster pace, you might be disappointed that this fails to materialize. Engineers usually find innovative solutions to issues, so this may not be the end of the story. However, it seems like this is evidence that this avenue will not live up to the hype. Hopefully, there are still other ways to boost wireless capabilities in the future.

