There are three mainstream data transfer methods as of now: the radio waves; copper/fiber conductor; and Bluetooth. The latter has a very small range and is too slow for data transmission and hence can be dismissed. The fiber conductors too need physical wires to be placed all over the country to be connected. It is possible but it is not feasible to connect most of the sub-urban areas and especially the rural areas lying far off the main cities and hence cannot be considered a good medium if we are to think about long-term data transmission.
Microsoft has been trying to use the TV signals’ whitespace (space left between two bandwidths) for providing Internet to remote areas. While it is a good idea, I guess if it pays attention to data over sound, many remote areas will have a better coverage. Read on to know how.
Radio Waves and WiFi are harmful
GPS and Wi-Fi employs radio waves. While Wi-Fi has limits, radio waves don’t and that is why they are used for GPS. They are present everywhere and can travel fast to any area provided there are not many physical obstructions. Plus they can transmit in all directions and hence are popular for broadcasting. But radio waves are harmful. Some alternative must exist that can get us rid of harmful cellular waves and Wi-Fi signals. I was following use of light (photons) as a carrier for data but there has been no breakthrough as yet. But I came across a number of research papers when I decided to look into sound as a carrier for data and this page shares my understanding of the research.
Send Data over Sound – Advantages
To begin counting the advantages when you send data over sound, they are not harmful to living beings. Ultra high frequencies (inaudible to human ears may be harmful but I do not know how harmful they can be). Lower frequencies are much better – they won’t harm humans and can travel much farther owing to larger amplitudes. Like radio waves, they too travel in all directions and can be used easily for broadcasting.
The negative that I see is that they sound waves need a carrier for themselves – air, water, metal conductors so cannot be used in space or vacuum. That’s the only drawback and hence they may not be useful for GPS. Other than that, they can be perfect carriers for data without harming anyone with dangerous radiations as the radio waves and do. To know the extent of damage we are exposing ourselves to, read our article on hazards of cellphone.
Using Sound to Send Data over Sound
There can be three implementations to send data over sound. You can use amplitude modulation, phase modulation and frequency modulation. Out of all these three, amplitude modulation seems more feasible as it can be sent over low frequencies that are inaudible to human ears and thus, won’t create any humming sound or other distractions. Amplitude modulation also means sending data over longer areas as the sound waves with longer wavelength can easily bypass physical obstructions.
Since the digital data is binary, data can be easily mounted to sound waves by creating a short sound to indicate a 0 and a long sound to indicate the 1. At the receiving end, a demodulation (a modem) can be used to decode the message.
It is not that this is yet to be implemented. Companies in the area are already researching the cause to send data over sound and some have seen success though not complete. There are a number of issues, such as getting rid of additional sounds that the data may face while travelling on modulated sound waves. There may be attenuation and noise issues that have to be worked upon.
I would like to give the example of a startup called chirp (chirp.io). It uses bird sounds for transferring data. It was crowdfunded and was overfunded by 118%. They have developed a system that you can get on Google Play or for iOS. The app is not yet available for Windows phone.
It is not necessary that you need to have an audible sound. The best method to send data over sound would be to use inaudible frequencies and low amplitudes that can span buildings and other obstructions so that they can reach far off places. Of course, we’ll need repeaters at places if the distance is too long. But it will still be better than using a balloon to provide Internet as sounds are everywhere unlike the balloons that are stationary for six months and move over to other place leaving the Internet-addicted people with nothing until the balloon comes back. Hope Microsoft works on this aspect of data transmission and comes up with something revolutionary.