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See also: Ricardo (links to all my pages), WorldSpace, NoahSamara, FlashDriveContent, FlashDriveEditor, Sneakernet
This page was written by Ricardo (a nickname/username), from England:
Many people talk about 'The Digital Divide' between rich and poor countries.
In an ideal world, everyone would have full, 2-way access to the internet, and be able to choose or request exactly what information they want, or upload their own information.
In developing countries, the internet is often unaffordable, hard to access without travelling far or not available at all in a particular area.
Like a few other people, I'm looking at a number of ideas for 'Datacasting', the 1-way broadcasting of files and information.
More specifically, I'm looking at ways for Broadcasters, NGOs, Companies, Educators, Health Projects, etc, to broadcast to people in developing countries that use computers offline, but don't have internet-access.
If radio-stations could broadcast a range of useful information and files, for free, it could bridge 'half of the digital divide'.
Broadcasting files via local/national/international radio-stations would give millions of people access to a whole library of documents and to up-to-date information, for free.
The question is...
"How does someone broadcast data at zero/low-cost to the broadcaster and zero/low-cost to the listener/data-recipients?"
This page relates to my design for a system for transmitting files (a range of useful information and files) within the music audio-signal of ordinary radio stations (FM/MW/LW/SW).
It would be received on an ordinary cheap radio connected by an audio-lead to a computer.
For people on low-budgets in developing countries, a free data-boadcasting service would be like a 1-way internet. I know it's not ideal, and it's nowhere near as good as full, interactive 2-way internet access, but it would provide many people with a wide-range of free information and files for the first time.
It's a PartialSolution to a problem. As as optimist would say... "The glass is half-full, not half-empty". Even if it's only 5% as good as 2-way internet access, it's infinitely better than zero information.
The technology is nearly all software. The equipment to receive it is very cheap, just a radio and a cheap audio cable, so it should be affordable by almost anyone.
The information content doesn't have to be related to the radio-station that broadcasts it. The information could be provided by many other organisations, such as educators, health organisations, NGOs, news organisations, user-submitted content, etc. That leaves the radio-stations to do the actual transmission.
The facility could be commercial (with advertising) or non-commercial (Public Service Broadcasting or Non-Profit Organisations).
My Suggested Method of Transmission  Many existing methods of broadcasting data (called 'Datacasting'), often use expensive digital-radio equipment, that people in developing countries don't have at the moment, and can't afford to buy or wouldn't see as a high-priority to buy.
My suggested method of transmission embeds data as a quiet, inaudible sound-signal inside the audio of music radio stations, so people can receive it on a cheap $5 FM or SW analog radio, that they may already own, linked to a computer (PC or Laptop), via a 3.5mm stereo jack-to-jack audio cable.
There are many choices for the exact signal format for the hidden data sounds. It could be as simple as 2 tones, at 2 different frequencies for binary 1 or 0, or much more sophisticated, like the analog watermarking of music that companies do for copyright purposes.
The data could be encoded in slow-time into MP3 files of pre-recorded programs or songs, or mixed in real-time into the transmitted music/speech.
Signal-Processng Software would filter and extract the data sound-signal from the music, convert it to bits and bytes, then write the data to files on the computer. The software doesn't exist yet, but it's fairly simple. The project just needs a bit of software development by a university, a lab or some people from an open-source group on the internet.
For details of the system, see the link further down this page to my OLPC Wiki article.
Unique Selling Point The real selling point of this idea is that, for the broadcaster, 'It doesn’t need a new radio-station license or antenna etc to transmit information', which would cost a lot of money. The data gets a 'free ride' on existing radio-stations.
For the users who receive data, it's also very cheap. It's nearly all software. If the user already owns a radio, then they just need to buy a 3.5mm stereo jack-to-jack audio cable for a few pounds/dollars, to link the radio to the PC sound-card input. A cheap USB FM Radio is an alternative.
Note - This transmission of music-with-embedded-information is all within the analog audio signal (music or speech). This is NOT 'Digital Radio'. It doesn't matter whether the radio station is using old analog FM/LW/MW/SW transmission equipment, the same type that radio-stations have used since the 1920s and 30s.
The signal can survive being relayed through several stations. For example, when the BBC World Service transmits worldwide from the UK, then local FM Stations re-broadcast the programmes.
It doesn't matter whether the audio passes through satellite up-links/downlinks or via internet radio streams or analog/digital methods of transmission. It's all in the sound.
The higher-level 'content management' design decisions ("What shall we transmit?") and the software are pretty-much unrelated to the 'hidden sounds' data signal-format.
The content could be any type of file; web-pages, eBooks, group emails, photos or anything. The subject-matter may be related to the radio programme or radio-station or not. It could be data belonging to other data-providers (educators, NGOs, etc).
Any up-to-date information could be a rolling carousel of web-pages (like BBC Teletext, but of local/subject-specific interest). Files of long-lasting value could also be transmitted, such as eBooks or learning-material for a school library, health leaflets, etc. The news pages and library of files would be cached on the user's PC, and accumulate into a useful library over time.
Bandwidth The system has quite a low Bandwidth (data-capacity per day), but files can be stored and build up into a useful library of information over many months, and it's free.
Also, the user can tune-into many different radio-stations, to receive different types of information.
Who would use it? People/Businesses/NGOs in developing countries. It may be a small sub-set of the population for a start - "Those people who have a PC or Laptop, but use it offline, because the internet is too expensive or unavailable in their area".
However, if free data-streams were broadcast by local FM stations, I think more people would start using it, with a wider variety of new devices with the decoder built in, not just conventional PCs and Laptops. For example, FM Radios with a small LCD display, phones with an FM radio, etc.
Datacasting also has applications in richer/intermediate-income countries, in isolated areas, mountainous areas, islands, small boats at sea, etc.
Full Details I first published the idea in 2007 on the 'One Laptop Per Child' public Wiki site, on the "Radio and broadcast" page.
My OLPC Wiki posting has more detail, and some diagrams.
The "Radio and broadcast" page contains ideas by several contributors to the OLPC Wiki, in different sections of the page. Please see my Section 7, called 'Embedding Data as Hidden-Sounds within a Radio-Station’s Audio-Stream'.
 http://wiki.laptop.org/go/Radio_and_broadcast (section 7)
If you want to discuss this idea with me, I check the Comments section below from time to time, but it's better to send me an email on ricardoolpc@yahoo.co.uk
See Also Other projects to bridge The Digital Divide (Airjaldi, Wizzy Digital Courier, Daknet, KioskNet, etc).
http://wiki.laptop.org/go/Sneakernet#Further_reading
Sun, 22 Mar 09 05:55:10 +0000 Andrius Kulikauskas: Hi Ricardo! Thank you for your awesome work. Greetings from London! I wish I could entice you to meet me, Franz, Samwel and others! As you wish... Peace.
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