Internet: Difference between revisions
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Projects to provide communications using internet and non-internet means. |
Projects to provide communications using internet and non-internet means. |
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* http://www.nilshettich.com/olpcblog/ Blog about asynchronous internet |
* http://www.nilshettich.com/olpcblog/ Blog about asynchronous internet connection for OLPC school-servers in Latin America using drive-by wifi vehicles. |
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===Summaries of other data-communication technologies=== |
===Summaries of other data-communication technologies=== |
Revision as of 09:38, 24 September 2007
This page is for topics related to internet-access for the One Laptop Per Child project schools and the technologies that could be used, including regular dial-up or broadband and other methods.
Internet connectivity
Although OLPC itself is assuming that there won't be connections in many places, some laptops will be deployed in cities that have some type of Internet connectivity, even if it is more expensive and lower bandwidth than what Americans are used to.
OLPC is selling Laptops to governments. The governments will have to decide what Internet connections they can afford to include in the package they provide to schools.
OLPC project's role
Since the OLPC is primarily an educational project, we are less concerned with providing Internet access to kids and more concerned with providing a laptop that is capable of networking locally. Since both the Internet, and the OLPC laptop use the standard IP protocols, there are numerous ways in which schools, towns and countries can extend connectivity beyond the built-in mesh network.
Child friendly internet
We expect that most countries will not want to just dump the kids onto the global Internet, but will want to build their own Internet that provides a rich variety of resources targetted to children and available in their own language.
Ways of linking schools to the outside world
Standard internet-access methods
See Wikipedia: Internet - Internet access for an overview of various standard internet-access methods.
Some of the common methods are :-
- Dial-up (Landline)
- High-speed Dial-Up (with web-page compression, filtering and caching)
- Broadband (DSL or ADSL via Landline, Cable, Fibre, Mobile-phone)
- 3G Mobile-phone
- Wi-Fi
- WiMAX
- Satellite Internet Access
- Wireless Community Networks (using Wi-Fi)
Pages for other data-communication technologies
Some pages on this wiki discuss ways of extending the reach of the mesh network:
- Motoman - File delivery by Wi-Fi enabled motorbikes.
- UUCP - Unix to Unix CoPy - File transfer via dial-up modems, etc.
- MHP to laptop interface possibility - Digital Video Broadcasting - Multimedia Home Platform (Sat or TV download and/or Return Channel).
- Radio and broadcast - Shortwave radio, short/long distance Wi-Fi, Satellite, Embedding data in the audio of music radio broadcasts, etc.
- Sneakernet - Email/file delivery on physical media, such as USB Flash Drive, CD or DVD.
- Optical data link - Connecting two buildings up to 1.4KM/0.87 Miles apart via an optical infra-red LED data link at 10Mbps.
- Barcode file transfer - A method of transferring 2000+ bytes of data for an email message, information or software, in a 2-D Barcode. They can be printed on paper-letters, newsletters, circulars, etc.
Communication projects for OLPC Schools
Projects to provide communications using internet and non-internet means.
- http://www.nilshettich.com/olpcblog/ Blog about asynchronous internet connection for OLPC school-servers in Latin America using drive-by wifi vehicles.
Summaries of other data-communication technologies
The following collection is some random ideas that have been proposed, relative to Internet connectivity.
- Some places, mainly in cities in the less poor countries, will have high-capacity landlines at reasonable costs.
- Some places will have low-capacity landlines available at reasonable costs.
- Many more places will have low capacity landlines available but the costs will be prohibitive for using the Internet in the same way an American school might use it.
- There is technology, and NGOs such as SFLAN and BARWN ready to deliver it, for broadband point-to-point wireless connections. BARWN has a link across San Francisco Bay connecting its free network in San Francisco to Berkeley and Oakland. SFLAN technology has been deployed all across Bhutan. However, this only addresses regional connectivity, i.e. connecting towns within a country. Nevertheless, since the prime users of the laptops will be kids speaking only their native language, this kind of localized Internet will supply 95% of their needs.
- WiMax technology will offer considerably higher bandwidth at considerably lower cost over a much larger area per transmitter. WiMax has a service area of 30 miles (50 km) radius. There are early announcements of nation-scale WiMax networks in the US and Pakistan, at an estimated cost of about $10 per person. We may expect to hear of many more.
- Satellite connections are normally the most expensive, particularly in Africa where there is insufficient market competition. However, SES Global] is offering free satellite connections for OLPC. That means that schools need a VSAT terminal to connect. They start at about $1000.
- Wifi hotspots or wimax rollouts could be funded in some areas by the passing tourist trade through subscriptions.
- Intermittent connections can be made using dial-up links, and variations of FidoNet and Sneakernet. FidoNet depends on the existence of phone lines with reasonable night-time rates. Each server in the net calls a few of its nearest neighbors at night to exchange e-mail and other files. Nationwide propagation takes a few days. Sneakernet simply means taking data on removable media or portable computers from one computer to another. The data rate on transferring a single rewritable CD by walking from one village to another once a day is 700 MB / (24 hrs/day * 3600 sec/hr) = 8100 bytes/sec = 64.8 Kbps, somewhat more than a 56K modem.
- Taking ten or a dozen CDs to different villages by bicycle or motor scooter, or even by bus, multiplies the data rate accordingly. Using rewritable DVDs multiplies it again. USB capable DVD recorders are available for under $100.
- Bhutan has been experimenting with delivery of e-mail to villages by the postal service using Simputers, over a wireless national network built by Clif Cox of SFLAN.
- The Wizzy Digital Courier system in South Africa and elsewhere connects schools with no internet connection using USB Flash drive Sneakernet, UUCP off-peak dial-up, etc.
- First Mile Solutions - DakNet uses Mobile Access Points (Wi-Fi Vehicles). They provide a service with data delivery by Wi-Fi enabled motorbikes and buses. They visit villages and transfer data to/from Wi-Fi enabled kiosks. Local people use the kiosks for email, SMS, voicemail, web searches, and other local products and services. The villagers can buy and sell products (medicines, craft-items, seeds, fertilizers, books, cosmetics, music) through the kiosks. The goods are delivered to them on the same vehicles as the data. This social-enterprise company was set up by people from MIT to provide low-cost data services, at prices as low as $1 per user per month. ‘Dak’ is a Hindi word for ‘Post’ or ‘Postal’.
- KioskNet - Village kiosks for information services, email, etc, served by a Wi-Fi vehicle. Open-source software to use or adapt. Each kiosk costs only $100 to $700.
- United Villages Their website says "United Villages provides villagers in Asia, Africa, and Latin America with a digital identity and access to locally-relevant products and services using our low-cost, store-and-forward "drive-by WiFi" technology. Our Mobile Access Points (MAPs) are installed on existing vehicles (e.g. buses and motorcycles) and automatically provide access for WiFi-enabled Kiosks along the roads."
- Long-distance Wi-Fi Mesh – AirJaldi, a social-enterprise provides data-delivery in India by long-distance Wireless Mesh (a chain/mesh of repeaters), following the deregulation of Wi-Fi for outdoor use. It provides file transfer at 6Mbps and VOIP (Voice-Over-IP) Telephony to 30 nodes and 2000 computers. The Airjaldi Mesh Routers use only 4 Watts, from Solar Panels.
- Very long distance Wi-Fi link - See the 'Very long distance Wi-Fi' section in Radio and broadcast. This mentions a free eBook, 'Wireless Networking in the Developing World', that covers all the technical aspects and lessons learned from trials. It also mentions a 60 US Dollar Wi-Fi link in Venezuala that transmitted over 237 miles/382 Kilometers in a single point-to-point link, a world record.
Web-access by email
In some parts of the world, there are no ISPs (Internet Service Providers) offering web-accces, just email-only access to the internet. In such cases, an Email Auto-responder, can be used to get web-pages.
Public email auto-responders like this already exist, but they are often overloaded and not working. An email auto-responder restricted to OLPC schools would be better. A private auto-responder would avoid overload and mean that additional functions could be added, to get copies of small websites, web-directories, search-engine results, eBooks, Software, learning-material, etc.
The ability to obtain web-pages would give children and teachers in these email-only areas much greater access to information and some limited hands-on experience of the World Wide Web. The service could be restricted to web-pages from a private OLPC internet for a particular country, to ensure content is suitable for children.
See the list of Open Source email auto-responder software in the 'Web access via email' section of the eBook How To Accelerate Your Internet.
Accessing the internet on slow connections
Bandwidth management
The BMO (Bandwidth Management and Optimization) Book Sprint Team website has a free eBook How To Accelerate Your Internet - A practical guide to Bandwidth Management and Optimisation using Open Source Software. It covers all aspects of getting the best performance out of a slow internet connection (Dial-Up Modem, etc). It includes configuring servers and browsers, etc, and Bandwidth Management, so that each user gets a fair share of the bandwidth on a shared connection, preventing large file-downloads, peer-to-peer file-sharing and VOIP phone calls slowing it down for everyone else.
Text-only browsing
There are various websites for accessing the web on slow connections, displaying text, not graphics. For example Aidworld/Aptivate has a website called Loband.
Web-page compression
'Web-page compression' is another way to speed-up web-browsing and reduce page load-times. If children are only allowed access to websites on a virtual-private OLPC internet, then each site can be compressed using a specialized program when it is published on the web-server. If they are accessing other people's public internet sites then some ISPs offer page-compression (advertised as a ratio of 5:1), where user's set-up there browsers to get pages via the Internet Service Provider's proxy server. If an ISP doesn't offer it, then the OLPC project could set up their own proxy server for schools to use. The web-browser requests a page, the proxy server gets it from the website, compresses it and returns it to the browser. Most browsers support open compression standards and can decompress the page. If not, plug-in software can be installed.
There are commercial programs for web-page compression, such as OnSpeed.
For more information, see WebSiteOptimization.com - HTTP Compression and Wikipedia: High-speed Dial-Up.
--Ricardo 12:53, 14 September 2007 (EDT)