renamed article Kris de Decker + removed the wrong caption of img 6
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@ -14,7 +14,7 @@ ireless internet access is on the rise in both modern consumer societies and in
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In rich countries, however, the focus is on always-on connectivity and ever higher access speeds. In poor countries, on the other hand, connectivity is achieved through much more low-tech, often asynchronous networks.
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.]({static}/images/Kris-de-decker_how-to-build-a-low-tech-internet-1.png)
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.]({static}/images/kris-de-decker_how-to-build-a-low-tech-internet-1.png)
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While the high-tech approach pushes the costs and energy use of the internet [higher and higher](https://www.lowtechmagazine.com/2015/10/can-the-internet-run-on-renewable-energy.html), the low-tech alternatives result in much cheaper and very energy efficient networks that combine well with renewable power production and are resistant to disruptions.
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@ -34,7 +34,7 @@ Most low-tech networks are based on WiFi, the same technology that allows mobile
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The longest unamplified WiFi link is a 384 km wireless point-to-point connection between Pico El Águila and Platillón in Venezuela, established a few years ago.[^3][^4] However, WiFi-based long distance networks usually consist of a combination of shorter point-to-point links, each between a few kilometres and one hundred kilometers long at most. These are combined to create larger, multihop networks. Point-to-points links, which form the backbone of a long range WiFi network, are combined with omnidirectional antennas that distribute the signal to individual households (or public institutions) of a community.
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Long-distance WiFi links require line of sight to make a connection -- in this sense, the technology resembles the 18th century [optical telegraph](https://www.lowtechmagazine.com/2007/12/email-in-the-18.html).[^5] If there's no line of sight between two points, a third relay is required that can see both points, and the signal is sent to the intermediate relay first. Depending on the terrain and particular obstacles, more hubs may be necessary.[^6]
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@ -46,7 +46,7 @@ Distribution nodes usually consist of a sectoral antenna (a small version of the
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To provide users with access to the worldwide internet, a long range WiFi network should be connected to the main backbone of the internet using at least one "backhaul" or "gateway node". This can be a dial-up or broadband connection (DSL, fibre or satellite). If such a link is not established, users would still be able to communicate with each other and view websites set up on local servers, but they would not be able to access the internet.[^10]
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## Advantages of Long Range WiFi
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@ -63,7 +63,7 @@ Long range WiFi also has low operational costs due to low power requirements. A
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The first long range WiFi networks were set up ten to fifteen years ago. In poor countries, two main types have been built. The first is aimed at providing internet access to people in remote villages. An example is the Akshaya network in India, which covers the entire Kerala State and is one of the largest wireless networks in the world. The infrastructure is built around approximately 2,500 "computer access centers", which are open to the local population -- direct ownership of computers is minimal in the region.[^13]
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Another example, also in India, are the AirJaldi networks which provide internet access to approximately 20,000 users in six states, all in remote regions and on difficult terrain. Most nodes in this network are solar-powered and the distance between them can range up to 50 km or more.[^14] In some African countries, local WiFi-networks distribute internet access from a satellite gateway.[^15][^16]
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A second type of long distance WiFi network in poor countries is aimed at providing telemedicine to remote communities. In remote regions, health care is often provided through health posts scarcely equipped and attended by health technicians who are barely trained.[^17] Long-range WiFi networks can connect urban hospitals with these outlying health posts, allowing doctors to remotely support health technicians using high-resolution file transfers and real-time communication tools based on voice and video.
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An example is the link between Cabo Pantoja and Iquitos in the Loreto province in Peru, which was established in 2007. The 450 km network consists of 17 towers which are 16 to 50 km apart. The line connects 15 medical outposts in remote villages with the main hospital in Iquitos and is aimed at remote diagnosis of patients.[^17][^18] All equipment is powered by solar panels.[^18][^19] Other succesful examples of long range WiFi telemedicine networks have been built in India, Malawi and Ghana.[^20][^21]<p/>
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@ -81,7 +81,7 @@ Despite the lack of reliable statistics, community networks seem to be rather su
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Guifi.net provides internet access to individuals, companies, administrations and universities. In principle, the network is installed, powered and maintained by its users, although volunteer teams and even commercial installers are present to help. Some nodes and backbone upgrades have been succesfully crowdfunded by indirect beneficiaries of the network.[^8][^22]
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## Performance of Low-tech Networks
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@ -92,7 +92,7 @@ However, the low-tech networks that distribute internet access to a large user b
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Therefore, the worst-case average bandwidth available per machine is approximately 1.9 kbps, which is slow even in comparison to a dial-up connection (56 kbps). And this can be considered a really good connectivity compared to typical rural settings in poor countries.[^26] To make matters worse, such networks often have to deal with an intermittent power supply.
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Under these circumstances, even the most common internet applications have poor performance, or don't work at all. The communication model of the internet is based on a set of network assumptions, called the TCP/IP protocol suite. These include the existence of a bi-directional end-to-end path between the source (for example a website's server) and the destination (the user's computer), short round-trip delays, and low error rates.
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@ -116,7 +116,7 @@ Delay-tolerant networking can take surprising forms, especially when they take a
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Examples are DakNet and KioskNet, which use buses as data mules.[^30][^34] In many developing regions, rural bus routes regularly visit villages and towns that have no network connectivity. By equipping each vehicle with a computer, a storage device and a mobile WiFi-node on the one hand, and by installing a stationary WiFi-node in each village on the other hand, the local transport infrastructure can substitute for a wireless internet link.[^11]
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Outgoing data (such as sent emails or requests for webpages) is stored on local computers in the village until the bus comes withing range. At this point, the fixed WiFi-node of the local computer automatically transmits the data to the mobile WiFi-node of the bus. Later, when the bus arrives at a hub that is connected to the internet, the outgoing data is transmitted from the mobile WiFi-node to the gateway node, and then to the internet. Data sent to the village takes the opposite route. The bus -- or data -- driver doesn't require any special skills and is completely oblivious to the data transfers taking place. He or she does not need to do anything other than come in range of the nodes.[^30][^31]
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