FabFi is an open-source, FabLab-grown system using common building materials and off-the-shelf electronics to transmit wireless ethernet signals across distances of up to several miles. With Fabfi, communities can build their own wireless networks to gain high-speed internet connectivity---thus enabling them to access online educational, medical, and other resources.
Introduction[edit | edit source]
In January 2009, the Jalalabad FabLab demonstrated the capability of the FabFi system by bringing high-speed internet to a village, hospital, university, and a non-governmental organization in Jalalabad, Nangarhar Province, Afghanistan. These low-cost, locally-produced networks can be easily spread across isolated villages and towns, placing them in touch with the outside world and facilitating socio-economic development from the ground up. After a month of intensive training and practical experience, the Jalalabad FabLabbers are well on their way to self-sufficiency in the maintenance and expansion of their own local network, with a long list of locations in line to be linked up.
Jalalabad's longest link is currently 2.41 miles, between the FabLab and the water tower at the public hospital in Jalalabad, transmitting with a real throughput of 4.5Mbps (compared to 22Mbps ideal-case for a standards-compliant off-the-shelf 802.11g router transmitting at a distance of only a few feet). The system works consistently through heavy rain, smog, and a couple of good-sized trees.
Project Summary (as of Oct 5, 2011)
- Production Networks actively deployed in four locations across two countries
- 45 remote FabFi nodes are currently deployed in and around Jalalabad, Afghanistan
- Longest link is 6,000m (3.72mi)
- Data throughput 11.5Mbps
- System extensible by anyone
- Materials to make an endpoint link are $60US and available locally
- 50 remote FabFi nodes are currently deployed across three sites
- Longest link is 3,500m
- 6-hop Data throughput across 2,500m, > 30Mbps
- System provides WiFi directly to end-users
Sytem integrates user accounting and management[edit | edit source]
FabFi has been featured in numerous print and online media articles, including the New York Times, and major tech blogs such as Gizmodo.com, BoingBoing.net, and NOS news in the Netherlands.
Fabfi Development[edit | edit source]
As 2011 comes to a close, the Fabfi team is working on an entirely new architecture. Fabfi version 5 will be a native IPv6 system with multi-radio devices, 802.1x authentication, integrated billing and cloud management. We envision this system as scalable to thousands of user-installable nodes. Apologies for any gaps in documentation while we're tying up the loose ends. Field testing is underway, and a proper release is expected in Q1 2012.
FabFi Kenya[edit | edit source]
In the summer of 2010, the Fab team set out to show that Fabfi could be both reliable and sustainable. Choosing Kenya as a pilot site Fabfolk seeded three Fablab students with the hardware to begin deploying a network as a community-operated business. Over the course of the next six months, the team updated the FabFi software and stood up three pilot sites, with the goal of covering their expenses and labor within one year. First experiences on the ground in Kenya suggest that community networks like this one fill a service and support niche that large providers ignore. Our Kenyan operators are building strong personal relationships with the people they serve, often performing other technical services beyond simple networking support. Feedback from users is overwhelmingly positive. Our Kenyan collaborators are providing a paid internet service using the Fabfi platform under the name JoinAfrica. For the most current info on Fabfi Kenya, check out the JoinAfrica website.
FabFi Afghanistan[edit | edit source]
In January 2009, the Jalalabad FabLab demonstrated the capability of the FabFi system by bringing high-speed internet to a village, hospital, university, and a non-governmental organization in Jalalabad, Nangarhar Province, Afghanistan. These low-cost, locally-produced networks can be easily spread across isolated villages and towns, placing them in touch with the outside world and facilitating socio-economic development from the ground up. After a month of intensive training and practical experience, the Jalalabad FabLabbers are well on their way to self-sufficiency in the maintenance and expansion of their own local network, with a long list of locations in line to be linked up. Jalalabad's longest link is currently 2.41 miles, between the FabLab and the water tower at the public hospital in Jalalabad, transmitting with a real throughput of 11.5Mbps (compared to 22Mbps ideal-case for a standards-compliant off-the-shelf 802.11g router transmitting at a distance of only a few feet). The system works consistently through heavy rain, smog, and a couple of good-sized trees.
In FabLabs, technology brings people and ideas together. FabFi embraces this same principle. The public hospital, which houses the endpoint of FabFi Afghanistan's longest link, has become a shared community resource, providing downlinks to a growing number of locations in the city center. The shared infrastructure facilitates communication between FabFi users all over the city as they collaboratively grow and maintain the network. The FabFi user group is learning valuable skills that will soon allow them to generate revenue for themselves and the Lab by building, installing, and maintaining FabFi links as part of a "FabFi Club" at the FabLab. Pictured below are the two endpoints of the water tower link, FabLab on the left, water tower on the right.
Here's Steve A. with Said-Jalal from Bagrami looking very satisfied after successfully setting up the Water Tower link (2.41mi).
A Fab Future[edit | edit source]
Because FabFi is fundamentally a technological and sociological research endeavor, it is constantly growing and changing. Over the coming months expect to see infrastructure improvements to improve stability and decrease cost, and added features such as meshing and bandwidth aggregation to support a growing user base. In addition to network improvements, there are plans to leverage the provided connectivity to build online communities and locally hosted resources for users in addition to MIT OpenCourseWare, making the system much more valuable than the sum of its uplink bandwidth.
FabFi Technical Summary[edit | edit source]
Overview[edit | edit source]
FabFi is a user-extensible long-range point-to-point and mesh hybrid-wireless broadband transmission infrastructure. It is based on the simple idea that a network of simple, intelligent, interconnected devices can create reliable networks in unstable environments. We use simple physics to make low-cost devices communicate directionally for very long distances (physics is cool!), and flexible configurations to adapt to a large variety of conditions.
For extreme conditions, we mount commercial wireless routers on fabbed RF (Radio Frequency) reflectors with a wire mesh surface that redirects the RF energy. Reflector gain depends on the materials used and the size of the reflector, but has been measured as high as 15dBi with some of the current designs.
A single wireless link in the FabFi system consists of two reflectors with attached wireless routers. Similarly, two routers can be linked with a wired connection. A single router can be linked to both wired and wireless connections at the same time. The system is configured for individual links to be combined in numerous ways, creating links that cover very long distances or service many users in a small area. A key component of this linking is called "meshing". A mesh network is one where any device can be connected to one or more other neighbor devices in an unstructured (ad-hoc) manner. Mesh networks are robust and simple to configure because the software determines the routing of data automatically in real-time based on sensing the network topology. Traditional mesh networks are limited in scale because they rely on a single radio, wireless-only connections and omnidirectional antennas. By using directed wireless links and wired transfers whenever possible, the Fabfi system is optimized for building very large-scale static (as opposed to mobile) mesh networks. With Scale comes the potential for robust digital communities within a region without dependence on high-bandwidth local uplinks, which are expensive and unavailable in many places. Check out the animation for a little more detail (2MB, might take a while to load):
How Reflectors work[edit | edit source]
FabFi reflectors use the property of parabolic shapes (Y=cX^2) that a when a vector travelling perpendicular to a parabola's directrix hits the surface of the parabola it is reflected to the parabola's focal point. (see Mathworld for more on this...) By attaching a RF reflective material such as window screen or chicken wire to a frame that forms the shape of a parabola in three dimensions and then attaching our wireless router to the reflector at the focal point we can precisely concentrate and direct the RF energy coming from the router in transmission and efficiently collect RF energy from the paired router in reception.
Building Reflectors[edit | edit source]
An essential component of the FabFi system is its flexibility to be implemented with whatever materials are locally available. All that's required is the ability to print out a 2D design file and create the pieces out of whatever material you can find. If you have a Fab Lab, you can use a laser cutter or CNC wood router to create reflectors directly from wood, metal, or acrylic, but there's no reason they can't be molded from clay, carved from stone, or chiseled out of a block of ice as long as there's a way to attach a metallic RF reflective surface to the front.
Three different reflector designs were implemented in Jalalabad during the initial deployment in January 2009: a large 4' wooden version, a 2' wooden version, and an 18" acrylic version. Reflective surface materials included chicken wire, woven stainless steel mesh, and window screen. Needs in the field subsequently drove the development of modified reflector designs with integrated weatherproofing and and fastener-less assembly. These new designs debuted in the summer of 2010.
It was not long afterward, however, that network users began designing and building their own reflectors out of locally sourced scrap materials. While still in need of significant refinement, these reflectors are clear physical signs of technology transfer and local human-capital development in the technology domain. They also cost less than $3US!
Routers and Firmware[edit | edit source]
FabFi uses an open source 3rd party firmware called OpenWRT on all of its routers. Taking advantage of OpenWRT's Linux-based flexibility, FabFi devices can run a wide range of network monitoring and self-diagnostic tools. The current system supports real-time network monitoring, local web caching centralized access control, user management and usage tracking (for billing). All of this is performed on devices costing $50-$100USD. Automated configuration has been steadily improving since the bygone days of the FabFi 1.0 release. We now support multiple routers across multiple fabfi distributions, and have the ability to configure networks with 802.11n speeds. Power In developing places, reliable power is an ongoing challenge. Conveniently, all of our currently supported devices will run on 12VDC, and can be easily powered directly from a car or small engine battery. A car battery and a couple of inexpensive chargers function as reliable UPS devices on two major distribution hubs in the Jalalabad network, powering a bank of routers for nearly two days without city power. In Kenya, we have designed a "node in a box" that provides UPS, mounting and weatherproofing to every node in the network, supporting mains or solar power. Future development is planned for a bare-bones 12V-12V UPS that can be integrated into installations by plugging the provided 100-240VAC switching power brick into the fabbed UPS and the UPS into the router. Wind and other locally harvested powered charging circuits are a parallel FabLab project. The Fab Future Despite the cobbled-together aesthetic, Fabfi has proven incredibly reliable in Afghanistan's harsh climate (it reaches 130degF in Jalalabad in the summer with regular sandstorms). Beginning in the summer of 2010, we have expanded the fabfi system to provide direct wireless access to client devices and have been running a community-scale wifi ISP. In more than two years of deployment, we can still count the hardware failures on one hand. To our surprise, the biggest challenge so far has been to uplink bandwidth. While many countries tout "mobile broadband" as the solution to universal access problems, the ground truth in most places is that mobile devices alone do not provide sufficient performance (or affordable enough prices) to be viable without some help. In Kenya, FabFi provides a value-added service to communities where mobile connectivity is the only means of access by decreasing the data throughput per user and making it possible for providers to buy bandwidth in bulk.