WiFi
Magnetic Declination and Aligning WiFi Links
- Go to www.magnetic-declination.com and plug in your city. It will tell you your declination (in degrees). If the declination is positive, you have east declination. If the declination is negative you have west declination.
- Remember CADET (I printed a label and stuck it on the back of my compass). C=Compass T=True and ADE=Add DEclination. This means to go from Compass to True you Add DEclination.
If your Compass bearing is 100 degrees and your declination is 15 degrees (east), 100+15=115 True.
If your Compass bearing is 100 degrees and your declination is -15 degrees (west), 100+(-15)=85 True.
- To go the other way, you read CADET from right to left instead. To go from True to Compass, you do the opposite of add declination. You subtract it:
If your True bearing is 100 degrees and your declination is 15 degrees (east), 100-15=85 Magnetic
If your True bearing is 100 degrees and your declination is -15 degrees (west), 100-(-15)=115 Magnetic
- If waypoint A is where you are and waypoint B is where you're trying to point your antenna, go stand at A with your GPS.
- Make sure B is stored in the GPS as a waypoint. Press find, and arrow down to select point B (don't push enter)
- The GPS will show distance and bearing from your current position to the selected waypoint. If you see a small "M" after the bearing, it's showing magnetic bearing...use that for your compass alignment. If you see a small "T" it's showing true. Go into global settings -> units and change it to Magnetic.
Andris Bjornson
Since graduating from Northwestern University with a Physics degree, I have helped build long-distance nonprofit WiFi networks as a volunteer in Nepal, managed communications-hardware deployments for the U.S. Department of State, created a high-volume image archive system for an A-list advertising photographer, and helped tell the story of landmine survivors through documentary multimedia. This multi-disciplinary career path has been my attempt to blend passions for technology, creativity, and global involvement. Outside of work, I am an avid photographer and I try to spend as much time as possible getting to the top of tall things by boot, bike, climbing harness, or ice axe.
Goat*Net: Bleating Edge WiFi Mesh Networking from Inveneo
The WiFi hackers at Inveneo, famous for their long-distance network in Haiti, are piloting a new Internet connectivity solution that they hope will bring Internet access to currently unreachable corners of rural Africa. Deploying collar-mounted wireless transceivers on a herd's worth of goats, they've created a mobile, self-healing, self-configuring network they've dubbed the Goat*Net.
Rural WiFi challenge
Rural Africa suffers from two distinct disadvantages that hinder the easy and affordable provision of Internet access - long distances between users and no electrical infrastructure. One possible solution to these challenges often employed by Inveneo is long-distance WiFi.
Even WiFi has its limits, though. On a recent trip to Ethiopa, Inveneo found rugged terrain and highly mobile populations would make a standard WiFi deployment difficult or impossible. Transient herdsmen rarely stop at one location for an extended period of time and often wander in and out of coverage areas of traditional networking solutions.
The challenge became how to give these herdsmen access to the same benefits of information and communication technologies (ICT) as Africa's more stationary populations.
Goat*Net: Bleating Edge Rural WiFi
While conducting a site survey of the environment and ICT needs of Afar goat herders in the Ethiopian Danakil Desert, Inveneo Project Engineer Andris Bjornson was hard pressed to come up with a traditional WiFi solution that worked:
"The rolling hills and many tall trees were making it difficult to find lines of sight that would make the network feasible"
One hot afternoon while pausing for a mishkaki snack, Andris had an intriguing thought - why not build a mobile WiFi mesh network using goats? This was the start of Goat*Net.
A mesh network is different from more traditional networks because each mesh node acts as an independent router. A mesh network continuously reconfigures or "heals" itself - finding ways around broken or blocked paths.
Inveneo paired Ubiquiti PicoStations mounted on the collars of goats with stationary Ubiquiti Airmax sector antennas to form a grazing, wandering, self-healing mobile network. As goats wander from ridgetops to valleys, the network continually adapts routing to find the best paths back to the stationary antennas and eventually to the Internet.
Goat*Net Mesh TopologyCurrently, the PicoStations are powered by long-life rechargeable batteries, but Inveneo is investigating a biogas power solution, enabling the devices to be powered by waste methane produced by the goats.
Goat*Net has had a huge impact on the lives of Afar goat herders, bringing the community into the modern world. As one was quoted as saying:
Goat*Net has brought real change to our community. We can now get CBOT spot prices for nyama choma
Inveneo is excited to push this new technology even further as part of its Goat Ahead ProgramTM to bring technology to ewe. According to Inveneo CIO Mark Summer:
"We've already been able to do so much with just 50 goats in a network, but that's just a start. We have plans to scale up to a full 1 kilogoat next year. As wireless radios shrink further and prices come down, the dream of a full megagoat network could be realized within 5 to 10 years."
Andris Bjornson
Since graduating from Northwestern University with a Physics degree, I have helped build long-distance nonprofit WiFi networks as a volunteer in Nepal, managed communications-hardware deployments for the U.S. Department of State, created a high-volume image archive system for an A-list advertising photographer, and helped tell the story of landmine survivors through documentary multimedia. This multi-disciplinary career path has been my attempt to blend passions for technology, creativity, and global involvement. Outside of work, I am an avid photographer and I try to spend as much time as possible getting to the top of tall things by boot, bike, climbing harness, or ice axe.
Is Data Security and Encryption Really Necessary in Rural Africa?
I am often asked about cyber security on WiFi networks for international development projects in rural Africa. My response is usually a laugh, as I find it hard to believe that anyone would have both the cunning and the desire to go wardriving through northern Uganda.
But then I was told about smart Nigerian hackers who were breaking encryption at Lagos HIV clinics in hopes to find out anyone important who has AIDS. This has me thinking, is data security now an issue in ICT4D?
I still maintain that for the vast majority of technology deployments, especially in schools and community centers and rural locations, basic security measures are enough.
Require user accounts for each person, use WPA2 on WiFi links of importance, and if you want to have unsecured WiFi for the community, use a separate Internet router.
Its only in high-risk settings, where the data could be a serious privacy issue that you need to worry about data security, encryption, and the like. Health and banking implementations like eHealth and microfinance, or urban settings where ICT skills and knowledge exist in enough abundance to be an issue.
Yet what do I know? What's your opinion on the cyber security needs in rural Africa? Do we really need to be concerned about black hat hackers outside of capital cities?
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Wayan Vota
InveneoWayan Vota is a technology expert focused on appropriate information and communication technologies (ICT) for rural and underserved areas of the developing world. He is a Senior Director at Inveneo and is the editor of ICTworks
Seamlessly Transfer Data Between Google Earth and Radio Mobile
It's the classic dilemma: Google Earth has the fantastic interface you need to keep track of your GPS data, and high resolution imagery that lets you find the exact spot on the planet you're looking for. Radio Mobile puts powerful tools of radio line of sight calculation at your fingertips, but its interface isn't nearly as polished as Google Earth's. Where do you put your data first?
Do both! Radio Mobile units can be imported and exported seamlessly as KML files. In Radio Mobile, look under "File -> Units Properties" and click the Export or Import buttons on the right side of the window to get started. (screenshot)
Saving Google Earth places to KMLImporting a KML file to Google Earth is as simple as choosing "File -> Open". Exporting from Google Earth is almost as easy...just right click on the waypoint or folder full of waypoints and choose "Save Place As..."
When exporting, make sure you save your points as KML files (rather than the default compressed KMZ) otherwise Radio Mobile won't know what to do with them.
Thanks to import/export, you can use Google Earth as a tool to download your waypoints directly from your GPS, organize them into folders, and then export them to Radio Mobile. This saves time and helps you avoid typing mistakes that could cause you real problems later.
After you've modeled your wireless network, take the time to export any new radio sites you've created back to Google Earth and into your GPS. This will make it easy to find your project sites and turn them from points on a map into antennas on the ground.
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Andris Bjornson
Since graduating from Northwestern University with a Physics degree, I have helped build long-distance nonprofit WiFi networks as a volunteer in Nepal, managed communications-hardware deployments for the U.S. Department of State, created a high-volume image archive system for an A-list advertising photographer, and helped tell the story of landmine survivors through documentary multimedia. This multi-disciplinary career path has been my attempt to blend passions for technology, creativity, and global involvement. Outside of work, I am an avid photographer and I try to spend as much time as possible getting to the top of tall things by boot, bike, climbing harness, or ice axe.
Create Accurate WiFi Links, Free with ASTER GDEM
In 1999, the US and Japan jointly launched the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) into orbit. One of the goals of the ASTER instrument mission was to conduct detailed terrain mapping of the surface of the earth.
The ASTER global digital elevation model (GDEM) covers the planet from 83 degrees north to 83 degrees south at 1 arcsecond resolution and is the "most detailed 3d map of the Earth ever made."
In June of 2009, the ASTER GDEM was released to the public.
For us as builders of long distance wireless networks, this is mostly of interest because it allows us to do more accurate computer modeling of radio lines of sight to answer the basic question "If I build antennas at point A and point B...can they talk to each other?"
If you want to try it out for youself, see our detailed technical guide on how to download and convert this data to a format compatible with RadioMobile, the widely used free software for modeling radio propagation.
We recommend ASTER GDEM in addition to SRTM3 (previously the highest global terrain model available) as some of our partners in Nepal have had significant difficulties with "voids" or blank spots in the SRTM3 data right in the middle of their project sites.
Using SRTM3, RadioMobile will tell you a line of sight through a void will work, when in the real world it might not. We have seen significantly fewer voids in the ASTER GDEM data. If SRTM3 has voids where you need to plan a link, try the ASTER data.
Andris Bjornson
Since graduating from Northwestern University with a Physics degree, I have helped build long-distance nonprofit WiFi networks as a volunteer in Nepal, managed communications-hardware deployments for the U.S. Department of State, created a high-volume image archive system for an A-list advertising photographer, and helped tell the story of landmine survivors through documentary multimedia. This multi-disciplinary career path has been my attempt to blend passions for technology, creativity, and global involvement. Outside of work, I am an avid photographer and I try to spend as much time as possible getting to the top of tall things by boot, bike, climbing harness, or ice axe.





I wanted to participate.. I have my businessplan ready but am not lucky the deadline has passed! damn
Hope ICT n colleges would be taking more seriously as President Jonathan runs for another eight years
kindly see if you can engage yourselfs with us on this team building event that is taking place at Eyethu hall, Khayelitsha in Cape town...
Dear Friend,
ABA Foundation is a Non-Profit Organization registered under the laws of Uganda. The Foundation's objective is to...
You can submit an application for Development Innovation Ventures funding anytime before July 21, 2011