Even in today’s high-tech world of unified communications and wireless mobility, the idea of two kids with laptops sitting under a tree somewhere in Saharan Africa being able to exchange information without any kind of infrastructure or configuration, seems as wild an idea as the land they live in.
But with the OLPC project, this scenario is rapidly becoming a widespread reality.
James Cameron works for a computer company in support for enterprise Linux customers, and is deeply immersed in electronics, radio and software engineering. For the past two years Cameron has devoted his diverse technical talents to testing the wireless network component of the One Laptop Per Child project.
Cameron got involved with the project because he lives and works in the outback, in a small village called Tooraweenah, 58km from Coonabarabran (approx 500km northwest of Sydney).
There are few wireless access points and little noise in the radio spectrum there, making it the perfect location for testing the OLPC XO laptops as it mirrors the third world environments they are being deployed in.
“One of our test scenarios is two kids under a tree, in the middle of nowhere, who want to transfer a file between one laptop and another. At the moment with the software that we have, the hardware, and the mesh automation, they can open their laptops, transfer whatever it is they want and then walk off. They don’t need any IP address configuration or anything special. It just works,” he said.
Mesh networking increases the range of an access point. It is a type of wireless networking that uses redundant and distributed nodes to increase the reliability and range of the network. It is used to route information between OLPC XOs by turning the laptop and the child carrying it into the network infrastructure.
“Instead of the client PCs going to a single central point, what happens with a mesh network is they find their way to a selected point by working through all the other nodes in the mesh,” Cameron said.
The mesh network is self-healing and autonomous, and meets the goals of the OLPC project by working without the need to hire electricians and radio specialists to make it work.
“The kids don’t have to live within sight of the school to be able to use the school’s repository of information, like its online library; they only have to be within radio sight of another kid who is within radio sight.
“They [schools] don’t need to put in the infrastructure to cover the whole village – the kids carry it with them as they go home. It means you can deploy to more schools because you don’t have to pay for the extra infrastructure,” Cameron said.
Testing in the outback, Cameron discovered that the range of the XO could go up to 1.6km “quite easily” at 1.5m above ground.
But in the vast Australian outback, the Sahara or any other great rural expanse, 1.6km is still a very short distance.
“Imagine the kids are down at the waterhole after school, they will take their laptops there of course because they are on their way home, but they cant get to the school server without sending some of the kids back along the path to act as mesh nodes to get there. But if we’ve got a tall tree nearby, the school can organize to put a mesh node on top of that powered by a solar panel.”
Cameron estimates a cost of about $35 for a mesh node, a battery and a solar panel that can turn any tall tree, windmill, roof or rocky outcrop into a stand alone mesh node, ensuring coverage for the kids at an affordable cost.
“Assuming a range of 1.6km holds true, (the mathematical formula for area of a circle) Pi R squared tells us one well placed mesh node will cover up to eight square kilometers.”
Cheap, conservable energy is also a big issue for the OLPC project, as many of the children who will use them wont have a way to charge their laptop at home, and will rely on their school to charge it for them.
“The school might have a generator or a solar panel, or in one school where we’ve got laptops deployed now we have two cows who walk around pushing a lever which rotates a generator that powers fifteen laptops for charging, so you get energy from wherever it’s available,” Cameron said.
The OLPC can also be powered by a hand crank, and can maintain an active wireless connection when it is hibernating.
Cameron isn’t paid for his research and development work, but gets his rewards from being able to “play with some cool gear,” and by knowing that his efforts are aiding an education revolution.
“I want to make a difference. I can’t make a difference by creating some new fantastic computer for a company because all they will do is sell it. But on this we can change the way kids learn, we can improve education over the entire planet.”
