Yagi Antenna and Our Merry Band of Hackers
We are a community of Free Software activists and Hardware hackers from Puducherry, India, working together to form a community owned and maintained Mesh Network in our city. If you have no idea what I’m talking about read this article on Why Meshnet? The inception of this idea started 8 months ago, when we recognized the need for Alternate Free Infrastructure owned by the people, a network that respects people’s freedom of speech and privacy. We experimented with a number of P2P applications and tried our hand at CJDNS, a network protocol suite designed for mesh networking. We were treading on uncharted territory. Naturally we failed, crashed and burned. But the idea was still there, lingering on the back of our minds.
The real work started just around 2 months ago, at a meetup at OpenDrops. During this meetup, we focused our discussion on planning, goal setting and deadline driven development. We started our work again with a renewed purpose and a new protocol, B.A.T.M.A.N which is more mature and popular than CJDNS. In these 2 months, we solved most of our technical problems and we have formulated a strategy to reach out to the general populace. New people whose goals aligned with ours, joined us. We decided to meet every fortnight and address the issues at hand and solve them with collective intelligence.
Some of the important tasks we have accomplished are,
- Build Openwrt based custom firmware for a router to be part of the mesh
- Provide access to the network for non-mesh devices via an Access Point
- Test applications for VoIP, Chat, Social Networking and File transfer
- Draft a long term Action plan to reach our goals
There is a need to connect small clusters of mesh nodes spread across the city. A High Gain Directional Antenna that can reach a distance of 2 miles, might just do it. Since none of us had any idea how an antenna works, search for a DIY antenna took a while. Finally we found this tutorial on instructables, for building a Yagi antenna that supports 2.4GHz signal. Due to unavailability of some components and a general unfamiliarity with antennas, the actual construction was delayed.
Last week, we decided we give it a try anyway. On Sunday, 10th of April, Free Hardware hackers in our city, gathered at Pondicherry Science Forum to celebrate Hardware Freedom Day. We joined them while they were having a discussion on Beaglebone vs Raspberry Pi. Later we had a discussion on Mesh networks and the need for antennas to support the network. Fortunate for us, Swaminathan who is familiar with Antennas and Radio Communication, joined us this time. He explained to us, what makes an antenna work and assured us that this will work.
We started making the antenna elements by straightening and cutting 2mm thick copper wires. Everyone chipped in. Before long, the antenna was built and ready to go. We opened up a router, desoldered the default antenna connection, soldered our antenna to the router’s electrical output pin/slot (the RF source).
We switched on the router and it just worked. We observed a stable signal for more than 100 meters in the direction of the antenna, more than what the default omni-directional antenna could provide.
We had some difficulties, we had to redo the soldering, after the antenna disconnected from the router. It was a mess. Someone burned himself with the soldering iron. But it was fun. We resoldered it and tested the signal stability for longer distances. We tried streaming videos from the internet. It just worked. Flawlessly!
Everyone in our Mesh Net community wants something out of this initiative. Students from Villupuram, wanted to provide internet connection to the hostels in their campus. Some of us want to provide network services to the rural areas. Some of us just want to learn about networking.
Me? I just want to connect the Mesh Network initiatives all around the world, like Freifunk, WLAN Slovenija, to unite and work towards a common goal : An Affordable, Unrestricted, Private and Secure Internet for everyone.