The Mesh Potato
We spent some time setting up mesh networks and testing the limits of the system by listening to voice quality. Using the B.A.T.M.A.N. debug modes, we could see the mesh hops go around corners and through windows to relay calls from one node to another.
We still have a lot to learn about everything that affects call quality. There are many factors, such as Wi-Fi propagation, antennas, speech coding, jitter buffers, interference and system load. We are planning a small R&D project to study and optimise call quality in marginal conditions.
We need effective ways to instruct people on how to set up a reliable mesh network (like a picture book or videos or real-time metrics of quality such as a GUI or dialtone).
Wandering around in the South African winter sunshine with a Mesh Potato and a battery, I had an “ah-ha” moment that frankly sent shivers down my spine. This thing really works! You sometimes lose track of the big picture when you are engineering all the details.
Our big goal now is to simplify the installation and configuration as much as possible. At the workshop, we spent some time trying to get a Mesh Potato connected to an Asterisk server, and it was the usual time-consuming Asterisk conf file and command-line frustration. It's hard the first time, but gets easier as you gain experience. However, we want to make Village Telco setup easy for thousands of first-time users. This experience drove the point home: we need to make configuration as straightforward as possible.
It has been a pleasure to work with the Shuttleworth Foundation, Elektra and Atcom on this project. We also have had amazing input from the participants in the two Village Telco Workshops and members of the Village Telco Google Group. And, we still have a lot to do. By early 2010, we plan to resolve the remaining calibration issues, perform Beta trials and obtain type approval for the Mesh Potato. At the higher levels of the Village Telco Project, we need to integrate a billing system and the Afrimesh GUI, and integrate into a simple one-click installation.
I am confident we will achieve this and more. We have shown that a small, talented team can develop custom Wi-Fi hardware specifically for their needs. Community-based product development for community-based telephony—how cool is that!
Village Telco: villagetelco.org
Mobile Phones and Walled Gardens: manypossibilities.net/2009/01/why-wifi-in-africa
Oslec Echo Canceller: rowetel.com/ucasterisk/oslec.html
IP04 Open Hardware IP-PBX: rowetel.com/ucasterisk
Afrimesh Mesh Network GUI: code.google.com/p/afrimesh
Village Telco Google Group: groups.google.com/group/village-telco-dev
David Rowe has 20 years' experience in the development of DSP-based telephony and sat-com hardware/software. In 2005, David founded the Free Telephony Project (www.rowetel.com/ucasterisk), which has pioneered the field of open hardware embedded VoIP products. His open-source contributions include the first open telephony hardware drivers in 1999 and the Oslec echo canceller (www.rowetel.com/ucasterisk/oslec.html). David's other interests include building and advocating electric vehicles and VoIP technology for the developing world.
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