As I write I am sitting in the AirJaldi office in upper Dharamsala, Northern India. I am here to attend Extreme Com 2010. This is communications conference with a twist – early tomorrow morning we head up into the Himalayas for a 4 day trek, peaking at a height of 4400m! I am not sure how I will go, as I have never been that high before. The highest point in Australia is only around 2,200m. So I thought I better write this post. Just in case….
I arrived in Dharamsala a little early to catch up with Yahel Ben David, a good friend who I met when I first visited Dharamsala in 2006. Yahel lived in Dharamsala for 11 years and was key to setting up AirJaldi, a Wifi network that delivers Internet to thousands of people in rural India. I understand that AirJaldi has around 500 radios in their Dharamsala network, serving around 2000-3000 end user computers. I am using it now and it works really well, a lot faster than I expected.
We have already had a vigorous debate over mesh versus point-multi-point Wifi networks and I have been showing off the Mesh Potato. I have really enjoyed the discussion and look forward to learning more about Wifi for developing countries while I am here.
We have also been brainstorming some ideas for battery backed power supplies for rural Wifi. Many rural locations in developing countries have mains power. However it may drop out for days, and have nasty high voltage spikes such as 1000V for < 1ms induced from electrical storms. They also experience wide variations e.g. 60-400Vrms rather than the nominal 220Vrms. Wifi stations (especially relay stations) require battery backed power supplies that incorporate a charger and a “low voltage disconnect” that disconnects the battery when it’s terminal voltage gets too low. There are no suitable products on the market. So power supplies for rural Wifi are a surprisingly big problem that needs solving. If anyone is interested in working on a power supply for rural Wifi please contact me or Yahel. It is a very worthwhile project that could help a lot of people. More when I get back down from the mountain in 4 days!