Cantennas deployed in Kuppam, Andhra Pradesh
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This past week the Kuppam team has successfully deployed wireless connectivity to several new sites (in this case, village police stations) using cantennas. This design is based on the approach described here and also here, using locally available metal cans.
Although the cost of external antennas has fallen substantially in the past couple of years here in the US, the Indian domestic prices for wireless equipment is still quite high, partly because much of the equipment is imported from the US and other sources, which makes the effective price there around 2x the US prices after adding in shipping and import tariffs.
This particular cantenna design was selected for use in Kuppam because it can be built by relatively untrained workers with almost no tools other than a ruler, screwdriver, metal file, and soldering iron (or hand torch), and provides reasonably good performance (8-10dB gain) without being fussy about radiator placement. (I had my 8-year-old daughter build one of the prototypes to test the instructions, although I did the actual soldering.)
The only commercially purchased components are the RF N-connector and the screws. The effective cost of the antennas is below $5.00, versus over $100.00 for a comparable commercial unit in India. This is a major reduction in the total cost of rolling out connectivity to a new site within the Kuppam wireless footprint.
This set of cantennas and associated wireless links was also built and installed entirely by the Kuppam team, which I find quite gratifying. In the course of two years they have gone from being completely dependent on outside technical help to now being comfortable surveying candidate sites and configuring the links on their own.
The RF cabling itself is also a major component of the cost. Some sites may be able to use USB wireless adapters in place of the radiator to eliminate the RF cable and separate radio, although this leaves the adapter somewhat exposed to the weather and other environmental hazards, such as birds, rodents, and monkeys.
