Bharti Airtel is planning to widen its coverage in the Tamil Nadu circle to 100 per cent. The company is in the process of increasing its current SMS capacity threefold to 5,850 messages per second from 1,850 messages per second, by March 2008.

According to Bharti Airtel, of the Rs 3.5 billion investment planned for 2007-08, a substantial proportion is being invested in the state.