Bharti Airtel has begun switching off its 3G network to refarm the spectrum for 4G services, the Economic Times writes. The first stage of the phase-out has taken place in Kolkata, where the telco has deactivated its 3G platform and plans to use the 900MHz frequencies to strengthen indoor coverage of its 4G network in the circle. CTO Randeep Sekhon was quoted as saying of the development: ‘This is in line with our stated strategy of focusing on serving quality customers with best-in-class service experience. Going forward, we plan to refarm all of our 3G spectrum across India and deploy it for 4G in a phased manner. Also, it complements the smartphone ecosystem, which has now gravitated overwhelmingly towards 4G only devices.’ The cellco said it intends to continue operating its 2G network to serve the needs of customers on feature phones, however.