Bharti Airtel Limited, also known as Airtel, is an Indian global telecommunications services company based in Delhi, India. It operates in 18 countries across South Asia and Africa, and also in the Channel Islands. Airtel provides GSM, 3G, 4G LTE, 4G+ mobile services, fixed line broadband and voice services depending upon the country of operation. Airtel had also rolled out its VoLTE technology across all Indian telecom circles. It is the third largest mobile network operator in India and the second largest mobile network operator in the world with over 411. 42 million subscribers. Airtel was named India's 2nd most valuable brand in the first ever Brandz ranking by Millward Brown and WPP plc.