Indian cellcos owe the government a total of INR926.4 billion (USD13.5 billion) in pending fees due to a long-standing dispute over the calculation of adjusted gross revenue (AGR), upon which licence fees and spectrum usage charges are based, the Department of Telecommunications (DoT) has told the Supreme Court, the Economic Times writes. The legal battle dates back to 2003, with the DoT arguing that all sources of income should be included in the AGR calculations, whereas the providers claim the amount should limited to telecom services. According to the ministry, Vodafone Idea and Bharti Airtel have the largest outstanding bills, of INR283.1 billion and INR216.8 billion, respectively, followed by Reliance Communications (RCOM, INR164.6 billion), Tata Teleservices Limited (TTSL, INR99.9 billion) and Aircel (INR78.5 billion).