The Telecom Disputes Settlement and Appellate Tribunal (TDSAT) has ruled in favour of operators on one-time spectrum charges (OTSC), but the Department of Telecommunications (DoT) has challenged the body’s decision in the Supreme Court, the Economic Times reports. The OTSC was an additional levy introduced in 2013 in the wake of the 2G scandal, and applied a market-determined price for spectrum awarded administratively in excess of 4.4MHz. Under an earlier licensing regime, providers were allotted start-up spectrum and then granted additional airwaves once their user base passed certain milestones. In its ruling, the TDSAT said that the government could not apply the OTSC retrospectively – i.e. from January 2013 onwards – and could only apply the charge to spectrum beyond 6.2MHz.