The Telecom Disputes Settlement Appellate Tribunal (TDSAT) has directed Mahanagar Telephone Nigam Limited (MTNL) to reduce the infrastructure charges it collects from private operators. TDSAT also asserted that the charges should not be increased by over 10 per cent per annum. It has asked the Telecom Regulatory Authority of India (TRAI) to frame the guidelines for fixing such charges. Private telecom operators pay infrastructure charges to MTNL and BSNL as rental and maintenance fee for stationing their link equipment including terminals and antennas on the PSUs' premises. This enables private operators to connect to the PSUs' national long distance (NLD) and international long distance (ILD) networks.