TRAI is planning to start a consultation process to review call connect charges, also known as inter-connection usage charges (IUC), for the telecom network - a move that could bring down call rates. In February 2015, during the previous review of IUC, the regulator removed charges that a landline service provider has to pay to other players for transmitting a phone call of its customers. The benefit of the waiver was passed on to consumers by leading fixed-line providers. This prompted PSUs BSNL and MTNL to start free unlimited night calling plans. Among private operators, Bharti Airtel offers unlimited local and STD calls from its landline connection on any network throughout the day for a fixed monthly charge. TRAI also reduced network IUC on calls made from mobile phones by about 30 percent to 14 paise per call, from 20 paise earlier. Telecom subscribers cannot communicate with each other or connect to other networks unless necessary inter-connection arrangements are in place. A telecom company is required to pay inter-connection charges when its subscriber makes a call to a subscriber of another network. The charge gets added up in final price that a subscriber has to pay. Similarly, the regulator waived off fixed termination charges that are levied on calls made from a mobile phone to a landline number.