Mahanagar Telephone Nigam Limited is engaged in providing of fixed-line and other basic telecommunications services in Delhi and Mumbai. During the fiscal year ended March 31, 2009 (fiscal 2009), its fixed-line telecommunications networks in Delhi and Mumbai had an aggregate of approximately 3.69 million fixed lines in service. The Company has launched its cellular services using global system for mobile communications (GSM), technology in Delhi and Mumbai and had approximately 4.18 million subscribers as of March 31, 2009. GSM is the European and Asian standard for digital mobile telephone networks. In fiscal 2009, its network had approximately 3.59 million access lines in service in Delhi and approximately 4.47 million access lines in service in Mumbai. In fiscal 2009, approximately 22% of its revenue was derived from call charges, 62% from rentals of telephones, access lines and other telecommunications equipment and use of its value-added services and 5% from public call offices.