New Delhi, Jan. 2: Mahanagar Telephone Nigam Ltd (MTNL), the telecom service provider in Delhi and Mumbai, has launched three new basic plans for its Integrated Subscriber Digital Network (ISDN) customers — general, special and super.

ISDN is a state-of-the-art public switched digital network offering different services — voice, data and image transmission — over the network.

MTNL has launched the ‘General’ plan with a monthly rental of Rs 500 and calls at Rs 1.10 per unit with a 90-second pulse rate. There will be no free calls.

Under the ‘Special’ plan, the company will charge a monthly rental of Rs 1,500 with 1,200 free calls. A ‘Super’ scheme will be offered at a monthly rental of Rs 3,300 with 3,600 free calls. The unit call charges will be the same at Rs 1.10 per unit under special' plan as in case of General Plan and Rs 1 for 'Super' plan.