Telecom Regulatory Authority of India (Trai) today announced a substantial cut in access deficit charge (ADC), and shifted to a revenue share regime from per call basis.According to an official statement issued today, Trai has fixed ADC at 1.5% of the adjusted gross revenue (AGR) for private operators - a move that would bring down telecom tariffs drastically.As per Trai estimates, ADC from 1.5% of AGR would stand at Rs 1,278 crore, incoming ISD calls would fetch Rs 1,800 crore and outgoing ISD calls would garner Rs 257 crore. The total quantum of ADC would thus come to Rs 3,375 crore.Of the total quantum, Rs 3,200 crore would go to BSNL, which is 33% lower that the existing over Rs 5,000 crore, Trai said.Trai has reiterated that ADC would come down to zero by 2008-09.