(Riya Singh, Intern Journalist): Bharti Airtel CEO Gopal Vittal said prices of data and voice services need to be increased as current levels of the tariff are unsustainable for the industry. “We’re at a premium (in terms of tariff hike). You can have a premium but it becomes unsustainable after a point,” he said. Vital didn’t give a timeline on the tariff hike.