TRAI has revised its tariff regulations, mandating mobile operators to offer separate voice and SMS plans for customers not using data.The move aims to ensure more tailored services for users and make it easier for consumers to pay for services they generally use.The regulatory authority believes that separate special tariff vouchers for voice and SMS, alongside existing data-only plans, should be mandatory.The regulator has also permitted telecom operators to offer recharge vouchers of any value, with a minimum recharge coupon worth Rs 10.