As more consumers use their smartphones and tablets over wireless networks, AT&T is introducing three new pricing levels for its data plans, and tiered them according to smartphone and tablet usage. The new smartphone plans, launching this Sunday, are: 300 megabytes of data for $20 a month; 3GB of data for $30 a month, or 5GB of data for $50 a month. (On the final two plans, smartphone users can add additional usage at $10/additional gigabyte.) Tablet users will be offered the $20 and $30 monthly plans. "Customers are using more data than ever before," said David Christopher, chief marketing officer, AT&T Mobility and Consumer Markets, in a statement."Our new plans are driven by this increasing demand in a highly competitive environment, and continue to deliver a great value to customers, especially as we continue our 4G LTE deployment." Current customers will have the choice of keeping their current plans or switching to the new tiers.