With T-Mobile grabbing a lot of headlines for its no-contract phones, AT&T is launching a new brand of its own focused on that segment. Aio Wireless (pronounced Ay-Oh) is launching in three cities — Houston, Orlando and Tampa. Plans range from $35 to $70 a month, and devices offered include smartphones from ZTE and Samsung, as well as the Nokia Lumia 620 (a Windows Phone model that previously hadn’t found its way stateside). Customers can also bring their own devices to the network. It also has the iPhone at standard unsubsidized prices, meaning that a 16 gigabyte iPhone 5 sells for $649. At the other end of the spectrum, the ZTE Prelude, an entry-level Android device, is priced at $49. Aio’s website has a decidedly non-corporate feel, with a woodgrain background and promises of being “simple” and “delightful” — two words not always associated with wireless carriers. AT&T is taking another page from T-Mobile’s playbook, offering unlimited data with all its plans, but pricing the different options based on how much of that data customers want at full speed.