Nevertheless , Apple is in talks with both AT & T and Verizon to support the tablet , according to sources within the companies : One version of the device will run on CDMA networks such as Verizon 's , and one will operate on GSM networks like that owned by AT & T. The AT & T part isn 't surprising , given early reports that the tablet would rely on HSDPA , a feature used by AT & T that , according to company spokesman Mark Siegal , " effectively doubles the speed of our 3G network . "