Disclosed herein are devices and methods for communicating full-rate voice data under an ATM protocol. An exemplary device is configured to communicate voice data through a vocoder in a CDMA backbone network using an ATM Adaptation Layer 0 (AAL0) cell-generating system, which is configured to generate an AAL0 cell for each frame of full-rate voice data. In an exemplary embodiment, the device generates AAL0 cells that each comprise (a) 5 bytes of a Header field; (b) 1 byte of a Length field indicating a size of the voice data; (c) 24 bytes of a Voice-Data field containing the voice data; (d) 19 bytes of a Control-Data field containing information for controlling the voice data; (e) 1 byte of an Error-Detection field containing information for detecting an error of the voice data; and (f) 3 bytes of a PAD field for padding data used to exactly fit into the ATM cell.