AAL0 cell format of an ATM protocol for communicating voice traffic in a CDMA system
View Patent ↗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.
1. A device configured to communicate voice data under an ATM protocol, the device comprising:
a communication interface configured to receive a full-rate voice data signal, wherein the full-rate voice data signal comprises one or more frames, wherein each frame includes a segment of full-rate voice data, wherein the segment of full-rate voice data included in said each frame is 24 bytes;
an ATM Adaptation Layer 0 (AAL0) cell-generation system configured to generate an AAL0 cell that corresponds to each of the one or more frames, wherein each AAL0 cell comprises:
a header field, wherein the header field is 5 bytes;
a data field comprising the segment of full-rate voice data included in the frame, wherein the data field in said each AAL0 cell is 24 bytes;
a PAD field for padding the AAL0 cell such that the size of the AAL0 cell is in accordance with the ATM protocol, wherein the PAD field is 3 bytes;
a 1-byte length field containing information for indicating a size of the segment of full-rate voice data included in the frame;
a 19-byte control-data field containing information for controlling the full-rate voice data signal; and
a 1 -byte error-detection field containing information usable to detect one or more data errors in said full-rate voice data; and
a cell-processing system configured to generate an ATM Adaptation Layer 2 (AAL2) cell corresponding to each generated AAL0 cell, wherein each AAL2 cell comprises a data field that includes the segment of full-rate voice data from the AAL0 cell from which the AAL2 cell was generated, and wherein the device is further configured to send the AAL2 cells to a base station controller (BSC) in a CDMA network;
wherein the device is a base transceiver station (BTS) in the CDMA network.
2. The device of claim 1 , wherein each frame comprises a payload that includes the segment of full-rate voice data included in the frame, the device further comprising:
a payload-extraction system configured to extract the payload from each frame and provide the payload to the AAL0 cell-generation system.
3. The device of claim 1 , wherein the device is further configured to receive one or more ATM Adaptation Layer 2 (AAL2) cells, wherein each AAL2 cell comprises a data field that includes a segment of full-rate voice data;
the device further comprising a payload-extraction system configured to extract the segment of full-rate voice data from each AAL2 cell and provide a payload from the segment to the AAL0 cell-generation system.
4. A device configured to communicate voice data under an ATM protocol, the device comprising:
a communication interface configured to receive one or more ATM Adaptation Layer 2 (AAL2) cells, wherein each AAL2 cell comprises a data field that includes a segment of full-rate voice data, wherein the segment of full-rate voice data is 24 bytes, and wherein the AAL2 cells are received from a base transceiver station (BTS) in a CDMA network that generates each AAL2 cell from a corresponding ATM Adaptation Layer 0 (AAL0) cell; and
an AAL0 cell-generation system configured to generate an AAL0 cell that corresponds to each of the one or more received AAL2 cells, wherein each AAL0 cell comprises:
a header field, wherein the header field is 5 bytes;
a data field comprising the segment of full-rate voice data included in the AAL2 cell;
a PAD field for padding the AAL0 cell such that the size of the AAL0 cell is in accordance with the ATM protocol, wherein the PAD field is 3 bytes;
a 1-byte length field containing information for indicating a size of the segment of full-rate voice data included in the AAL2 cell;
a 19-byte control-data field containing information for controlling said full-rate voice data; and
a 1-byte error-detection field containing information usable to detect one or more data errors in said full-rate voice data;
wherein the device is a base station controller (BSC) in the CDMA network.
5. The device of claim 4 wherein the data field in said each AAL0 cell is 24 bytes.
6. A method for communicating voice data under an ATM protocol, the method comprising:
receiving a full-rate voice data signal, wherein the full-rate voice data signal comprises one or more frames, wherein each frame includes a segment of full-rate voice data, wherein the segment of full-rate voice data included in said each frame is 24 bytes;
generating an ATM Adaptation Layer 0 (AAL0) cell corresponding to each of the one or more frames, wherein each AAL0 cell comprises:
a header field, wherein the header field is 5 bytes;
a data field comprising the segment of full-rate voice data included in the frame, wherein the data field in each generated AAL0 cell is 24 bytes;
a PAD field for padding the AAL0 cell such that the size of the AAL0 cell is in accordance with the ATM protocol, wherein the PAD field is 3 bytes;
a 1-byte length field indicating a size of the segment of full-rate voice data included in the frame;
a 19-byte control-data field containing information for controlling full-rate traffic data; and
a 1-byte error-detection field containing information usable to detect one or more data errors in said full-rate voice data;
generating an ATM Adaptation Layer 2 (AAL2) cell corresponding to each generated AAL0 cell, wherein each AAL2 cell comprises a data field that includes the segment of full-rate voice data from the AAL0 cell from which the AAL2 cell was generated; and
sending the AAL2 cells to a base station controller (BSC) in a CDMA network;
wherein the method is carried out at a base transceiver station (BTS) in the CDMA network.