System and method for realizing electrical layer linear protection in POTN

The invention relates to a system and method for realizing electrical layer linear protection in POTN, relating to the POTN field. A business mapping unit of a source end converts ODUk channel data into a group of cells through cell segmentation, a multicast ID is distributed, the cells are subjected to concurrence or selection at work and protection light channel units through a cell switching unit, and after the cells are received by the work and protection light channel units, the cells are selectively activated and are sent to the corresponding cell reception ports; after the work and protection light channel units of a destination end receive signals, the de-mapping and de-multiplexing of ODUk is completed, the cells are sent out via the corresponding channels, a system cross is established to point to the business mapping unit; and the signal failure, signal deterioration, and APS overhead information are detected, an APS control unit notifies the current needed light channel units to activate the cross and non-needed light channel units to block the cross. The ODUk electrical layer linear protection is realized under the unified cell exchange configuration of POTN, and the high effectiveness and the reliability are guaranteed.