PROTECTION SWITCHING METHOD IN ATM TRANSFER SYSTEM WITH RING STRUCTURE

摘要

PURPOSE: A protection switching method in an ATM transfer system with a ring structure is provided to simplify a construction and reduce a switching delay time by performing a software process and a hardware process together for an APS(Auto Protection Switching) cell generation, detecting, insertion and protection. CONSTITUTION: When a controller is informed an error of a first optical fiber by a first FPGA(Field Programmable Gate Array)(S601), it checks whether a switching is possible to a fourth optical fiber and performs a protection switching so that every ATM can be received through the fourth optical fiber(S602). If the controller is informed an error of the fourth optical fiber by a second FPGA(S603), it checks whether a switching is possible to the first optical fiber and performs a protection switching so that every ATM cell can be received through the first optical fiber(S604). When the controller receives an APS cell through the first optical fiber from the first FPGA, it analyzes the APS cell, checks whether a switching is possible to the fourth optical fiber, and then, does not perform a protection switching on an ATM cell received from a device of which identification information is inserted in the received APS cell, and meanwhile, performs a protection switching on an ATM cell received from a device of which identification information is not inserted in the received APS cell so that the ATM cell can be received through the fourth optical fiber(S606). When the controller receives an APS cell through the second optical fiber from the second FPGA, it analyzes the APS cell, checks whether a switching is possible to the first optical fiber, and then, does not perform a protection switching on an ATM cell received from a device of which identification information is inserted in the received APS cell, and meanwhile, performs a protection switching on an ATM cell received from a device of which identification information is not inserted in the received APS cell so that the ATM cell can be received through the first optical fiber(S608).