# US 2013/0156416 A1 · Packet-optical combined switching system and protection switching method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0156416 A1 - Document ID: US20130156416A1 - Status: Published application - Kind: A1 - Application number: 13/658,361 - Filed: 2012-10-23 - Published: 2013-06-20 - Earliest claimed: 2011-12-19 - Assignees: Electronics and Telecommunications Research Institute - Inventors: Ki Won KIM; Ho Young SONG; You Hyeon JEONG - Web page: https://patentgrep.com/patent/US20130156416A1 ## CPC - H04B 10/032: using working and protection systems {(H04J14/0287 takes precedence)} - H04J 14/0268: {Restoration of optical paths, e.g. p-cycles} - H04Q 2011/0081: {Fault tolerance; Redundancy; Recovery; Reconfigurability} - H04B: TRANSMISSION - H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S) - H04Q: SELECTING (switches, relays, selectors H01H; wireless communication networks H04W) ## Abstract A protection switching method of packet-optical combined switching system in accordance with the inventive concept may include detecting whether or not an obstacle occurs in a packet path; performing a first protection switching using a preliminary path if an obstacle is detected from the packet path; generating an imaginary preliminary path using a preliminary resource of optical path when the first protection switching is failed; and performing a second protection switching using the imaginary preliminary path. ## Claims ### Claim 1 A protection switching method of packet-optical combined switching system comprising: detecting whether or not an obstacle occurs in a packet path; performing a first protection switching using a preliminary path if an obstacle is detected from the packet path; generating an imaginary preliminary path using a preliminary resource of optical path when the first protection switching is failed; and performing a second protection switching using the imaginary preliminary path. ### Claim 2 (depends on 1) The protection switching method of claim 1, wherein performing the first protection switching further comprises generating a new preliminary path using a resource of the packet path when there is not the preliminary path. ### Claim 3 (depends on 1) The protection switching method of claim 1, wherein generating the imaginary preliminary path further comprises mapping a path signal of packet hierarchy and a path signal of optical hierarchy. ### Claim 4 (depends on 3) The protection switching method of claim 3, wherein generating the imaginary preliminary path comprises: searching a resource of optical hierarchy; and generating the imaginary preliminary path using the searched resource. ### Claim 5 (depends on 4) The protection switching method of claim 4, further comprising notifying a failure of the second protection switching to an operation system if there is not a resource of optical hierarchy that can be used in a step of searching a resource of the optical hierarchy. ### Claim 6 (depends on 1) The protection switching method of claim 1, wherein the packet path is a high rank path and the optical path is a low rank path. ### Claim 7 A packet-optical combined switching system comprising: a plurality of packet-optical combined switches; and a protection restoration control device controlling a protection switching for packet path or optical path of each of the plurality of packet-optical combined switches, wherein the protection restoration control device generates an imaginary preliminary path using a preliminary resource of the optical path when an obstacle occurs in the packet path and performs a protection switching for the packet path using the generated the preliminary path. ### Claim 8 (depends on 7) The packet-optical combined switching system of claim 7, wherein each of the packet-optical combined switches comprises: a packet transport layer switching device performing a packet path transmission service of packet signal connected to an input/output part of packet hierarchy or a switching of packet transport layer; an optical transport layer switching device performing an optical path transmission service of optical signal connected to an input/output part of optical hierarchy; and a signal matching device mapping the packet signal and the optical signal. ### Claim 9 (depends on 8) The packet-optical combined switching system of claim 8, wherein the optical transport layer switching device periodically analyzes the optical signal to detect whether an obstacle occurs in the optical path. ### Claim 10 (depends on 8) The packet-optical combined switching system of claim 8, wherein the packet transport layer switching device periodically analyzes the packet signal to detect whether an obstacle occurs in the packet path. ### Claim 11 (depends on 10) The packet-optical combined switching system of claim 10, wherein the protection restoration control device controls the packet transport layer switching device to perform a protection switching for the packet path using a preliminary path when an obstacle occurs in the packet path. ### Claim 12 (depends on 11) The packet-optical combined switching system of claim 11, wherein the protection restoration control device controls the packet transport layer switching device to generate a new preliminary path using a resource of the packet hierarchy when there is not the preliminary path and perform a protection switching for the packet path using the new preliminary path. ### Claim 13 (depends on 12) The packet-optical combined switching system of claim 12, wherein the protection restoration control device controls the signal matching device to mapping the packet signal to the optical signal or inversely mapping the optical signal to the packet signal when there is not the preliminary path and a preliminary path cannot be generated from the packet hierarchy, wherein the protection restoration control device controls the optical transport layer switching device to generate the imaginary preliminary path using a resource of the optical path, and wherein the protection restoration control device controls the packet transport layer switching device to perform a protection switching for the packet path using the imaginary preliminary path.