Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
DETAILED OFFICE ACTION
Priority
Acknowledgment is made of applicant's claim for foreign priority based on an application filed in EP on 2021/11/03. It is noted, however, that applicant has not filed a certified copy of the EP21206268.1 application as required by 37 CFR 1.55.
Should applicant desire to obtain the benefit of foreign priority under 35 U.S.C. 119(a)-(d) prior to declaration of an interference, a certified English translation of the foreign application must be submitted in reply to this action. 37 CFR 41.154(b) and 41.202(e). Failure to provide a certified translation may result in no benefit being accorded for the non-English application.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 2024-07-16 in compliance with the provisions of 37 CFR 1.97 has been considered by the examiner and made of record in the application file.
Claim Status
Claims 1-11 and 16 are pending in this application and are under examination in this Office Action. Claims 12,13,14 and 15 are canceled. No claims have been allowed.
Claim Rejections - 35 USC § 112(b)
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION. —The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 4, 5, 6 and 11 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention.
Regarding claim 4,
Claim 4 depends from claim 1, yet recites “the processing and/or control element” and “the optical switching element” without providing antecedent basis in claim 1. Claim 1 does not introduce a processing and/or control element or an optical switching element (claim 1 recites a probe optical branch and output ports only). Although claim 3 introduces those elements, claim 4 does not depend from claim 3; therefore, it is unclear what structures are referenced by “the processing and/or control element” and “the optical switching element” in claim 4, rendering the scope of claim 4 unclear.
Regarding claims 5 and 6,
Claims 5 and 6 depend from claim 4 and incorporate the same antecedent-basis defect via dependency.
Accordingly, claims 4-6 are indefinite under 35 U.S.C. 112(b).
Regarding claim 11,
Claim 11 depends from claim 9, yet recites “the processing and/or control element” and “the optical switching element” without providing antecedent basis in claim 9. Claim 9 does not introduce a processing and/or control element or an optical switching element. Although claim 10 introduces those elements, claim 11 does not depend from claim 10; therefore, it is unclear what structures are referenced by “the processing and/or control element” and “the optical switching element” in claim 11, rendering the scope of claim 11 unclear.
Accordingly, claim 11 is indefinite under 35 U.S.C. 112(b).
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless -
(a)(1) The claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1, 3, 5, 7, 8, 9, and 10 are rejected under 35 U.S.C. §102 as being anticipated by Mehrvar et al. (WO2017181855A1).
Claim 1
Mehrvar teaches enabling segment routing in optical networks made up of photonic switch nodes connected by optical links, where an optical signal traverses the optical network from a source node to a destination node over one or more hops “[0013] Aspects of the disclosure relate to enabling segment routing in networks made up of photonic switch nodes. A network of photonic switch nodes is considered to be a collection of nodes capable of switching optical signals, nodes within the collection of nodes connected to each other by optical links. Each optical link between adjacent nodes may be considered a single hop. The optical signal traverses the optical network from a source node to a destination node. The source node and destination node could be adjacent nodes such that the optical signal makes a single hop from source node to destination node, or they could be separated by one or more other nodes such that the optical signal traverses two or more hops” [Mehrvar, ¶ [0013]].
Mehrvar further teaches that the source node generates a list of nodes and/or optical links that form a route from source to destination, and that each node decodes control information identifying the next hop and controls a switch in the node to route the optical signal (including payload and some or all control information) onto the next optical link “[0014] In some embodiments of the disclosure, the source node, having some predetermined knowledge of the network topology, such as a number of nodes in the network and a connectivity of the nodes in the network, generates a list of nodes and/or optical links between nodes that form a route in the network from the source node to the destination node. The nodes in the network do not necessarily need to know the entire route from source node to destination node. Each node simply decodes the control information identifying the next hop in the route towards the destination node. By utilizing the decoded control information identifying the next hop, a switch in the node can be controlled to route the optical signal including the payload and some or all of the control information onto the next optical link toward the destination node. In another embodiment, a network controller has knowledge of the network topology and provides a source routed list to the source node. The use of a controller to create the segment routing list allows for a centralization of the knowledge of the network topology and allows a plurality of nodes to act as source nodes without needing to provide each of them with the network topology” [Mehrvar, ¶ [0014]].
Mehrvar further teaches that the list forms at least part of the control information transmitted by the source node in an optical signal together with payload “[0016] The list of nodes of the intended route from source to destination forms at least part of the control information that is transmitted by the source node in an optical signal together with payload. Each node in the path receives both the payload and control information. In accordance with the received control information, a node will identify the next hop and forward the payload accordingly. Each node in the route can read the relevant control information, in a manner non-destructive to the control information associated with other nodes in the segment routed path. The expression "in a manner non-destructive to the control information associated with other nodes" is used to convey that the content of the control information associated with other nodes is not fundamentally altered. The present node is able to extract relevant control information and pass the remaining control information to the subsequent nodes. The phrase "relevant control information" should be understood to refer to control information needed by the receiving node. If a segment route defining the link that the signal should be forwarded on at each hop is encoded in the control information, each node will find the link that it should forward the signal on to be relevant, while the routing information intended for other nodes will not be relevant. While in some embodiments described in detail below the control information associated with subsequent nodes is temporarily isolated from the payload as it traverses the switch node or is converted from the optical domain to the electrical domain and then back to the optical domain by the switch node currently receiving the optical signal, the content of the control information associated with the subsequent nodes is not altered” [Mehrvar, ¶ [0016]].
Mehrvar expressly discloses an optical switch node including a wavelength diverting element and a controller configured to read control information from a diverted portion of the received optical signal, and to control an optical switch fabric to direct, to an output port selected in accordance with information carried in the diverted portion of the received signal, the optical signal carrying the payload and control information associated with subsequent nodes in a segment routed path “[0060] The optical switch node 800 includes a controller 830 optically coupled to the wavelength diverting element 840. The controller 830 is configured to read control information associated with the optical switch node 800 from an optical signal diverted from the wavelength diverting element 840 in a manner that is nondestructive to the control information associated with other nodes in the segment routed path. The controller 830 then controls the optical switch fabric 820 to direct, to an output port selected in accordance with information carried in the diverted portion of the received signal, the optical signal carrying the payload and the control information associated with subsequent nodes in a segment routed path” [Mehrvar, ¶ [0060]].
Mehrvar further teaches that the optical switch fabric routes the optical signal (including payload and control information) to one of a plurality of transmitting ports, thereby expressly disclosing selection among multiple output/transmitting ports “[0070] In some embodiments, the source optical switch node further includes the features described above that are found in the intermediate nodes. For example, the optical switch node includes at least one input ports, in which each port is configured to receive from a prior node over a respective optical link in the optical network, an optical signal carrying a payload and control information for all subsequent nodes in a segment routed path. The optical switch node includes a wavelength diverting element optically coupled to the plurality of input ports. The optical switch node may also include an optical switch fabric optically coupled to the plurality of input ports for routing an optical signal including the received payload and control information associated with at least the subsequent optical switch nodes, to one of a plurality of transmitting ports. The controller of the node may also be further configured to read control information in the received optical signal associated with the optical switch node, in a manner non-destructive to the control information associated with other nodes in the segment routed path. The controller of the node may also be further configured to control an optical switch fabric to direct, to an output port selected in accordance with information carried in the diverted portion of the received signal, the optical signal carrying the payload and the control information associated with subsequent nodes in a segment routed path” [Mehrvar, ¶ [0070]].
Accordingly, claim 1 is anticipated by Mehrvar.
Claim 3
Mehrvar teaches the segment destination node includes an optical switching element (optical switch fabric) and a processing/control element (controller) which controls the optical switch fabric to direct the optical signal to an output port selected in accordance with information carried in the diverted portion of the received signal “[0060] The optical switch node 800 includes a controller 830 optically coupled to the wavelength diverting element 840. The controller 830 is configured to read control information associated with the optical switch node 800 from an optical signal diverted from the wavelength diverting element 840 in a manner that is nondestructive to the control information associated with other nodes in the segment routed path. The controller 830 then controls the optical switch fabric 820 to direct, to an output port selected in accordance with information carried in the diverted portion of the received signal, the optical signal carrying the payload and the control information associated with subsequent nodes in a segment routed path” [Mehrvar, ¶ [0060]].
Mehrvar further teaches that the optical switch fabric routes the optical signal (including payload and control information) to one of a plurality of transmitting ports, thereby expressly disclosing selection among multiple output/transmitting ports “[0070] In some embodiments, the source optical switch node further includes the features described above that are found in the intermediate nodes. For example, the optical switch node includes at least one input ports, in which each port is configured to receive from a prior node over a respective optical link in the optical network, an optical signal carrying a payload and control information for all subsequent nodes in a segment routed path. The optical switch node includes a wavelength diverting element optically coupled to the plurality of input ports. The optical switch node may also include an optical switch fabric optically coupled to the plurality of input ports for routing an optical signal including the received payload and control information associated with at least the subsequent optical switch nodes, to one of a plurality of transmitting ports. The controller of the node may also be further configured to read control information in the received optical signal associated with the optical switch node, in a manner non-destructive to the control information associated with other nodes in the segment routed path. The controller of the node may also be further configured to control an optical switch fabric to direct, to an output port selected in accordance with information carried in the diverted portion of the received signal, the optical signal carrying the payload and the control information associated with subsequent nodes in a segment routed path” [Mehrvar, ¶ [0070]].
Accordingly, claim 3 is anticipated by Mehrvar.
Claim 5
Mehrvar teaches forwarding control information for subsequent nodes by combining wavelength channels carrying control information not associated with the present optical switch node with the payload prior to forwarding the optical signal to subsequent optical switch nodes “5. The method of claim 4 further comprising: combining wavelength channels carrying control information not associated with the optical switch node with the payload prior to forwarding to the subsequent optical switch nodes the optical signal carrying the received payload and the control information associated with the subsequent optical switch nodes in the segment routed path” [Mehrvar, claim 5].
Mehrvar further teaches converting at least a portion of the electrical signal including control information not associated with the optical switch node back into an optical signal and, before switching occurs, recombining that optical control signal with a through signal remaining from the received optical signal after dropping a wavelength channel associated with the optical switch node “11. The method of claim 10 further comprising: converting at least a portion of the electrical signal including control information not associated with the optical switch node back into an optical signal on a wavelength channel dedicated for control information for all optical switch nodes in the segment routed optical network; and before switching occurs, recombining the optical signal on the dedicated wavelength channel for all optical switch nodes with a through signal remaining from the received optical signal after dropping the at least one wavelength channel associated with the optical switch node” [Mehrvar, claim 11].
Mehrvar also teaches that the controller may convert read control information into an electrical signal for controlling the optical switch fabric, and may convert at least a portion of the electrical signal back into an optical signal on a same wavelength channel as the extracted wavelength channel, thereby forwarding control information for subsequent nodes together with the payload “[0061] In some embodiments, the controller is configured to convert the read control information associated with the optical switch node from the extracted wavelength channel into an electrical signal for controlling the optical switch fabric in the optical switch node. In some embodiments, the controller is configured to convert at least a portion of the electrical signal back into an optical signal on a same wavelength channel as the extracted wavelength channel” [Mehrvar, ¶ [0061]].
Accordingly, claim 5 is anticipated by Mehrvar.
Claim 7
Mehrvar teaches that the optical signal may traverse two or more hops between a source node and a destination node, and that each optical link between adjacent nodes may be considered a single hop “[0013] Aspects of the disclosure relate to enabling segment routing in networks made up of photonic switch nodes. A network of photonic switch nodes is considered to be a collection of nodes capable of switching optical signals, nodes within the collection of nodes connected to each other by optical links. Each optical link between adjacent nodes may be considered a single hop. The optical signal traverses the optical network from a source node to a destination node. The source node and destination node could be adjacent nodes such that the optical signal makes a single hop from source node to destination node, or they could be separated by one or more other nodes such that the optical signal traverses two or more hops” [Mehrvar, ¶ [0013]].
Mehrvar further teaches segment routing using control information carried with payload to route the optical signal hop-by-hop through intermediate nodes toward the destination
“[0014] In some embodiments of the disclosure, the source node, having some predetermined knowledge of the network topology, such as a number of nodes in the network and a connectivity of the nodes in the network, generates a list of nodes and/or optical links between nodes that form a route in the network from the source node to the destination node. The nodes in the network do not necessarily need to know the entire route from source node to destination node. Each node simply decodes the control information identifying the next hop in the route towards the destination node. By utilizing the decoded control information identifying the next hop, a switch in the node can be controlled to route the optical signal including the payload and some or all of the control information onto the next optical link toward the destination node. In another embodiment, a network controller has knowledge of the network topology and provides a source routed list to the source node. The use of a controller to create the segment routing list allows for a centralization of the knowledge of the network topology and allows a plurality of nodes to act as source nodes without needing to provide each of them with the network topology. [0015] In some aspects the optical signal may be considered to be a series of photonic frames, or bursts, in which each frame carries all of the routing information needed to route the frame from source node to destination node. Each frame being transmitted from the source node to the destination node includes control information and payload. A portion of the frame containing the control information may be transmitted on a same wavelength channel for all optical links in the network. Alternatively, the control information may be transmitted on multiple dedicated wavelength channels, wherein each dedicated wavelength channel is for a particular optical link of the network. [0016] The list of nodes of the intended route from source to destination forms at least part of the control information that is transmitted by the source node in an optical signal together with payload. Each node in the path receives both the payload and control information. In accordance with the received control information, a node will identify the next hop and forward the payload accordingly. Each node in the route can read the relevant control information, in a manner non-destructive to the control information associated with other nodes in the segment routed path. The expression "in a manner non-destructive to the control information associated with other nodes" is used to convey that the content of the control information associated with other nodes is not fundamentally altered. The present node is able to extract relevant control information and pass the remaining control information to the subsequent nodes. The phrase "relevant control information" should be understood to refer to control information needed by the receiving node. If a segment route defining the link that the signal should be forwarded on at each hop is encoded in the control information, each node will find the link that it should forward the signal on to be relevant, while the routing information intended for other nodes will not be relevant. While in some embodiments described in detail below the control information associated with subsequent nodes is temporarily isolated from the payload as it traverses the switch node or is converted from the optical domain to the electrical domain and then back to the optical domain by the switch node currently receiving the optical signal, the content of the control information associated with the subsequent nodes is not altered” [Mehrvar, ¶ [0014]-¶ [0016]].
Accordingly, claim 7 is anticipated by Mehrvar.
Claim 8
Mehrvar teaches that a packet traversing a segment routed network typically includes a header containing complete routing information, and that routing information includes a list of nodes and/or links (or a list of ports) that the packet is routed over; and that a node receiving the packet can determine where to forward by inspecting the routing information and removing an entry from the list before forwarding “[0003] Segment routing, also known as source based routing, has been used in electronic routers in communication networks. Segment routing is at least in part enabled by the at least one node in an optical network knowing the topology of the network including how each node is connected to another. A packet traversing a segment routed network typically includes a header and a payload. The header of a segment routed packet will typically include complete routing information. The routing information typically includes is a list of nodes and/or links that the packet is routed over to traverse the network. When a node in the segment routed network receives a packet, it can determine where to forward the packet by inspecting the routing information stored in the header. Before forwarding the packet, the node will typically remove an address from the source routing list. In another implementation, in place of a list of node addresses, the source routing list includes a list of the ports that each node should forward the packet to. In such an embodiment, when a node receives a packet, it routes the packet to the port identified in the header and removes the port from the list. Each node in the network performs the same process [Mehrvar, ¶ [0003]].
Mehrvar further teaches that the source node generates a list of nodes and/or optical links that form a route from source to destination and transmits the list as control information together with payload, and each node reads relevant control information non-destructively while passing remaining control information downstream “[0014] In some embodiments of the disclosure, the source node, having some predetermined knowledge of the network topology, such as a number of nodes in the network and a connectivity of the nodes in the network, generates a list of nodes and/or optical links between nodes that form a route in the network from the source node to the destination node. The nodes in the network do not necessarily need to know the entire route from source node to destination node. Each node simply decodes the control information identifying the next hop in the route towards the destination node. By utilizing the decoded control information identifying the next hop, a switch in the node can be controlled to route the optical signal including the payload and some or all of the control information onto the next optical link toward the destination node. In another embodiment, a network controller has knowledge of the network topology and provides a source routed list to the source node. The use of a controller to create the segment routing list allows for a centralization of the knowledge of the network topology and allows a plurality of nodes to act as source nodes without needing to provide each of them with the network topology. [0015] In some aspects the optical signal may be considered to be a series of photonic frames, or bursts, in which each frame carries all of the routing information needed to route the frame from source node to destination node. Each frame being transmitted from the source node to the destination node includes control information and payload. A portion of the frame containing the control information may be transmitted on a same wavelength channel for all optical links in the network. Alternatively, the control information may be transmitted on multiple dedicated wavelength channels, wherein each dedicated wavelength channel is for a particular optical link of the network. [0016] The list of nodes of the intended route from source to destination forms at least part of the control information that is transmitted by the source node in an optical signal together with payload. Each node in the path receives both the payload and control information. In accordance with the received control information, a node will identify the next hop and forward the payload accordingly. Each node in the route can read the relevant control information, in a manner non-destructive to the control information associated with other nodes in the segment routed path. The expression "in a manner non-destructive to the control information associated with other nodes" is used to convey that the content of the control information associated with other nodes is not fundamentally altered. The present node is able to extract relevant control information and pass the remaining control information to the subsequent nodes. The phrase "relevant control information" should be understood to refer to control information needed by the receiving node. If a segment route defining the link that the signal should be forwarded on at each hop is encoded in the control information, each node will find the link that it should forward the signal on to be relevant, while the routing information intended for other nodes will not be relevant. While in some embodiments described in detail below the control information associated with subsequent nodes is temporarily isolated from the payload as it traverses the switch node or is converted from the optical domain to the electrical domain and then back to the optical domain by the switch node currently receiving the optical signal, the content of the control information associated with the subsequent nodes is not altered” [Mehrvar, ¶ [0014]-¶ [0016]].
Mehrvar further teaches that control information may include routing information including a list of optical links in the segment routed path comprising a plurality of optical switch nodes, the list defining at least a route from a current optical switch node to a destination optical switch node, and may also include management and update information “[0063] The control information may include routing information including a list of optical links in the segment routed path comprising a plurality of optical switch nodes. The list defines at least a route from a current optical switch node to a destination optical switch node. The control information may also include burst mode reset information, source node to intermediate node management and update and/or end- to-end (source node to destination node) management and update information. Management and update information may include, for example, commissioning and software update information” [Mehrvar, ¶ [0063]].
Accordingly, claim 8 is anticipated by Mehrvar.
Claim 9
Mehrvar expressly discloses an optical switch node including a wavelength diverting element configured to divert one or more wavelength channels carrying control information associated with the optical switch node, and a controller configured to read the control information associated with the optical switch node from an optical signal diverted by the wavelength diverting element “[0058] The optical switch node 800 includes a wavelength diverting element 840 optically coupled to the plurality of input ports 810. In some embodiments the wavelength diverting element 840 is an optical filter that acts to divert one or more wavelength channels carrying control information associated with the optical switch node by dropping a wavelength channel carrying the control information associated with the optical switch node and passing a payload. In some embodiments the optical filter may pass control information associated with other optical switch nodes in the segment routed path together with the payload. In some embodiments the wavelength diverting element 840 is an optical splitter that acts to direct one or more wavelengths by taping the received optical signal from one or more of the pluralities of input ports 810. In such a scenario not only is the desired wavelength channel carrying the control information associated with the optical switch node diverted by the optical splitter, but the payload and other wavelength channels carrying control information associated with subsequent switch nodes in the designated route as well [Mehrvar, ¶ [0058]].
Mehrvar further teaches that the controller controls the optical switch fabric to direct, to an output port selected in accordance with information carried in the diverted portion of the received signal, the optical signal carrying the payload and control information for subsequent nodes “[0060] The optical switch node 800 includes a controller 830 optically coupled to the wavelength diverting element 840. The controller 830 is configured to read control information associated with the optical switch node 800 from an optical signal diverted from the wavelength diverting element 840 in a manner that is nondestructive to the control information associated with other nodes in the segment routed path. The controller 830 then controls the optical switch fabric 820 to direct, to an output port selected in accordance with information carried in the diverted portion of the received signal, the optical signal carrying the payload and the control information associated with subsequent nodes in a segment routed path” [Mehrvar, ¶ [0060]].
Mehrvar further teaches that the optical switch fabric routes the optical signal (including payload and control information) to one of a plurality of transmitting ports, thereby expressly disclosing selection among multiple output/transmitting ports “[0070] In some embodiments, the source optical switch node further includes the features described above that are found in the intermediate nodes. For example, the optical switch node includes at least one input ports, in which each port is configured to receive from a prior node over a respective optical link in the optical network, an optical signal carrying a payload and control information for all subsequent nodes in a segment routed path. The optical switch node includes a wavelength diverting element optically coupled to the plurality of input ports. The optical switch node may also include an optical switch fabric optically coupled to the plurality of input ports for routing an optical signal including the received payload and control information associated with at least the subsequent optical switch nodes, to one of a plurality of transmitting ports. The controller of the node may also be further configured to read control information in the received optical signal associated with the optical switch node, in a manner non-destructive to the control information associated with other nodes in the segment routed path. The controller of the node may also be further configured to control an optical switch fabric to direct, to an output port selected in accordance with information carried in the diverted portion of the received signal, the optical signal carrying the payload and the control information associated with subsequent nodes in a segment routed path” [Mehrvar, ¶ [0070]].
Accordingly, claim 9 is anticipated by Mehrvar.
Claim 10
Mehrvar teaches that the controller controls the optical switch fabric to route the optical signal to an output port selected in accordance with information carried in the diverted portion of the received signal “[0060] The optical switch node 800 includes a controller 830 optically coupled to the wavelength diverting element 840. The controller 830 is configured to read control information associated with the optical switch node 800 from an optical signal diverted from the wavelength diverting element 840 in a manner that is nondestructive to the control information associated with other nodes in the segment routed path. The controller 830 then controls the optical switch fabric 820 to direct, to an output port selected in accordance with information carried in the diverted portion of the received signal, the optical signal carrying the payload and the control information associated with subsequent nodes in a segment routed path” [Mehrvar, ¶ [0060]].
Mehrvar further teaches that the optical switch fabric routes the optical signal (including payload and control information) to one of a plurality of transmitting ports, thereby expressly disclosing selection among multiple output/transmitting ports “[0070] In some embodiments, the source optical switch node further includes the features described above that are found in the intermediate nodes. For example, the optical switch node includes at least one input ports, in which each port is configured to receive from a prior node over a respective optical link in the optical network, an optical signal carrying a payload and control information for all subsequent nodes in a segment routed path. The optical switch node includes a wavelength diverting element optically coupled to the plurality of input ports. The optical switch node may also include an optical switch fabric optically coupled to the plurality of input ports for routing an optical signal including the received payload and control information associated with at least the subsequent optical switch nodes, to one of a plurality of transmitting ports. The controller of the node may also be further configured to read control information in the received optical signal associated with the optical switch node, in a manner non-destructive to the control information associated with other nodes in the segment routed path. The controller of the node may also be further configured to control an optical switch fabric to direct, to an output port selected in accordance with information carried in the diverted portion of the received signal, the optical signal carrying the payload and the control information associated with subsequent nodes in a segment routed path” [Mehrvar, ¶ [0070]]. Accordingly, claim 10 is anticipated by Mehrvar.
Claim Rejections – 35 U.S.C. § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for the obviousness rejections set forth in this Office Action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
As reiterated by the Supreme Court in KSR, and as set forth in MPEP 2141 (R-01.2024), II, the factual inquiries of Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), applied for establishing a background for determining obviousness under 35 U.S.C. §103, are summarized as follows:
Determining the scope and content of the prior art;
Ascertaining the differences between the prior art and the claims at issue;
Resolving the level of ordinary skill in the pertinent art; and
Considering objective evidence indicative of obviousness or non-obviousness, if present.
This application currently names joint inventors. In considering patentability of the claims, the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 C.F.R. § 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. § 102(b)(2)(C) for any potential 35 U.S.C. § 102(a)(2) prior art against the later invention.
Claims 1, 2, 3, 4, 9, 10 and 16 are rejected under 35 U.S.C. §103 as being unpatentable over Kato et al. (EP1499077B1) in view of Blumenthal et al., Journal of Lightwave Technology, and in further view of Wing (US20020109879A1).
Claim 1
Kato teaches an optical packet routing system having a plurality of communication nodes and a routing device (router) coupled via optical transmission lines, where nodes transmit optical signals and optical label signals carrying routing/control information “[0001] The present invention relates to an optical packet routing system for routing an optical signal by using the optical label signal carrying the control information necessary for the routing of the optical signal, more particularly, to a multiple-wavelength optical source unit to be used for a network system whose a plurality of communication nodes are connected by the wavelength routing system and an optical communication unit and an optical communication method to be used for an optical communication system whose internode communication among the communication nodes is made through a routing unit…… [0005] The communication nodes 100a-100d are respectively provided with one of the corresponding optical signal transmitters 71a-71d for respectively transmitting one of the corresponding optical signals 76a-76d and also respectively provided with one of the corresponding optical label signal transmitters 72a-72d for respectively transmitting one of the corresponding optical label signals 77a-77d carrying the control information necessary for the routing of the optical signal. [0006] The routing device 80 is connected respectively to each communication nodes 100a-100d through the corresponding optical transmission lines 81a-81d and comprises wavelength demultiplexers 74 for separating the optical signals and the optical label signals, optical receivers 78e for receiving the optical label signals separated by the wavelength multiplexers 74, optical splitters 79 for branching the optical signals separated by the wavelength demultiplexers 74 to a plurality of optical paths and a plurality of optical gates 75a-75d for selecting the optical path by the routing processing for passing or intercepting the optical signals according to the control information in the optical label signals 77a-77d respectively connected to a plurality of the corresponding optical paths. The control circuit section for controlling the optical gates 75a-75d are not shown in the figure. [0007] When the optical signals 76a-76d and the optical label signals 77a-77d respectively including the control routing information of the optical signals are fed respectively to the router 80 through the optical transmission lines 81a-81d after being transmitted respectively from a plurality of communication nodes 100a-100d (the four communication nodes #1-#4 in the case shown in the figure), the optical signals 76a-76d and the optical label signals 77a-77d are respectively separated by the wavelength demultiplexers 74 provided in the router 80 respectively corresponding to the communication nodes. [0008] Further, the optical signals 76a-76d are respectively branched by the optical splitter 79 in the stage following the wavelength demultiplexer 74 and respectively introduced into the corresponding optical gates (three optical gates among the optical gates 75a-75d in the case shown in the figure) through a plurality of optical paths of substantially the same length (three optical paths in the case shown in the figure). On the other hand, the optical label signals 77a-77d are respectively guided to the corresponding optical receivers 78e. Next, when the optical signal passes one or a plurality of optical gates among a plurality of optical gates 75a-75d, which is or are designed to be driven according to the information carried by the optical label signal received by the optical receiver 78e, the optical path for the optical signal is selected from among the optical paths 82a-82d” [Kato, ¶ [0001]; ¶ [0005]-¶ [0008]].
Kato further teaches that the routing device includes wavelength demultiplexers that separate optical signals and optical label signals, optical receivers that receive the separated optical label signals, optical splitters that branch the optical signals into a plurality of optical paths, and optical gates that select a path by passing/intercepting the optical signals according to the control information in the optical label signals “[0006] The routing device 80 is connected respectively to each communication nodes 100a-100d through the corresponding optical transmission lines 81a-81d and comprises wavelength demultiplexers 74 for separating the optical signals and the optical label signals, optical receivers 78e for receiving the optical label signals separated by the wavelength multiplexers 74, optical splitters 79 for branching the optical signals separated by the wavelength demultiplexers 74 to a plurality of optical paths and a plurality of optical gates 75a-75d for selecting the optical path by the routing processing for passing or intercepting the optical signals according to the control information in the optical label signals 77a-77d respectively connected to a plurality of the corresponding optical paths. The control circuit section for controlling the optical gates 75a-75d are not shown in the figure. [0007] When the optical signals 76a-76d and the optical label signals 77a-77d respectively including the control routing information of the optical signals are fed respectively to the router 80 through the optical transmission lines 81a-81d after being transmitted respectively from a plurality of communication nodes 100a-100d (the four communication nodes #1-#4 in the case shown in the figure), the optical signals 76a-76d and the optical label signals 77a-77d are respectively separated by the wavelength demultiplexers 74 provided in the router 80 respectively corresponding to the communication nodes. [0008] Further, the optical signals 76a-76d are respectively branched by the optical splitter 79 in the stage following the wavelength demultiplexer 74 and respectively introduced into the corresponding optical gates (three optical gates among the optical gates 75a-75d in the case shown in the figure) through a plurality of optical paths of substantially the same length (three optical paths in the case shown in the figure). On the other hand, the optical label signals 77a-77d are respectively guided to the corresponding optical receivers 78e. Next, when the optical signal passes one or a plurality of optical gates among a plurality of optical gates 75a-75d, which is or are designed to be driven according to the information carried by the optical label signal received by the optical receiver 78e, the optical path for the optical signal is selected from among the optical paths 82a-82d [Kato, ¶ [0006]-¶ [0008]].
However within analogous art, Blumenthal teaches transmitting label information together with the packet on the same optical wavelength, including subcarrier-multiplexed labels in which a baseband label is modulated onto an RF subcarrier and multiplexed with the IP packet on the same wavelength “…...The method of coding the label onto a packet impacts the channel bandwidth efficiency, the transmission quality of the packet and label, and the best method to wavelength convert the packet and optically swap the label. Two approaches to optical label coding are the serial label [7], [8] and the optical subcarrier multiplexed label [3], [9]-[11], as illustrated in Fig. 3. With serial coding a fixed bit rate label is multiplexed at the head of the IP packet with the two separated by an optical guard-band (OGB) as shown in Fig. 3(a). The OGB is use to facilitate label removal and reinsertion without static packet buffering and to accommodate finite switching times of optical switching and wavelength conversion. The bit-serial label is encoded on the same optical wavelength as the IP packet and is encoded as a baseband signal. For optical subcarrier multiplexed labels, a baseband label is modulated onto a RF subcarrier and then multiplexed with the IP packet on the same wavelength [see Fig. 3(b)]. This multiplexing may be performed electronically or optically as described in [2]-[4], [12]-[14]. An OGB is not necessary in the subcarrier case since the label is transmitted in parallel with the packet. It is only necessary that the label fit within the boundaries of the packet, however an OGB may be used if accumulated misalignment of the label and payload occurs during multiple hops…….” [Blumenthal, p.3].
Additionally, Wing teaches providing network configuration/control information by encoding and modulating a data-carrying optical signal such that the optical signal carries both data and control information, and later network elements demodulate/decode the control to determine control commands “[0006] A method and system for providing network configuration and control information. The configuration and control information are encoded and used to modulate the data-carrying optical Signal. Later network elements demodulate and decode the data to determine configuration and control commands and requests. According to one embodiment of the present invention, a method of providing network configuration data is provided. The method comprises receiving a data-carrying optical Signal; providing control information; modulating the data-carrying optical Signal using the control information Such that the optical Signal carries both the data and the control information; and transmitting the modulated optical Signal. A Spatial light modulator, typically a micromirror array, may be used to modulate the optical signal” [Wing, ¶ [0006].
Wing also defines an optical layer cross-connect (OXC) as a switching element that connects an optical channel from an input port to an output port, and discloses switch operations including “Switch output port.” “[0106] An Optical layer cross-connect is a Switching element that connects an optical channel from an input port to an output port. These devices are also often referred to as optical cross-connects (OXC). Note that an optical add-drop multiplexer (OADM) can be viewed as a simple OXC. The Switching fabric in an OXC may be either electronic or optical. If the Switching fabric is electronic, then Switching would occur at a given channel rate, but the interface ports may in fact be at higher rates (e.g. multiplex multiple channels onto a single wavelength). It is important to note that because of the multiplexing function assumed in the OXC, we do not restrict the light paths to be identical to the Och defined in ITU-T G.872……[0277] (d) Switch (old input link, old input channel, new input link, new input channel, output link, output channel): [0278] Switch output port from the currently connected input channel on the input link to the new input channel on the new input link. The Switch primitive is equivalent to atomically implementing a Disconnect (old input channel, old input link, output channel, output link) followed by a Connect (new input link, new input channel, output link, output channel) [Wing, ¶ [0106]; ¶ [0277]-¶ [0278]].
Accordingly, it would have been obvious to a person of ordinary skill in the art (POSITA) that a POSITA would have been motivated to modify Kato’s label-based router so that the switching identifier information is transported “together with” the optical signal in-band (e.g., as subcarrier label or co-channel modulation) because Kato itself identifies a practical deficiency when label and payload use different wavelengths: wavelength dispersion causes the relative time lag between label and payload to vary with transmission distance, requiring cumbersome per-node timing adjustment and undermining robustness in a network with nodes at different distances. Blumenthal provides a well-established solution to exactly this class of problem by encoding the label on the same optical wavelength as the packet, including subcarrier multiplexing where the label is transmitted in parallel with the packet on the same wavelength, thereby reducing sensitivity to relative delay between separate wavelengths and improving multi-hop compatibility. Wing similarly teaches embedding control information by modulation on the data-carrying optical signal so downstream elements can demodulate/decode it to derive control commands, which predictably reduces dependency on separate control channels and enables faster distributed switching decisions. A POSITA would also be motivated to implement Kato’s “optical gate selection” as (or in combination with) conventional optical switching elements because OXC-type switching is the standard, predictable mechanism for connecting an input port to a selected output port based on decoded control, and Wing expressly defines this behavior and provides switching primitives including “Switch output port.”. Combining these teachings uses each reference for its established purpose (Kato: label-controlled routing architecture; Blumenthal/Wing: in-band label/control encoding; Wing: port-selection switching semantics) and yields the expected result of reliable output-port selection with reduced timing calibration burden, with a reasonable expectation of success under KSR.
Therefore, the combination teaches transmitting switching identifier/control information with the optical signal, detecting/determining the identifier/control information at a downstream node (label receiver/demodulation via a branched/demultiplexed path), and controlling optical switching/gating to select one of multiple output paths/ports based on the determined content of the identifier/control information, as recited in claim 1.
Claim 2
With respect to claim 2, all limitations of claim 1 are taught by Kato, Blumenthal and Wing, except wherein claim 2 additionally requires that the identifier information is transmitted together with the optical signal as (i) modulation of the optical signal; or (ii) an optical sideband/subcarrier using a spectral fraction of the spectral transmission width.
Added: “the segment optical switching identifier information is transmitted together with the optical signal as a modulation of the optical signal; or the segment optical switching identifier information is transmitted together with the optical signal as an optical sideband, spectrally neighboring the optical signal, wherein the optical sideband uses a spectral fraction of the overall spectral transmission width of or associated or assigned to the optical signal.” However, within analogous art, Kato explicitly highlights that dispersion-induced variation of relative time lag is problematic when label and payload are separated by wavelength, so a POSITA would reasonably select these in-band methods as predictable improvements to reduce timing adjustment complexity and improve robustness.
Within analogous art, Blumenthal expressly teaches the sideband/subcarrier alternative by modulating a baseband label onto an RF subcarrier and multiplexing it with the packet on the same wavelength “…...The method of coding the label onto a packet impacts the channel bandwidth efficiency, the transmission quality of the packet and label, and the best method to wavelength convert the packet and optically swap the label. Two approaches to optical label coding are the serial label [7], [8] and the optical subcarrier multiplexed label [3], [9]-[11], as illustrated in Fig. 3. With serial coding a fixed bit rate label is multiplexed at the head of the IP packet with the two separated by an optical guard-band (OGB) as shown in Fig. 3(a). The OGB is use to facilitate label removal and reinsertion without static packet buffering and to accommodate finite switching times of optical switching and wavelength conversion. The bit-serial label is encoded on the same optical wavelength as the IP packet and is encoded as a baseband signal. For optical subcarrier multiplexed labels, a baseband label is modulated onto a RF subcarrier and then multiplexed with the IP packet on the same wavelength [see Fig. 3(b)]. This multiplexing may be performed electronically or optically as described in [2]-[4], [12]-[14]. An OGB is not necessary in the subcarrier case since the label is transmitted in parallel with the packet. It is only necessary that the label fit within the boundaries of the packet, however an OGB may be used if accumulated misalignment of the label and payload occurs during multiple hops…….” [Blumenthal, p.3].
Additionally, Wing expressly teaches the modulation alternative by encoding control information and using it to modulate the data-carrying optical signal so that the optical signal carries both data and control information “[0006] A method and system for providing network configuration and control information. The configuration and control information are encoded and used to modulate the data-carrying optical Signal. Later network elements demodulate and decode the data to determine configuration and control commands and requests. According to one embodiment of the present invention, a method of providing network configuration data is provided. The method comprises receiving a data-carrying optical Signal; providing control information; modulating the data-carrying optical Signal using the control information Such that the optical Signal carries both the data and the control information; and transmitting the modulated optical Signal. A Spatial light modulator, typically a micromirror array, may be used to modulate the optical signal” [Wing, ¶ [0006].
Accordingly, it would have been obvious to a person of ordinary skill in the art (POSITA) that a POSITA would have been motivated to implement Kato’s routing/control information transport using either (a) co-channel modulation (Wing) or (b) subcarrier/sideband label coding (Blumenthal) because both are established physical-layer techniques for ensuring that switching identifier information co-propagates with payload through the optical network. Wing’s modulation approach predictably enables downstream decoding of control commands without requiring a separate label wavelength that can drift relative to payload due to dispersion. Blumenthal’s RF subcarrier label approach likewise keeps the label on the same optical wavelength as the payload while allowing relatively simple narrowband extraction, and is particularly compatible with multi-hop systems where repeated label extraction and forwarding occur.
The combination is a straightforward substitution of known signaling techniques for their known purpose (carry control with payload), and would have been implemented with a reasonable expectation of success under KSR.
Claim 3
With respect to claim 3, all limitations of claim 1 are taught by Kato, Blumenthal and Wing, except wherein claim 3 additionally requires an optical switching element having an input port and first/second output ports and a processing/control element that controls the switching element to select the output port. However, within analogous art, Kato teaches branching the optical signal via an optical splitter into a plurality of optical paths feeding a plurality of optical gates, and selecting one path by driving the corresponding optical gate according to control information decoded from the optical label signal “[0006] The routing device 80 is connected respectively to each communication nodes 100a-100d through the corresponding optical transmission lines 81a-81d and comprises wavelength demultiplexers 74 for separating the optical signals and the optical label signals, optical receivers 78e for receiving the optical label signals separated by the wavelength multiplexers 74, optical splitters 79 for branching the optical signals separated by the wavelength demultiplexers 74 to a plurality of optical paths and a plurality of optical gates 75a-75d for selecting the optical path by the routing processing for passing or intercepting the optical signals according to the control information in the optical label signals 77a-77d respectively connected to a plurality of the corresponding optical paths. The control circuit section for controlling the optical gates 75a-75d are not shown in the figure. [0007] When the optical signals 76a-76d and the optical label signals 77a-77d respectively including the control routing information of the optical signals are fed respectively to the router 80 through the optical transmission lines 81a-81d after being transmitted respectively from a plurality of communication nodes 100a-100d (the four communication nodes #1-#4 in the case shown in the figure), the optical signals 76a-76d and the optical label signals 77a-77d are respectively separated by the wavelength demultiplexers 74 provided in the router 80 respectively corresponding to the communication nodes. [0008] Further, the optical signals 76a-76d are respectively branched by the optical splitter 79 in the stage following the wavelength demultiplexer 74 and respectively introduced into the corresponding optical gates (three optical gates among the optical gates 75a-75d in the case shown in the figure) through a plurality of optical paths of substantially the same length (three optical paths in the case shown in the figure). On the other hand, the optical label signals 77a-77d are respectively guided to the corresponding optical receivers 78e. Next, when the optical signal passes one or a plurality of optical gates among a plurality of optical gates 75a-75d, which is or are designed to be driven according to the information carried by the optical label signal received by the optical receiver 78e, the optical path for the optical signal is selected from among the optical paths 82a-82d [Kato, ¶ [0006]-¶ [0008]].
Additionally, Wing teaches an OXC as a switching element that connects an optical channel from an input port to an output port, and that optical switching is achieved by configuring such switching elements “[0106] An Optical layer cross-connect is a Switching element that connects an optical channel from an input port to an output port. These devices are also often referred to as optical cross-connects (OXC). Note that an optical add-drop multiplexer (OADM) can be viewed as a simple OXC. The Switching fabric in an OXC may be either electronic or optical. If the Switching fabric is electronic, then Switching would occur at a given channel rate, but the interface ports may in fact be at higher rates (e.g. multiplex multiple channels onto a single wavelength). It is important to note that because of the multiplexing function assumed in the OXC, we do not restrict the light paths to be identical to the Och defined in ITU-T G.872” [Wing, ¶ [0106].
Accordingly, it would have been obvious to a person of ordinary skill in the art (POSITA) that a POSITA would have been motivated to express and implement Kato’s path-selection mechanism as a conventional “optical switching element + controller/processing” architecture because deployed optical networks routinely use OXCs/switch fabrics as the physical switching substrate, with a controller that maps decoded control information to a specific input-to-output port configuration. Kato already discloses the exact functional loop: the label is separated and received, control information is analyzed, and the appropriate gate/path is selected by driving the gate accordingly. Implementing this selection using a switch fabric with explicit ports yields predictable engineering benefits (clear port-based abstraction, scalable to more than two outputs, and compatibility with existing OXC control-plane semantics) without changing the fundamental principle of operation (selection based on decoded identifier). This is a routine design choice that a POSITA would make to integrate Kato’s label-controlled routing into conventional optical switching hardware, with a reasonable expectation of success under KSR.
Claim 4
With respect to claim 4, all limitations of claim 1 are taught by Kato, Blumenthal and Wing, except wherein claim 4 additionally requires branching off a control signal from the optical signal via a splitter element, processing the control signal, and transmitting a control command to configure the optical switching element. However, within analogous art, Kato teaches separating an optical label signal (control information) from the optical signal using wavelength demultiplexers and receiving the label at optical receivers for routing processing “…..[0007] When the optical signals 76a-76d and the optical label signals 77a-77d respectively including the control routing information of the optical signals are fed respectively to the router 80 through the optical transmission lines 81a-81d after being transmitted respectively from a plurality of communication nodes 100a-100d (the four communication nodes #1-#4 in the case shown in the figure), the optical signals 76a-76d and the optical label signals 77a-77d are respectively separated by the wavelength demultiplexers 74 provided in the router 80 respectively corresponding to the communication nodes…….” [Kato, ¶ [0006]-¶ [0008]].
Kato also teaches branching the optical signal via an optical splitter into a plurality of optical paths feeding optical gates “[0006] The routing device 80 is connected respectively to each communication nodes 100a-100d through the corresponding optical transmission lines 81a-81d and comprises wavelength demultiplexers 74 for separating the optical signals and the optical label signals, optical receivers 78e for receiving the optical label signals separated by the wavelength multiplexers 74, optical splitters 79 for branching the optical signals separated by the wavelength demultiplexers 74 to a plurality of optical paths and a plurality of optical gates 75a-75d for selecting the optical path by the routing processing for passing or intercepting the optical signals according to the control information in the optical label signals 77a-77d respectively connected to a plurality of the corresponding optical paths. The control circuit section for controlling the optical gates 75a-75d are not shown in the figure” [Kato, ¶ [0006]].
Accordingly, it would have been obvious to a person of ordinary skill in the art (POSITA) that a POSITA would have been motivated to implement the claimed “probe branch/splitter + processing + control command” structure because it is the standard way to realize label-based switching in the optical domain: extract sufficient control/label information on a branch that can be processed (optical receiver + logic), then drive the switching element (gate/switch fabric) via a control command so the payload proceeds along the selected path. Kato already uses a separated label path (demultiplexer + optical receiver) for label processing and uses the result to drive gate selection, which is functionally the same as generating a control command to configure a switching element. Moreover, in-band label/control encoding (Blumenthal/Wing) makes this extraction-and-control loop even more predictable because the control information remains co-propagating with payload, simplifying the timing of when the control command must be applied. Thus, it would have been obvious to implement claim 4’s control-branch processing and switching configuration as a routine implementation of Kato’s router functionality, with a reasonable expectation of success under KSR.
Claim 9
Kato teaches a routing device (router) that receives optical signals and corresponding optical label signals, separates them via wavelength demultiplexers, receives the label via optical receivers, branches the optical signal via optical splitters into multiple paths, and selects a path by driving optical gates according to the control information carried by the optical label signal, which corresponds to a segment destination optical node configured to detect/determine identifier information and select an output path/port based on that information “[0006] The routing device 80 is connected respectively to each communication nodes 100a-100d through the corresponding optical transmission lines 81a-81d and comprises wavelength demultiplexers 74 for separating the optical signals and the optical label signals, optical receivers 78e for receiving the optical label signals separated by the wavelength multiplexers 74, optical splitters 79 for branching the optical signals separated by the wavelength demultiplexers 74 to a plurality of optical paths and a plurality of optical gates 75a-75d for selecting the optical path by the routing processing for passing or intercepting the optical signals according to the control information in the optical label signals 77a-77d respectively connected to a plurality of the corresponding optical paths. The control circuit section for controlling the optical gates 75a-75d are not shown in the figure. [0007] When the optical signals 76a-76d and the optical label signals 77a-77d respectively including the control routing information of the optical signals are fed respectively to the router 80 through the optical transmission lines 81a-81d after being transmitted respectively from a plurality of communication nodes 100a-100d (the four communication nodes #1-#4 in the case shown in the figure), the optical signals 76a-76d and the optical label signals 77a-77d are respectively separated by the wavelength demultiplexers 74 provided in the router 80 respectively corresponding to the communication nodes. [0008] Further, the optical signals 76a-76d are respectively branched by the optical splitter 79 in the stage following the wavelength demultiplexer 74 and respectively introduced into the corresponding optical gates (three optical gates among the optical gates 75a-75d in the case shown in the figure) through a plurality of optical paths of substantially the same length (three optical paths in the case shown in the figure). On the other hand, the optical label signals 77a-77d are respectively guided to the corresponding optical receivers 78e. Next, when the optical signal passes one or a plurality of optical gates among a plurality of optical gates 75a-75d, which is or are designed to be driven according to the information carried by the optical label signal received by the optical receiver 78e, the optical path for the optical signal is selected from among the optical paths 82a-82d” [Kato, ¶ [0006]-¶ [0008]].
However, within analogous art, Blumenthal and Wing teach that label/control information can be carried together with the optical signal on the same wavelength (subcarrier label or co-channel control modulation) and decoded downstream to drive switching control “………. The method of coding the label onto a packet impacts the channel bandwidth efficiency, the transmission quality of the packet and label, and the best method to wavelength convert the packet and optically swap the label. Two approaches to optical label coding are the serial label [7], [8] and the optical subcarrier multiplexed label [3], [9]–[11], as illustrated in Fig. 3.With serial coding a fixed bit rate label is multiplexed at the head of the IP packet with the two separated by an optical guard-band (OGB) as shown in Fig. 3(a). The OGB is use to facilitate label removal and reinsertion without static packet buffering and to accommodate finite switching times of optical switching and wavelength conversion. The bit-serial label is encoded on the same optical wavelength as the IP packet and is encoded as a baseband signal. For optical subcarrier multiplexed labels, a baseband label is modulated onto a RF subcarrier……... Encapsulation of IP packets using optical labels has advantages in that the contents of the original IP packet are not modified and the label is coded at the same wavelength as the IP packet. In the serial case, erasure and rewriting of the label may be performed independently of the IP packet bit rate, however, timing of the label replacement and possibly erasure process is somewhat time critical……Label recovery, label swapping and packet forwarding are the basic functions handled by the AOLS building blocks, shown in Fig. 4. In a core router or AOLS subnet [see Fig. 4(a)], a burst-mode label recovery module is used to recover label clock and data for processing in electronic routing circuitry without significantly perturbing the through-going optical packet data. The routing circuit maps the incoming label and wavelength to a new label and wavelength based on internal routing tables. The label erasure process may be built into this stage depending on the implementation technology” [Blumenthal, p.3]
“[0006] A method and system for providing network configuration and control information. The configuration and control information is encoded and used to modulate the data-carrying optical Signal. Later network elements demodulate and decode the data to determine configuration and control commands and requests. According to one embodiment of the present invention, a method of providing network configuration data is provided. The method comprises receiving a data-carrying optical Signal; providing control information; modulating the data-carrying optical Signal using the control information Such that the optical Signal carries both the data and the control information; and transmitting the modulated optical Signal. A Spatial light modulator, typically a micromirror array, may be used to modulate the optical signal” [Wing, ¶ [0006]].
It would have been obvious to a person of ordinary skill in the art (POSITA) that a POSITA would have been motivated to implement the claim-9 node using Kato’s concrete router architecture because it provides a direct hardware mapping for detecting identifier information (label receiver) and selecting among multiple output paths (splitter + gates) according to that identifier. Further, a POSITA would be motivated to incorporate in-band label/control encoding (Blumenthal/Wing) to reduce timing/alignment complexity and improve robustness, consistent with Kato’s own teaching that relative delay varies due to dispersion when label and payload use different wavelengths. Thus, the structure and operation recited in claim 9 would have been obvious with a reasonable expectation of success under KSR.
Claim 10
With respect to claim 10, all limitations of claim 9 are taught by Kato, Blumenthal and Wing, except wherein claim 10 additionally requires that the selection of either output port is caused by a processing/control element controlling an optical switching element.
However, within analogous art, Kato teaches that, based on routing processing using control information in the optical label signals, the optical gates select which branched optical path passes the optical signal (the control circuit section for controlling the optical gates is explicitly contemplated) “[0006] The routing device 80 is connected respectively to each communication nodes 100a-100d through the corresponding optical transmission lines 81a-81d and comprises wavelength demultiplexers 74 for separating the optical signals and the optical label signals, optical receivers 78e for receiving the optical label signals separated by the wavelength multiplexers 74, optical splitters 79 for branching the optical signals separated by the wavelength demultiplexers 74 to a plurality of optical paths and a plurality of optical gates 75a-75d for selecting the optical path by the routing processing for passing or intercepting the optical signals according to the control information in the optical label signals 77a-77d respectively connected to a plurality of the corresponding optical paths. The control circuit section for controlling the optical gates 75a-75d are not shown in the figure” [Kato, ¶ [0006]].
Additionally, Wing teaches the switching matrix/controller model for optical switching and defines OXC port-to-port connections “[0106] An Optical layer cross-connect is a Switching element that connects an optical channel from an input port to an output port. These devices are also often referred to as optical cross-connects (OXC). Note that an optical add-drop multiplexer (OADM) can be viewed as a simple OXC. The Switching fabric in an OXC may be either electronic or optical. If the Switching fabric is electronic, then Switching would occur at a given channel rate, but the interface ports may in fact be at higher rates (e.g. multiplex multiple channels onto a single wavelength). It is important to note that because of the multiplexing function assumed in the OXC, we do not restrict the light paths to be identical to the Och defined in ITU-T G.872…… [0363] MPLS traffic engineering control plane model. Architecturally, both LSRs and OXCs emphasize problem decomposition by decoupling the control plane from the data plane. The data plane of an LSR uses the label Swapping paradigm to transfer a labeled packet from an input port to an output port. The data plane of an OXC uses a Switching matrix to connect an optical channel trail from an input port to an output port. [0364] An LSR performs label switching by first establishing a relation between an <input port, input labeled tuple and an <Output port, output labeled tuple. Likewise, an OXC provisions optical channel trails by first establishing a relation between an <input port, input optical channel> tuple and an <output port, output optical channel tuple. These relations are determined by the control plane of the respective network elements, and are locally instantiated on the device through a switch controller. In the LSR, the next hop label forwarding entry (NHLFE) maintains the input-output relations. In the OXC, the Switch controller reconfigures the internal interconnection fabric to establish the relations. These relations cannot be altered by the payload of the data plane” [Wing, ¶ [0363]-¶ [0364]; ¶ [0106]].
Accordingly, it would have been obvious to a person of ordinary skill in the art (POSITA) that a POSITA would have been motivated to represent Kato’s gate-control selection as a processing/control element controlling a switching element because this is the conventional architectural decomposition used in optical switching systems: (i) a controller/processor interprets control information and (ii) a switch fabric (or gate array) is configured accordingly to connect an input to a selected output. Wing explicitly describes this control plane model for optical switching, including a switching matrix whose interconnection fabric is configured by a controller to establish the required input/output relation. Kato already provides the functional basis (routing processing based on label information drives gate selection), and implementing that routing processing in a processing/control element that issues commands to a switching element is a predictable and routine engineering choice. This yields the expected outcome output-port selection responsive to decoded identifier information without changing the principle of operation and with a reasonable expectation of success under KSR.
Claim 16
Kato expressly teaches that the functions of the system can be realized by program codes stored in a memory (storage medium) and executed by a computer (CPU/MPU), and that the memory storing the program codes constitutes the invention “[0084] Needless to say, the object of the present invention can also be attained by providing the system or the equipment with a memory (or storage medium) storing the program of a software for realizing the function of the embodiment so that the computer (CPU or MPU) of such system or equipment reads out the program codes stored in the memory for the execution of the software. In this case, the program codes read out from the memory are employed for performing the function of previously described embodiments, and the memory storing the program codes constitutes the present invention. For the memory for storing the program codes or the data of variables such as the table or the like, floppy disk, hard disk, optical disk, optical magnetic disk, CD-ROM or the like may be employed” [Kato, ¶ [0084]].
Accordingly, it would have been obvious to a person of ordinary skill in the art (POSITA) that a POSITA would have been motivated to implement the label analysis, routing decision, and switch/gate actuation logic using processor-executable instructions stored on non-transitory memory because these are classic control-plane functions that require configurability, updates (e.g., routing table updates), and integration with other network management functions. Kato explicitly teaches that the disclosed functions can be realized by software program codes stored on memory and executed by a CPU/MPU, which directly supports the claimed CRM form and renders the CRM implementation a predictable and conventional embodiment of the same control logic. Additionally, Wing’s teaching that later network elements demodulate/decode control information to determine control commands further supports that such operations are performed by processing hardware executing control logic. Therefore, claim 16 would have been obvious over Kato in view of Blumenthal/ Wing /Lin, with a reasonable expectation of success under KSR.
Claims 5, 6, 7, 8 and 11 are rejected under 35 U.S.C. §103 as being unpatentable over Kato et al. in view of Blumenthal et al., and in further view of Wing and Lin et al., IEEE Photonics Technology Letters.
Claim 5
With respect to claim 5, all limitations of claim 4 are taught by Kato, Blumenthal and Wing, except wherein claim 5 additionally requires generating a further control signal comprising further identifier/switching instruction information for a next node and adding that further control signal to the optical signal at an output port (e.g., via a coupler/modulator). However, within analogous art, Blumenthal teaches label swapping in an all-optical label swapping (AOLS) router: the routing function computes a new label from an internal routing table, and forwarding includes swapping the original label with a new label while converting the labeled packet to a new wavelength “………. ALL-OPTICAL LABEL SWAPPING (AOLS) An AOLS optical packet core network is illustrated in Fig. 1. IP packets enter the core network at an ingress router and travel multiple hops through the core, exiting at an egress router. Packets are handled within the network by core AOLS routers or AOLS subnets, as described in [2]. Fig. 2 depicts the physical network elements connected by fiber links and the packet routing and forwarding hierarchy. IP packets are generated at the electronic routing layer and processed in an adaptation layer that “encapsulates” IP packets with an optical label without modifying the original packet structure. The adaptation layer also shifts the packet and label to a new wavelength specified by local routing tables. An optical multiplexing layer multiplexes labeled packets onto a shared fiber medium. Several optical multiplexing approaches may be used including insertion directly onto an available WDM channel, packet compression through optical time division multiplexing or time interleaving through optical time division multiplexing [6]. This technique is not limited to IP packets and other packet or cell structures like ATM may also be routed. Once inside the core network, core routers or AOLS subnets [2] perform routing and forwarding functions. The routing function computes a new label and wavelength from an internal routing table given the current label, current wavelength, and fiber port. The routing tables (at egress and core routers) are generated by converting IP addresses into smaller pairs of labels and wavelengths and distributing them across the network much in the same way that multiprotocol label switching (MPLS) is used in today’s IP networks [1]. The forwarding function involves swapping the original label with the new label and physically converting the labeled packet to the new wavelength……” [Blumenthal, p.2].
Additionally, within analogous art, Lin teaches an optical-domain subcarrier label swapping technique in which the subcarrier label is first erased in the optical domain and then the light is remodulated with a new subcarrier label at the same microwave carrier frequency, using an external Mach–Zehnder modulator (MZM) “……Our experimental setup for transmitting, destination, and intermediate switching nodes is shown in Fig. 2. In the transmitting node, a 50-mW 1551-nm DFB-MQW laser and a two- electrode LiNbO external Mach–Zehnder modulator (MZM) with a 3-dB bandwidth of 20 GHz and an insertion loss of 4 dB were used. A bursty 155-Mb/s ASK subcarrier label at 12 GHz was applied to a hybrid coupler whose two outputs have phase shift with respect to each other. These two outputs were then combined with a bursty 2.5-Gb/s data and data invert, respectively, through two-directional couplers. Note that the label and payload bursts were both randomly generated, with each label and payload burst consisting of 20 bits and 53 bytes, respectively. Two lowpass filters (LPFs) with a 3-dB bandwidth of 2.4 GHz were used to prevent the tails of the 2.5-Gb/s NRZ data from interfering with the ASK subcarrier. The two combined NRZ data and ASK subcarrier outputs were then used to drive the two electrodes of the MZM, respectively. Fig. 3(a) shows the spectrum of the transmitted baseband 2.5 Gb/s data and the ASK microwave subcarrier label. In the switching node, the received optical signal was split into three paths. The first path was simply a data payload receiver which consists of a 50- -terminated photodiode, a dc–14-GHz amplifier, and an LPF. The second path was a label receiver which consists of a 50 Ω terminated photodiode….” [Lin, p.1-2; Fig. 2].
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Accordingly, it would have been obvious to a person of ordinary skill in the art (POSITA) that a POSITA would have been motivated to generate and add “further identifier/switching instruction information” at an output because multi-hop label-controlled optical routing requires downstream nodes to receive switching/forwarding information that is locally meaningful for the next hop. Blumenthal explains this directly: core routers compute a new label from routing tables and swap the original label with a new label during forwarding, which corresponds to generating new identifier information for the next portion of the path. Lin provides a concrete optical implementation showing that label erasure and remodulation with a new subcarrier label at an intermediate switching node is feasible, repeatable, and does not require converting the payload to electronics, thereby supporting a predictable coupler/modulator-based reinsertion at the output. A POSITA would combine these teachings with Kato’s path selection because Kato provides the label-controlled switching architecture (separate/receive label, branch payload, select path), while Blumenthal/Lin provide the established mechanism for updating and reapplying downstream label/control information. The combination yields the expected result of forwarding the optical signal with updated next-hop switching instructions, with a reasonable expectation of success under KSR, and improves scalability by allowing each node to operate on locally relevant identifier information rather than a monolithic end-to-end identifier.
Claim 6
With respect to claim 6, all limitations of claim 5 are taught by Kato, Blumenthal, Wing and Lin, except wherein claim 6 additionally requires that the control signal and/or further control signal is amplitude/phase modulated on the optical signal and has frequency(ies) lower than the optical carrier frequency. However, within analogous art, Blumenthal teaches RF subcarrier multiplexed labels carried on the same wavelength as the packet “……The method of coding the label onto a packet impacts the channel bandwidth efficiency, the transmission quality of the packet and label, and the best method to wavelength convert the packet and optically swap the label. Two approaches to optical label coding are the serial label [7], [8] and the optical subcarrier multiplexed label [3], [9]–[11], as illustrated in Fig. 3.With serial coding a fixed bit rate label is multiplexed at the head of the IP packet with the two separated by an optical guard-band (OGB) as shown in Fig. 3(a). The OGB is use to facilitate label removal and reinsertion without static packet buffering and to accommodate finite switching times of optical switching and wavelength conversion. The bit-serial label is encoded on the same optical wavelength as the IP packet and is encoded as a baseband signal. For optical subcarrier multiplexed labels, a baseband label is modulated onto a RF subcarrier and then multiplexed with the IP packet on the same wavelength [see Fig. 3(b)]. This multiplexing may be performed electronically or optically as described in [2]–[4], [12]–[14]. An OGB is not necessary in the subcarrier case since the label is transmitted in parallel with the packet. It is only necessary that the label fit within the boundaries of the packet, however an OGB may be used if accumulated misalignment of the label and payload occurs during multiple hops. Packet transparency is realized by setting a fixed label bit rate and modulation format independent of the packet bit rate. The choice of label bit rate is driven by a combination of factors including the speed of the burst-mode label recovery electronics and the duration of the label relative to the shortest packets at the fastest packet bit rates. Additionally, running the label at a lower bit rate allows the use of lower cost electronics to process the label. The label and packet bits can be encoded using different data formats to facilitate data and clock recovery. For example, if the IP packet is compressed to 40 Gb/s using an RZ data format, the label can be encoded at 2.5 Gb/s using NRZ format. A 20-bit label transmitted at 2.5 Gb/s occupies the same duration as a 40-byte packet transmitted at 40 Gb/s………” [Blumenthal, p.2].
Additionally, Wing teaches intensity modulation (IM) of a synchronization preamble bit and control data bits that are linearly superimposed onto DWDM optical data, where the preamble/control bits modulate frequencies in the range of about 10 kHz to 100 kHz (and possibly up to 1 MHz), which are far below the optical carrier frequency “[0860] DWDM control wavelength has to be synchronized with the data channels. A Synchronization Preamble bit is intensity modulated (IM) at approximately 5 to 15% of optical data extinction ratio onto the Specific optical data channel (lambda). [0861] Each lambda has a unique frequency for the Preamble and Control data bits. IM modulation is linearly superimposed onto DWDM optical data via injection current dithering. Control data bits are digital modulation via binary OOK. [0862] The Preamble is at least one NRZ bit modulating one frequency (lambda ID and packet Sync) in the range of 10 k to 100 kHz (1 MHz possible with higher speed DSP). The Control data is least one NRZ bit modulating same frequency (lambda control). RZ format is shown” [Wing, ¶ [0860]-¶ [0862]].
Within analogous art, Lin further teaches a microwave subcarrier label frequency-division multiplexed with baseband payload and remodulation of a new subcarrier label after erasure “……. Our scheme is based on a subcarrier label (e.g., 155 Mb/s on a microwave carrier) which is frequency-division-multiplexed with a baseband data payload (e.g., 2.5 Gb/s). The subcarrier label swapping is accomplished by first having it erased in the optical domain, and then remodulate the light with a new subcarrier label at the same microwave carrier frequency. To erase the old subcarrier, we took advantage of a notch filter by using the reflective part of a voltage-tunable fiber Fabry–Perot (FFP) filter, as shown in Fig. 1. However, we note that the optical double sidebands (ODSB) of the data payload and subcarrier label are located on both sides of the optical carrier, as illustrated in the lower part of Fig. 1(a). To erase the subcarrier label, both subcarrier sidebands must be notched out. But this requires that the free spectral range (FSR) of the filter be exactly equal to the separation of the two subcarrier sidebands. Furthermore, the notch filter must present a sharp and narrow notch so that the data payload is not affected. Consequently, it is difficult to design and manufacture a FFP filter which satisfies both requirements. To solve this problem, we propose using optical single-sideband (OSSB) modulation technique [4] to transport the subcarrier label, so that the resultant optical spectrum contains only one subcarrier label sideband, as shown in Fig. 1(b). Another important advantage of using OSSB microwave subcarrier label is that, by avoiding the fiber dispersion-induced carrier suppression effect [4], its transmission distance between switching nodes can be more than several hundred kilometers without dispersion compensation. Our experimental setup for transmitting, destination, and intermediate switching nodes is shown in Fig. 2. In the transmitting node, a 50-mW 1551-nm DFB-MQW laser and a two- electrode LiNbO external Mach–Zehnder modulator (MZM) a 3-dB bandwidth of 20 GHz and an insertion loss of 4 dB were used. A bursty 155-Mb/s ASK subcarrier label at 12 GHz was applied to a hybrid coupler whose two outputs have phase shift with respect to each other. These two outputs were then combined with a bursty 2.5-Gb/s data and data invert, respectively, through two-directional couplers. Note that the label and payload bursts were both randomly generated, with each label and payload burst consisting of 20 bits and 53 bytes, respectively. Two lowpass filters (LPFs) with a 3-dB bandwidth of 2.4 GHz were used to prevent the tails of the 2.5-Gb/s NRZ data from interfering with the ASK subcarrier. The two combined NRZ data and ASK subcarrier outputs were then used to drive the two electrodes of the MZM, respectively. Fig. 3(a) shows the spectrum of the transmitted baseband 2.5 Gb/s data and the ASK microwave subcarrier label.……...” [Lin, p.1-2; Fig. 2].
Accordingly, it would have been obvious to a person of ordinary skill in the art (POSITA) that a POSITA would have been motivated to implement the control signal as a low-frequency modulation/subcarrier on the optical carrier because this is a known technique that enables simple, fast extraction of control/identifier information using direct detection and narrowband filtering while leaving the high-speed payload largely undisturbed. Wing explicitly teaches such a design: a preamble/control signal is intensity modulated at low frequencies (10–100 kHz) and superimposed onto DWDM optical data, demonstrating practical implementation and detection feasibility at network elements. Blumenthal and Lin further teach that forwarding labels may be carried as RF/microwave subcarriers on the same wavelength as the packet, which provides a predictable “sideband/subcarrier” implementation that co-propagates with payload and supports multi-hop label processing. Applying these modulation/subcarrier techniques to Kato’s label-controlled switching and to the label-update operation of claim 5 yields predictable improvements in robustness and interoperability: the switching identifier information can be extracted with minimal impairment to payload and can be swapped/updated at intermediate nodes without requiring a separate wavelength channel or tight wavelength-dependent timing alignment. This combination therefore would have been adopted by a POSITA with a reasonable expectation of success under KSR.
Claim 7
With respect to claim 7, all limitations of claim 1 are taught by Kato, Blumenthal and Wing, except wherein claim 7 additionally requires that the optical transmission path comprises a plurality of transmission segments between a global source optical node and a global destination optical node, with intermediate segment nodes along the path.
However, within analogous art, Kato teaches a network of multiple nodes exchanging optical signals via routing processing based on optical label signals “[0005] The communication nodes 100a-100d are respectively provided with one of the corresponding optical signal transmitters 71a-71d for respectively transmitting one of the corresponding optical signals 76a-76d and also respectively provided with one of the corresponding optical label signal transmitters 72a-72d for respectively transmitting one of the corresponding optical label signals 77a-77d carrying the control information necessary for the routing of the optical signal. [0006] The routing device 80 is connected respectively to each communication nodes 100a-100d through the corresponding optical transmission lines 81a-81d and comprises wavelength demultiplexers 74 for separating the optical signals and the optical label signals, optical receivers 78e for receiving the optical label signals separated by the wavelength multiplexers 74, optical splitters 79 for branching the optical signals separated by the wavelength demultiplexers 74 to a plurality of optical paths and a plurality of optical gates 75a-75d for selecting the optical path by the routing processing for passing or intercepting the optical signals according to the control information in the optical label signals 77a-77d respectively connected to a plurality of the corresponding optical paths. The control circuit section for controlling the optical gates 75a-75d are not shown in the figure. [0007] When the optical signals 76a-76d and the optical label signals 77a-77d respectively including the control routing information of the optical signals are fed respectively to the router 80 through the optical transmission lines 81a-81d after being transmitted respectively from a plurality of communication nodes 100a-100d (the four communication nodes #1-#4 in the case shown in the figure), the optical signals 76a-76d and the optical label signals 77a-77d are respectively separated by the wavelength demultiplexers 74 provided in the router 80 respectively corresponding to the communication nodes. [0008] Further, the optical signals 76a-76d are respectively branched by the optical splitter 79 in the stage following the wavelength demultiplexer 74 and respectively introduced into the corresponding optical gates (three optical gates among the optical gates 75a-75d in the case shown in the figure) through a plurality of optical paths of substantially the same length (three optical paths in the case shown in the figure). On the other hand, the optical label signals 77a-77d are respectively guided to the corresponding optical receivers 78e. Next, when the optical signal passes one or a plurality of optical gates among a plurality of optical gates 75a-75d, which is or are designed to be driven according to the information carried by the optical label signal received by the optical receiver 78e, the optical path for the optical signal is selected from among the optical paths 82a-82d” [Kato, ¶ [0005]-¶ [0008]].
Lin further teaches an experimental setup including intermediate switching nodes for subcarrier label swapping, evidencing multi-hop/segmented traversal across multiple optical switching nodes “……In the switching node, the received optical signal was split into three paths. The first path was simply a data payload receiver which consists of a 50- -terminated photodiode, a dc–14-GHz amplifier, and an LPF. The second path was a label receiver which consists of a 50- -terminated photodiode, an 8–12-GHz amplifier, a downconverter with IF frequency at 550 MHz, and an ASK envelope detector. The eye diagram of the received data payload and the bursty 20-bit label are shown in the insets of Fig. 2. The third path was the path where the label swapping took place. The optical signal was reflected by an FFP filter via an optical circulator, so that the old subcarrier label was notched out. The FFP filter had an FSR of 1500 GHz, a finesse of , and a reflection loss of 1.5 dB. Fig. 3(b) shows the after-notching microwave spectra. We can see that the subcarrier label at 12 GHz was suppressed by 25 dB, while the 2.5-Gb/s payload experienced only 2-dB loss. The optical signal which had its subcarrier label suppressed subsequently passed through a polarization controller and another MZM. At the MZM, the optical signal was remodulated with a new ASK subcarrier label, which had the same carrier frequency and optical modulation index (OMI) as those of the old subcarrier label. At the output of the switching node, an EDFA with an output power of 12 dBm was used. Note that the lengths of the first and second fiber spans in Fig. 2 were 48.4 and 47.8 km, respectively. In the destination node, the same data payload and subcarrier label receivers as those in the switching node were used. The bit-error rate (BER) of the payload and the label was measured by a burst-mode BER tester (BERT)….” [Lin, Fig. 2; p.2].
It would have been obvious to a person of ordinary skill in the art (POSITA) that a POSITA would have been motivated to implement label-controlled routing across multiple segments/hops because label-based optical routing is inherently intended for multi-node networks: the purpose of carrying routing/control labels is to allow intermediate nodes to make forwarding decisions, not merely a single fixed router. Kato provides the foundational label-controlled switching architecture, and scaling it to multiple sequential segments is a predictable extension because each intermediate node can perform the same operations (extract/decode label/control, select output path, and forward). Lin confirms that such multi-node operation is practically feasible, showing intermediate switching nodes performing label swapping in a multi-node configuration. Moreover, Blumenthal’s AOLS framework explicitly contemplates networks of core routers performing forwarding based on labels, reinforcing that multi-segment operation is the expected deployment environment. Therefore, a POSITA would have been motivated to apply the combined teachings in a multi-segment path context with a reasonable expectation of success.
Claim 8
With respect to claim 8, all limitations of claim 7 are taught by Kato, Blumenthal, Wing and Lin, except wherein claim 8 additionally requires that the identifier information defines a route and/or is modified/enriched hop-by-hop (at least one of the listed alternatives).
However, within analogous art, Blumenthal teaches that the routing function computes a new label from an internal routing table, and the forwarding function swaps the original label with a new label during forwarding “………. ALL-OPTICAL LABEL SWAPPING (AOLS) An AOLS optical packet core network is illustrated in Fig. 1. IP packets enter the core network at an ingress router and travel multiple hops through the core, exiting at an egress router. Packets are handled within the network by core AOLS routers or AOLS subnets, as described in [2]. Fig. 2 depicts the physical network elements connected by fiber links and the packet routing and forwarding hierarchy. IP packets are generated at the electronic routing layer and processed in an adaptation layer that “encapsulates” IP packets with an optical label without modifying the original packet structure. The adaptation layer also shifts the packet and label to a new wavelength specified by local routing tables. An optical multiplexing layer multiplexes labeled packets onto a shared fiber medium. Several optical multiplexing approaches may be used including insertion directly onto an available WDM channel, packet compression through optical time division multiplexing or time interleaving through optical time division multiplexing [6]. This technique is not limited to IP packets and other packet or cell structures like ATM may also be routed. Once inside the core network, core routers or AOLS subnets [2] perform routing and forwarding functions. The routing function computes a new label and wavelength from an internal routing table given the current label, current wavelength, and fiber port. The routing tables (at egress and core routers) are generated by converting IP addresses into smaller pairs of labels and wavelengths and distributing them across the network much in the same way that multiprotocol label switching (MPLS) is used in today’s IP networks [1]. The forwarding function involves swapping the original label with the new label and physically converting the labeled packet to the new wavelength……” [Blumenthal, p.2].
Further, Lin teaches label swapping where the old subcarrier label is erased in the optical domain and the light is remodulated with a new subcarrier label “Our scheme is based on a subcarrier label (e.g., 155 Mb/s on a microwave carrier) which is frequency-division-multiplexed with a baseband data payload (e.g., 2.5 Gb/s). The subcarrier label swapping is accomplished by first having it erased in the optical domain, and then remodulate the light with a new subcarrier label at the same microwave carrier frequency. To erase the old subcarrier, we took advantage of a notch filter by using the reflective part of a voltage-tunable fiber Fabry–Perot (FFP) filter, as shown in Fig. 1. However, we note that the optical………..from interfering with the ASK subcarrier. The two combined NRZ data and ASK subcarrier outputs were then used to drive the two electrodes of the MZM, respectively. Fig. 3(a) shows the spectrum of the transmitted baseband 2.5 Gb/s data and the ASK microwave subcarrier label……….” [Lin, p.1-2].
Accordingly, it would have been obvious to a person of ordinary skill in the art (POSITA) that a POSITA would have been motivated to modify/enrich switching identifier information hop-by-hop because hop-by-hop label significance is the core scalability principle of label-switched routing: each node only needs to interpret locally relevant identifier information and can replace it with a new locally relevant identifier for the next hop. Blumenthal explains that a router computes a new label from a routing table using the current label/wavelength/port context and swaps the original label with the new label during forwarding. Lin provides an optical-domain technique enabling exactly this behavior without disturbing payload erase the old subcarrier label and remodulate a new one demonstrating predictable feasibility for repeated updates across multiple nodes. Applying these known label update principles to Kato’s label-controlled switching yields the expected result of hop-by-hop identifier update (meeting at least one of claim 8’s alternatives), improves network scalability, and reduces the need for a static end-to-end identifier, with a reasonable expectation of success under KSR.
Claim 11
With respect to claim 11, all limitations of claim 9 are taught by Kato, Blumenthal and Wing, except wherein claim 11 additionally requires a coupler/modulator adding a further segment optical switching identifier information at an output port.
However, within analogous art, Blumenthal teaches label swapping where a new label is computed and substituted during forwarding “II. ALL-OPTICAL LABEL SWAPPING (AOLS), An AOLS optical packet core network is illustrated in Fig. 1. IP packets enter the core network at an ingress router and travel multiple hops through the core, exiting at an egress router. Packets are handled within the network by core AOLS routers or AOLS subnets, as described in [2] ………… Once inside the core network, core routers or AOLS subnets [2] perform routing and forwarding functions. The routing function computes a new label and wavelength from an internal routing table given the current label, current wavelength, and fiber port. The routing tables (at egress and core routers) are generated by converting IP addresses into smaller pairs of labels and wavelengths and distributing them across the network much in the same way that multiprotocol label switching (MPLS) is used in today’s IP networks [1]. The forwarding function involves swapping the original label with the new label and physically converting the labeled packet to the new wavelength. Other switching or buffering mechanisms (space, time, etc.) are also…….” [Blumenthal, p.2].
Additionally, Lin teaches erasing an old subcarrier label and remodulating the optical signal with a new subcarrier label using an external Mach–Zehnder modulator, i.e., adding further identifier/control information for downstream forwarding “……. Our scheme is based on a subcarrier label (e.g., 155 Mb/s on a microwave carrier) which is frequency-division-multiplexed with a baseband data payload (e.g., 2.5 Gb/s). The subcarrier label swapping is accomplished by first having it erased in the optical domain, and then remodulate the light with a new subcarrier label at the same microwave carrier frequency. To erase the old subcarrier, we took advantage of a notch filter by using the reflective part of a voltage-tunable fiber Fabry–Perot (FFP) filter, as shown in Fig. 1. However, we note that the optical double sidebands (ODSB) of the data payload and subcarrier label are located on both sides of the optical carrier, as illustrated in the lower part of Fig. 1(a). To erase the subcarrier label, both subcarrier sidebands must be notched out. But this requires that the free spectral range (FSR) of the filter be exactly equal to the separation of the two subcarrier sidebands. Furthermore, the notch filter must present a sharp and narrow notch so that the data payload is not affected. Consequently, it is difficult to design and manufacture a FFP filter which satisfies both requirements. To solve this problem, we propose using optical single-sideband (OSSB) modulation technique [4] to transport the subcarrier label, so that the resultant optical spectrum contains only one subcarrier label sideband, as shown in Fig. 1(b). Another important advantage of using OSSB microwave subcarrier label is that, by avoiding the fiber dispersion-induced carrier suppression effect [4], its transmission distance between switching nodes can be more than several hundred kilometers without dispersion compensation. Our experimental setup for transmitting, destination, and intermediate switching nodes is shown in Fig. 2. In the transmitting node, a 50-mW 1551-nm DFB-MQW laser and a two- electrode LiNbO external Mach–Zehnder modulator (MZM) a 3-dB bandwidth of 20 GHz and an insertion loss of 4 dB were used. A bursty 155-Mb/s ASK subcarrier label at 12 GHz was applied to a hybrid coupler whose two outputs have phase shift with respect to each other. These two outputs were then combined with a bursty 2.5-Gb/s data and data invert, respectively, through two-directional couplers. Note that the label and payload bursts were both randomly generated, with each label and payload burst consisting of 20 bits and 53 bytes, respectively. Two lowpass filters (LPFs) with a 3-dB bandwidth of 2.4 GHz were used to prevent the tails of the 2.5-Gb/s NRZ data from interfering with the ASK subcarrier. The two combined NRZ data and ASK subcarrier outputs were then used to drive the two electrodes of the MZM, respectively. Fig. 3(a) shows the spectrum of the transmitted baseband 2.5 Gb/s data and the ASK microwave subcarrier label.……...” [Lin, p.1-2; Fig. 2].
Accordingly, it would have been obvious to a person of ordinary skill in the art (POSITA) that a POSITA would have been motivated to add/replace identifier information at an output port because downstream switching decisions require the presence of appropriate next-hop identifier information, and it is well known in label-switched optical networks that labels are updated as packets traverse the network. Blumenthal describes this as computing a new label from routing tables and swapping the original label with the new label while forwarding. Lin supplies a specific optical-domain mechanism showing that the old subcarrier label can be erased and a new label can be remodulated on the same optical carrier using a modulator at an intermediate switching node. Combining these teachings with Kato’s label-controlled selection architecture yields predictable multi-hop behavior in which each node can both select its output path and ensure downstream nodes receive updated identifier information, with a reasonable expectation of success under KSR.
It is noted that any citations to specific, pages, columns, lines, or figures in the prior art references and any interpretation of the reference should not be considered to be limiting in any way. A reference is relevant for all it contains and may be relied upon for all that it would have reasonably suggested to one having ordinary skill in the art. See MPEP 2123.
Conclusion
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/MOHAMMED ABDELRAHEEM/Examiner, Art Unit 2635
/DAVID C PAYNE/Supervisory Patent Examiner, Art Unit 2635