CN110620964B

CN110620964B - Optical node architecture using MxN wavelength selective switches

Info

Publication number: CN110620964B
Application number: CN201910528505.8A
Authority: CN
Inventors: P.科尔伯恩; B.史密斯
Original assignee: Lumentum Operations LLC
Current assignee: Lumentum Operations LLC
Priority date: 2018-06-19
Filing date: 2019-06-18
Publication date: 2022-05-10
Anticipated expiration: 2039-06-18
Also published as: CN110620964A

Abstract

A colorless, directionless, contention-free optical network using an mxn wavelength selective switch. The first configuration of the optical node may include a set of degrees, each degree including an inbound Wavelength Selective Switch (WSS) and an outbound WSS. The first configuration may include a first degree extension including a first inbound extension WSS and a first outbound extension WSS. The extension input of the first inbound extension WSS may be connected to the extension output of a second outbound extension WSS included in the second degree extension of the second configuration of the optical node. The extension output of the first outbound extension WSS may be connected to an extension input of a second inbound extension WSS included in a second degree extension of the second configuration. Signals input to the inbound WSS of a given one of the set of degrees can be routed to any drop port included in the second configuration via the first degree extension and the second degree extension.

Description

Optical node architecture using MxN wavelength selective switches

Technical Field

The present disclosure relates to an optical node architecture, and more particularly, to an optical node architecture that implements colorless, directionless, contentionless (CDC) add/drop of optical signals using a group of M × N Wavelength Selective Switches (WSSs).

Background

Optical nodes (e.g., nodes in Dense Wavelength Division Multiplexed (DWDM) optical communication systems) may be capable of colorless, directionless, contention-free (CDC) add/drop. Colorless add/drop refers to the wavelength flexibility of an optical node that allows for adding/dropping any wavelength (i.e., "color") at any add/drop port of the optical node. Directionless add/drop refers to the directional flexibility of an optical node that allows channels (added channels) that are added to be routed to any direction served by the optical node, or allows incoming channels (incoming channels) from any direction served by the optical node to be routed to a given drop port. Contention-free add/drop refers to port flexibility of an optical node that allows multiple add/drop ports of the optical node to send or receive channels of the same wavelength. In such a CDC optical node, multiple wavelengths may be switched to multiple fiber directions, and multiple wavelength channels of the same wavelength may be simultaneously routed between the transmitter/receiver of the optical node and the destination outgoing/inbound (inbound) fiber of the optical node. Thus, a CDC-capable optical node may have improved flexibility and/or ease of operation compared to an optical node that is not capable of performing CDC add/drop.

Disclosure of Invention

According to some possible embodiments, and the optical node may comprise: d (D is more than or equal to 2) input ports; d output ports; and D degrees, each of the D degrees including an inbound MxN (M ≧ D, N ≧ 2D) Wavelength Selective Switch (WSS) and an outbound (outbound) MxN WSS, wherein each inbound MxN WSS can include: an input connected to a respective (respctive) input port of the D input ports, D-1 common inputs connected to D-1 drop outputs, each drop output being a respective inbound mxn WSS at the other degree, D-1 express outputs connected to D-1 express inputs, each express input being a respective outbound mxn WSS at the other degree, D-1 drop outputs connected to D-1 common inputs, each common input being a respective inbound mxn WSS at the other degree, and at least one local drop port, and wherein each outbound mxn WSS can include: an output connected to a respective output port of the D input ports, a D-1 common output connected to D-1 inbound inputs, each outbound input at a respective M N WSS of the other degree, D-1 express inputs connected to D-1 express outputs, each inbound M N WSS of the other degree, a D-1 inbound input connected to D-1 common outputs, each outbound M N WSS of the other degree, and at least one local inbound port.

According to some possible embodiments, the optical node may comprise: d (D ≧ 2) input ports, D output ports, and D degrees, wherein each degree includes an inbound MXN (M ≧ D, N ≧ 2D) Wavelength Selective Switch (WSS) associated with the respective input port, and an outbound MXN WSS associated with the respective output port, wherein each inbound MXN WSS can: receiving optical signals from one input port and from other degrees of inbound M × N WSSs, providing optical signals to the other degrees of inbound M × N WSSs for local drop at the other degrees, providing optical signals to the other degrees of outbound M × N WSSs for their respective output ports, and providing optical signals to the local drop ports; and wherein each outbound mxn WSS may: receive optical signals from other degrees of inbound M × N WSS and from other degrees of outbound M × N WSS for their respective output ports, receive optical signal ports from the local add port for their respective output ports, and provide optical signals from the local add port to other degrees of outbound M × N WSS for their respective output ports.

According to some possible embodiments, the optical node architecture may include: d (D is more than or equal to 2) input ports and D output ports; and D degrees, each degree including an inbound MXN (M ≧ D, N ≧ 2D) Wavelength Selective Switch (WSS) and an outbound MXN WSS, wherein each inbound MXN WSS can include: an input connected to a respective input port, a set of inputs connected to a set of outputs, a respective inbound mxn WSS for each output at the other degree, a set of outputs connected to a set of inputs, a respective outbound mxn WSS for each input at the other degree, a set of outputs connected to a set of inputs, a respective inbound mxn WSS for each input at the other degree, and at least one local drop port, and wherein each outbound mxn WSS can comprise: an output coupled to a respective output port, a set of outputs coupled to a set of inputs, a respective outbound mxn WSS for each input at the other degree, a set of inputs coupled to a set of outputs, a respective inbound mxn WSS for each output at the other degree, a set of inputs coupled to a set of outputs, a respective outbound mxn WSS for each output at the other degree, and at least one local ingress port.

According to some possible embodiments, the optical node may comprise a configuration comprising: d (D ≧ 1) degrees, each of the D degrees including an inbound Wavelength Selective Switch (WSS) and an outbound WSS; and E (E ≧ 1) degree extensions, each degree extension of the E degree extensions including an inbound extension WSS and an outbound extension WSS, wherein the inbound extension WSS included in the degree extension of the E degree extension includes: an extension input connected to an extension output of an outbound extension WSS, the outbound extension WSS included in a first other configuration of degree extensions of the optical node; d common inputs connected to D drop outputs, each drop output at a respective inbound WSS of D degrees; d fast outputs connected to D fast inputs, each fast input at a respective outbound WSS of D degrees; d drop outputs connected to D common inputs, each common input at a respective inbound WSS of D degrees; and at least one local drop port, wherein an outbound extension WSS included in a degree extension of the E degree extension includes: an extension output connected to an extension input of an inbound extension WSS, the inbound extension WSS being included in a degree extension of the second other configuration of the optical node; d common outputs connected to D add inputs, each add input at a respective output WSS of D degrees; d fast inputs connected to D fast outputs, each fast output at a respective inbound WSS of D degrees; d add inputs connected to D common outputs, each common output at a respective outbound WSS of D degrees; and at least one local add port, and wherein a signal input to an inbound WSS of a given one of the D degrees can be routed to any drop port included in the second other configuration of optical nodes via a degree extension of the E degree extensions.

According to some possible embodiments, the optical node may comprise a first configuration comprising: d1(D1 ≧ 1) degrees, each of the D1 degrees including an inbound WSS and an outbound WSS; and a first degree extension comprising a first inbound extension WSS and a first outbound extension WSS, wherein the first inbound extension WSS comprises an extension input connected to an extension output of a second outbound extension WSS comprised in a second degree extension of the second configuration, and wherein the first outbound extension WSS comprises an extension output connected to an extension input of a second inbound extension WSS comprised in a second degree extension of the second configuration; and a second configuration comprising: d2(D2 ≧ 1) degrees, each of the D2 degrees including an inbound WSS and an outbound WSS; a second degree extension including a second extension inbound WSS and a second extension outbound WSS, wherein the second inbound extension WSS includes an extension input connected to the extension output of the first outbound extension WSS, wherein the second outbound extension WSS includes an extension output connected to the extension input of the first inbound extension WSS, wherein a signal input to a given one of D1 degrees inbound WSS can be routed to any drop port included in the second configuration via the first degree extension and the second degree extension, and wherein a signal input to a given one of D2 degrees inbound WSS can be routed to any drop port included in the first configuration via the second degree extension and the first degree extension.

According to some possible embodiments, the optical node may comprise a first configuration comprising: a set of degrees, each degree comprising an inbound WSS and an outbound WSS; and a first degree extension comprising a first inbound extension WSS and a first outbound extension WSS, wherein an extension input of the first inbound extension WSS is connected to an extension output of a second outbound extension WSS comprised in a second degree extension of the second configuration of the optical node, and wherein an extension output of the first outbound extension WSS is connected to an extension input of a second inbound extension WSS comprised in the second degree extension of the second configuration, wherein a signal input to a given one of the set of degrees can be routed to any downstream port comprised in the second configuration via the first degree extension and the second degree extension, and wherein a signal input to a given one of the other set of degrees can be routed to any downstream port comprised in the first configuration via the second degree extension and the first degree extension.

Drawings

Fig. 1 is a diagram of a prior art optical node capable of implementing CDC add/drop using a set of multicast switches (MCSs) associated with add/drop optical signals and WSSs layered, paired WSSs associated with inbound and outbound transport fibers.

Fig. 2 is a diagram of an example optical node capable of implementing CDC add/drop using a single-layer mxn WSS.

FIGS. 3A and 3B are exemplary functional diagrams of an inbound M N WSS and an outbound M N WSS, respectively, included in the exemplary optical node of FIG. 2; and

fig. 4A and 4B are diagrams of example optical nodes capable of implementing CDC add/drop using a single-layer mxn WSS while providing add/drop port extensions (expansion).

Fig. 5-7 are diagrams associated with an example optical node configured to implement CDC add/drop using an mxn WSS while supporting scaling to beyond M degrees.

Detailed Description

The following detailed description of example embodiments refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. The embodiments described below are merely examples and are not intended to limit the embodiments to the precise forms disclosed. Rather, the embodiments are chosen and described to enable a person of ordinary skill in the art to practice the embodiments.

Prior art optical nodes may implement CDC add/drop using an architecture that includes pairs of Wavelength Selective Switches (WSSs), each pair of WSSs being associated with a different degree (degree, D), layered with sets of multicast switches (MCS) and/or WSSs connected to the add/drop ports of the optical node, and in some cases layered with optical amplifiers (e.g., such that optical amplification is required when insertion loss is high). Fig. 1 is a diagram of a prior art optical node 100, which optical node 100 is capable of implementing CDC add/drop using a hierarchical, paired WSS of a set of MCSs and WSSs associated with add/drop optical signals.

As shown in FIG. 1, a prior art optical node 100 includes a set of degrees 102-1 through 102-X (X > 1). As shown, each degree 102 includes a multiplexing demultiplexing stage 104 (e.g., 104-1 to 104-X) and an optical channel monitor 106 (e.g., 106-1 to 106-X). As further shown, each multiplexing/demultiplexing stage 104 contains a pair of WSSs 108 (e.g., WSS 108-1A and WSS 108-1B through WSS 108-XA and WSS 108-XB). As shown, the first WSS 108 (e.g., WSS 108-1A, WSS 108-XA) in each pair is coupled to an input fiber (e.g., 150-1, 150-X) associated with a respective degree 102, while the second WSS (e.g., WSS 108-1B, WSS 108-XB) in each pair is coupled to an output fiber (e.g., 155-1, 155-X) associated with a respective degree 102.

As further shown, the prior art optical node 100 includes an add/drop stage 120 and/or an add/drop stage 140. As shown, the add/drop stage 120 contains a set of WSSs 122 (e.g., WSS 122-1 and WSS 122-2). As shown, a first WSS 122 (e.g., WSS 122-1) associated with a drop optical signal at the prior art optical node 100 may be coupled to a set of optical Receivers (RX) 128. Although not shown, in some cases, the first WSS 122 may be coupled to a set of splitters (splitter), which are coupled to the set of optical Receivers (RX) 128. Similarly, a second WSS 122 (e.g., WSS 122-2) associated with an on-route optical signal at the prior art optical node 100 may be coupled to a set of optical Transmitters (TX) 130. Although not shown, in some cases, the second WSS 122 may be coupled to a set of couplers, where the set of couplers is coupled to the set of optical Transmitters (TX) 130. As further shown in FIG. 1, add/drop stage 140 includes a set of multicast switches (MCSs) 142 (e.g., MCS 142-1 and MCS 142-2). As shown, a first MCS 142 (e.g., MCS 142-1) associated with a drop optical signal at the prior art optical node 100 is coupled to a set of optical Receivers (RX)144, while a second MCS 142 (e.g., MCS 142-2) associated with an add optical signal at the prior art optical node 100 is coupled to a set of optical Transmitters (TX) 146.

The degree 102 connects the prior art optical node 100 bi-directionally to another optical node or end node (endpoint node) of, for example, a DWDM optical communication system. For example, WSS 108-1A may receive an input signal from another optical node via an optical fiber. Here, if a portion of the input signal (e.g., one or more wavelength channels) is to be dropped, WSS 108-1A may selectively provide the portion of the input signal (e.g., an optical signal containing one or more wavelength channels) on a drop path to one or more optical receivers 128 (e.g., a path from WSS 108-1A to one or more optical receivers 128 via WSS 122-1 and splitter 124) or on a drop path to one or more optical receivers 144 (e.g., a path from WSS 108-1A to one or more optical receivers 144 via MCS 142-1). Furthermore, if a portion of the input signal is to continue on the outgoing fiber of another degree 102 (i.e., not dropped), WSS 108-1A may selectively provide the portion of the input signal on an express path (e.g., a path from WSS 108-1A to WSS 108-XB) to the outbound WSS 108 associated with the other degree 102.

As another example, WSS 108-1B may provide an output signal to another optical node via an optical fiber. Here, the WSS 108-1B may receive optical signals uplinked at the prior art optical node 100 on an uplinked path from the optical transmitter 130 (e.g., a path from the optical transmitter 130 to the WSS 108-1B via the coupler 126 and the WSS 122-2) or on an uplinked path from the optical transmitter 146 (e.g., a path from the optical transmitter 146 to the WSS 108-1B via the MCS 142-2) and provide an output signal containing the optical signals via the optical fiber. Similarly, WSS 108-1B may receive a portion of an input signal on a fast path from an inbound WSS 108 (e.g., WSS 108-XA) associated with another degree 102 and may provide an output signal containing the portion of the input signal via an optical fiber. In the prior art optical node 100, any wavelength may be switched to any fiber direction (i.e., any degree), and multiple channels of the same wavelength may be routed simultaneously between the transmitter/receiver of the prior art optical node 100 and the target outgoing/incoming fiber of the prior art optical node 100. In other words, the prior art optical node 100 may be capable of performing CDC add/drop.

However, while the prior art optical node 100 may be capable of CDC add/drop, the cost, complexity, and/or physical size of the prior art optical node 100 may be undesirable due to the need for multiple layers of components (e.g., pairs of WSSs 108 layered with WSSs 122 and/or MCSs 142). The embodiments described herein provide an architecture with a single layer of components for implementing CDC add/drop optical nodes, i.e., a single M N WSS (M ≧ D, N ≧ 2D) connected to each inbound fiber and each outbound fiber. An optical node implementing the CDC using a single layer assembly has reduced cost, complexity, and/or physical size as compared to a prior art optical node implementing the CDC on/off (e.g., prior art optical node 100).

Fig. 2 is a diagram of an example optical node 200 capable of implementing CDC add/drop using a single-layer mxn WSS. As shown in fig. 2, the optical node 200 may include pairs of mxn WSSs 205 and 250, where each mxn WSS205 and 250 includes any outbound port, or subset of outbound ports to a device, capable of independently routing any wavelength channel from any inbound port to the device, as described in further detail below.

In some embodiments, each pair of M × N WSS 205/250 is associated with a different degree of optical node 200. The optical node 200 contains a total of D degrees (D ≧ 2), where each of the D degrees contains an inbound MXN WSS205 and an outbound MXN WSS 250(M ≧ D, N ≧ 2D). For example, as shown in FIG. 2, degree D1 may include an inbound MXN WSS 205-1 and an outbound MXN WSS 250-1, and degree D2 may include an inbound MXN WSS205-2 and an outbound MXN WSS 250-2. In some implementations, the inbound mxn WSS205 and the outbound mxn WSS 250 associated with a given degree may be included in a "dual" WSS (referred to herein as a dual mxn WSS 205/250), where the inbound mxn WSS205 and the outbound mxn WSS 250 are optically independent WSSs arranged in the same physical space and possibly sharing certain optical components.

Note that while fig. 2 shows only two degrees (D1 and D2) and the associated mxn WSS 205/250, the optical node 200 may contain one or more additional degrees (each with respective inbound and outbound mxn WSS205 and 250). For example, although only two degrees are shown in fig. 2, the mxn WSS 205/250 shown in fig. 2 is capable of supporting an optical node 200 that includes four degrees (e.g., D1 through D4).

As shown in fig. 2, the inbound mxn WSS205 may include an input port 305, a set of Common Inputs (CI)310, a set of local drop ports 325, a set of Drop Outputs (DO)330, and a set of fast outputs (EO) 335.

The input port 305 (e.g., input port 305-1 of the mxn WSS 205-1, input port 305-2 of the mxn WSS 205-2) is a port of the inbound mxn WSS205 via which the inbound mxn WSS205 may receive an input signal associated with a degree of correspondence via an optical fiber (e.g., from another optical node). In some embodiments, as shown in fig. 2, one of the M ports 302 (as identified in fig. 3A) of the inbound mxn WSS205 is configured as an input port 305. For example, one of the M ports 302 of the M N WSS 205-1 (one of the ports shown to the left of the M N WSS 205-1 in FIG. 2) is configured as an input port 305-1 via which the M N WSS 205-1 may receive an input signal associated with degree D1 via an optical fiber. As another example, one of the M ports 302 of the M N WSS205-2 (one of the ports shown to the right of the M N WSS205-2 in FIG. 2) is configured as an input port 305-2 via which the M N WSS205-2 may receive an input signal associated with degree D2 via an optical fiber. Although not shown, additional inbound mxn WSSs 205 associated with degrees D3 and D4 may be similarly configured with input ports 305.

In some embodiments, the input port 305 of the inbound mxn WSS205 is configured such that optical signals can be routed from the input port 305 to any local drop port 325 of the inbound mxn WSS 205. For example, input port 305-1 may be configured such that an optical signal received at input port 305-1 may be routed to any one of the set of local drop ports 325-1. As another example, the input port 305-2 of the M N WSS205-2 may be configured such that an optical signal received at the input port 305-2 may be routed to any one of the set of local drop ports 325-2. Additional details regarding local drop port 325 are described below.

In some embodiments, the input port 305 of the inbound mxn WSS205 is configured such that an optical signal can be routed from the input port 305 to any drop output 330 of the inbound mxn WSS205 (i.e., when the optical signal is to be dropped at a local drop port of another WSS 205). For example, the M N WSS 205-1 may be configured such that an optical signal received at the input port 305-1 may be routed to any one of the set of drop outputs 330-1. As another example, the input port 305-2 of the M N WSS205-2 may be configured such that an optical signal received at the input port 305-2 may be routed to any one of the set of drop ports 330-2. Additional details regarding the drop output 330 are described below.

In some embodiments, the input port 305 of the inbound mxn WSS205 is configured such that an optical signal can be routed from the input port 305 to any fast output 335 of the inbound mxn WSS205 (i.e., when the optical signal is to be provided via another degree). For example, input port 305-1 may be configured such that an optical signal received at input port 305-1 may be routed to any one of the set of fast outputs 335-1. As another example, the input port 305-2 of the M N WSS205-2 may be configured such that an optical signal received at the input port 305-2 may be routed to any one of the set of fast outputs 335-2. Additional details regarding fast output 335 are described below.

The set of common inputs 310 (e.g., identified as CI 310-1 for the M N WSS 205-1 and CI 310-2 for the M N WSS 205-2) is a set of inputs of the inbound M N WSS205 for receiving optical signals to be dropped at a degree associated with the inbound M N WSS205 (i.e., dropped at the inbound M N WSS 205's local drop port 325). In some embodiments, as shown in fig. 2, a subset of the M ports 302 of the inbound mxn WSS205 is configured as the set of common inputs 310. In some embodiments, the set of common inputs 310 is connected to the downstream outputs 330 of other inbound mxn WSSs 205 associated with other degrees. In some embodiments, the set of common inputs 310 includes D-1 inputs.

For example, a subset of the M ports 302 of the M N WSS 205-1 (e.g., the three ports shown to the left of the M N WSS 205-1 in FIG. 2) are configured as a common input 310-1, and the M N WSS 205-1 may receive an optical signal via the common input 310-1 to be dropped at a degree D1 (i.e., at the local drop port 325-1 of the M N WSS 205-1). As shown, the common input 310-1 is connected to the downstream output 330-2 of the inbound MXN WSS205-2 associated with degree D2. Although not shown, the other common input 310-1 is connected to the downstream output 330 of the inbound M N WSS205 associated with degrees D3 and D4.

As another example, a subset of the M ports 302 of the M N WSS205-2 (e.g., the three ports shown to the right of the M N WSS205-2 in FIG. 2) are configured as a common input 310-2, and the M N WSS205-2 may receive optical signals via the common input 310-2 to be dropped at a degree D2 (i.e., at the local drop port 325-2 of the M N WSS 205-2). As shown, the common input 310-2 is connected to the downstream output 330-1 of the inbound MXN WSS 205-1 associated with degree D1. Although not shown, the other common input 310-2 is connected to the downstream output 330 of the inbound M N WSS205 associated with degrees D3 and D4.

In some embodiments, the set of common inputs 310 of the inbound mxn WSS205 is configured such that optical signals can be routed from any common input 310 of the inbound mxn WSS205 to any local drop port 325 of the inbound mxn WSS 205. For example, each common input 310-1 of the M N WSS 205-1 may be configured such that an optical signal received at any one of the set of common inputs 310-1 may be routed to any one of the set of local drop ports 325-1. As another example, each common input 310-2 of the M N WSS205-2 may be configured such that optical signals received at any one of the set of common inputs 310-2 may be routed to any one of the set of local drop ports 325-2.

The set of local drop ports 325 (e.g., local drop ports 325-1 of the mxn WSS 205-1, local drop ports 325-2 of the mxn WSS 205-2) is the set of ports via which optical signals can be dropped at a given degree (e.g., provided to an optical receiver at a given degree). In some embodiments, a subset of the N ports 322 (as identified in fig. 3A) of the inbound mxn WSS205 is configured as the set of local drop ports 325. For example, the local drop port 325-1 of the inbound MXN WSS 205-1 may comprise a set of N ports 322 of the MXN WSS 205-1 via which optical signals may be dropped at D1. As another example, the local drop port 325-2 of the inbound MXN WSS205-2 may include a set of N ports 322 of the MXN WSS205-2 via which optical signals may drop at D2. In some embodiments, the set of local drop ports may include N-2D +2 drop ports. In some embodiments, optical signals may be routed from input port 305 and/or from any common input 310 to any local drop port 325, as described above.

The set of drop outputs 330 (e.g., identified as DO 330-1 for the M N WSS 205-1 and DO 330-2 for the M N WSS 205-2) is a set of outputs of the inbound M N WSS205 for providing optical signals to be dropped at the local drop ports 325 of the other inbound M N WSS 205. In some embodiments, a subset of the N ports 322 of the inbound mxn WSS205 is configured as the set of downstream outputs 330. In some embodiments, the set of downstream outputs 330 is connected to the common inputs 310 of other inbound mxn WSSs 205 associated with other degrees. In some embodiments, the set of drop outputs 330 includes D-1 outputs.

For example, a subset of the N ports 322 of the M N WSS 205-1 (e.g., the three ports shown to the right of the M N WSS 205-1 in FIG. 2) are configured as drop outputs 330-1, and the M N WSS 205-1 may provide optical signals to be dropped at other degrees via the drop outputs 330-1 (i.e., at the local drop port 325-2 of the inbound M N WSS 205-2). As shown, the drop output 330-1 is connected to the common input 310-2 of the inbound MXN WSS205-2 associated with degree D2. Although not shown, the other drop outputs 330-1 are connected to the common input 310 of the inbound MXN WSS205 associated with degrees D3 and D4.

As another example, a subset of the N ports 322 of the M N WSS205-2 (e.g., the three ports shown to the right of the M N WSS205-2 in FIG. 2) are configured as drop outputs 330-2, and the M N WSS205-2 may provide optical signals via the drop outputs 330-2 to be dropped at other degrees (i.e., at the local drop port 325-1 of the inbound M N WSS 205-1). As shown, the drop output 330-2 is connected to the common input 310-1 of the inbound MXN WSS 205-1 associated with degree D1. Although not shown, the other drop outputs 330-2 are connected to the common input 310 of the inbound MXN WSS205 associated with degrees D3 and D4.

In some embodiments, the set of downstream outputs 330 of the inbound mxn WSS205 is configured such that optical signals can be routed from the input port 305 of the inbound mxn WSS205 to any downstream output 330 of the inbound mxn WSS 205. For example, each drop output 330-1 of the M N WSS 205-1 may be configured such that an optical signal received at the input port 305-1 may be routed to any one of the set of drop outputs 330-1. As another example, each drop output 330-2 in the M N WSS205-2 may be configured such that an optical signal received at the input port 305-2 may be routed to any one of the set of drop outputs 330-2.

A set of fast outputs 335 (e.g., identified as EO 335-1 for mxn WSS 205-1 and EO 335-2 for mxn WSS 205-2) is a set of outputs of the inbound mxn WSS205 for providing optical signals to be transmitted through the optical node 200 (i.e., optical signals that are not dropped at the optical node 200). In some embodiments, a subset of the N ports 322 of the inbound mxn WSS205 is configured as the set of fast outputs 335. In some embodiments, the set of fast outputs 335 are connected to fast inputs 385 of the outbound mxn WSS 250 associated with other degrees. In some embodiments, the set of fast outputs 335 contains D-1 outputs. Additional details regarding the quick input 385 are described below.

For example, a subset of the N ports 322 of the M × N WSS 205-1 (e.g., the three ports shown on the right side of the M × N WSS 205-1 in fig. 2) are configured as fast outputs 335-1, and the M × N WSS 205-1 may provide optical signals via the fast outputs 335-1 to be transmitted through the optical node 200 and at other degrees (i.e., via the respective output ports 355). As shown, the fast output 335-1 is connected to the fast input 385-2 of the outbound MXN WSS 250-2 associated with the degree D2. Although not shown, the other fast output 335-1 is connected to the fast input 385 of the outbound mxn WSS 250 associated with the degrees D3 and D4.

As another example, a subset of the N ports 322 of the M × N WSS205-2 (e.g., the three ports shown to the left of the M × N WSS205-2 in fig. 2) are configured as fast outputs 335-2, and the M × N WSS205-2 may provide optical signals via the fast outputs 335-2 that will pass through the optical node 200 and be transmitted at other degrees (i.e., via the respective output ports 355). As shown, the fast output 335-2 is connected to the fast input 385-1 of the outbound MXN WSS 250-1 associated with the degree D1. Although not shown, the other fast output 335-2 is connected to the fast input 385 of the outbound mxn WSS 250 associated with the degrees D3 and D4.

In some embodiments, the set of fast outputs 335 of the inbound mxn WSS205 is configured such that optical signals can be routed from the input port 305 of the inbound mxn WSS205 to any fast output 335 of the inbound mxn WSS 205. For example, the set of fast outputs 335-1 of the M N WSS 205-1 may be configured such that an optical signal received at the input port 305-1 may be routed to any one of the set of fast outputs 335-1. As another example, the set of fast outputs 335-2 of the M N WSS205-2 may be configured such that an optical signal received at the input port 305-2 may be routed to any one of the set of fast outputs 335-2.

As further shown in fig. 2, the outbound mxn WSS 250 may contain an output port 355, a set of Common Outputs (COs) 360, a set of local add ports 375, a set of Add Inputs (AIs) 380, and a set of fast inputs (EI) 385.

The output port 355 (e.g., output port 355-1 of the mxn WSS 250-1, output port 355-2 of the mxn WSS 250-2) is a port of the outbound mxn WSS 250 via which the outbound mxn WSS 250 can provide (e.g., to another optical node) an output signal associated with the degree of correspondence via an optical fiber. In some embodiments, as shown in fig. 2, one of the M ports 352 (as identified in fig. 3B) of the outbound mxn WSS 250 is configured as an output port 355. For example, one of the M ports 352 of the M N WSS 250-1 (one of the ports shown to the left of the M N WSS 250-1 in FIG. 2) is configured as an output port 355-1 via which output port 355-1, the M N WSS 250-1 may provide an output signal associated with degree D1 via optical fiber. As another example, one of the M ports 352 of the M N WSS 250-2 (one of the ports shown to the right of the M N WSS 250-2 in FIG. 2) is configured as an output port 355-2 via which the M N WSS 250-2 may provide an output signal associated with degree D2 via optical fiber. Although not shown, additional outbound mxn WSSs 250 associated with degrees D3 and D4 may be similarly configured with an output port 355.

In some embodiments, the output port 355 of the outbound mxn WSS 250 is configured such that optical signals can be routed from any local add port 375 of the outbound mxn WSS 250 to the output port 355 (i.e., when optical signals are to be transmitted from the degree to which the optical signals are added). For example, output port 355-1 may be configured such that an optical signal may be routed from any one of the set of local add ports 375-1 to output port 355-1 for transmission on an output optical fiber associated with degree D1. As another example, output port 355-2 may be configured such that an optical signal may be routed from any one of the set of local add ports 375-2 to output port 355-2 for transmission on an output optical fiber associated with degree D2. Additional details regarding local add-on port 375 are described below.

In some implementations, the output port 355 of the outbound mxn WSS 250 is configured such that the optical signal can be routed from any add input 380 of the outbound mxn WSS 250 to the output port 355 (e.g., when the optical signal is added at another degree and provided via the degree associated with the outbound mxn WSS 250). For example, output port 355-1 may be configured such that an optical signal may be routed from any one of the set of add inputs 380-1 to output port 355-1 for transmission on an output optical fiber associated with degree D1. As another example, output port 355-2 may be configured such that an optical signal may be routed from any one of the set of add inputs 380-2 to output port 355-2 for transmission on an output fiber associated with D2 degrees. Additional details regarding add input 380 are described below.

In some embodiments, the output port 355 of the outbound mxn WSS 250 is configured such that optical signals can be routed from any fast input 385 of the outbound mxn WSS 250 to the output port 355. For example, the output port 355-1 may be configured such that an optical signal may be routed from any one of the set of fast inputs 385-1 to the output port 355-1. As another example, the output port 355-2 can be configured such that an optical signal can be routed from any one of the set of fast inputs 385-2 to the output port 355-2. Additional details regarding the quick input 385 are described below.

The set of common outputs 360 (e.g., identified as CO 360-1 for M × N WSS 250-1 and CO 360-2 for M × N WSS 250-2) is a set of outputs of the outbound M × N WSS 250 for providing optical signals to be transmitted via the outbound M × N WSS 250 associated with the other degree (i.e., optical signals to be provided via the output ports 355 associated with the other degree). In some embodiments, as shown in fig. 2, a subset of the M ports 352 of the outbound mxn WSS 250 is configured as the set of common outputs 360. In some embodiments, the set of common outputs 360 is connected to the add inputs 380 of other outbound mxn WSSs 250 associated with other degrees. In some embodiments, the set of common outputs 360 includes D-1 outputs.

For example, a subset of the M ports 352 of the M N WSS 250-1 (e.g., the three ports shown to the left of the M N WSS 250-1 in FIG. 2) are configured as a common output 360-1, via which the M N WSS 250-1 may provide optical signals to be transmitted at the degrees D2, D3, and/or D4 (i.e., via the respective output port 355 associated with each other degree). As shown, the common output 360-1 is connected to the add input 380-2 of the outbound MXN WSS 250-2 associated with degree D2. Although not shown, the other common output 360-1 is connected to the add input 380 of the outbound MXN WSS 250 associated with degrees D3 and D4.

As another example, a subset of the M ports 352 of the M x N WSS 250-2 (e.g., the three ports shown to the right of the M x N WSS 250-2 in fig. 2) are configured as a common output 360-2, via which common output 360-2 the M x N WSS 250-2 may provide optical signals to be transmitted at the degrees D1, D3, and/or D4 (i.e., via the respective output port 355 associated with each other degree). As shown, the common output 360-2 is connected to the add input 380-1 of the outbound MXN WSS 250-1 associated with degree D1. Although not shown, the other common output 360-2 is connected to the add input 380 of the outbound MXN WSS 250 associated with degrees D3 and D4.

In some embodiments, the set of common outputs 360 of the outbound mxn WSS 250 is configured such that optical signals can be routed from any local add port 375 of the outbound mxn WSS 250 to any common output 360 of the mxn WSS 250. For example, the set of common outputs 360-1 of the M N WSS 250-1 may be configured such that optical signals may be routed from any one of the set of local add ports 375-1 to any one of the set of common outputs 360-1. As another example, the set of common outputs 360-2 of the M N WSS 250-2 may be configured such that optical signals may be routed from any one of the set of local add ports 375-2 to any one of the set of common outputs 360-2.

A set of local add ports 375 (e.g., local add port 375-1 of mxn WSS 250-1, local add port 375-2 of mxn WSS 250-2) is a set of ports via which optical signals may be added (e.g., received from an optical transmitter, to be transmitted to one of output ports 355 of an optical node). In some embodiments, a subset of the N ports 372 (as identified in fig. 3B) of the outbound mxn WSS 250 is configured as the set of local inbound ports 375. For example, local add port 375-1 of outbound MXN WSS 250-1 may comprise a set of N ports 372 of MXN WSS 250-1 via which optical signals may be added at D1. As another example, the local add port 375-2 of the outbound mxn WSS 250-2 may comprise a set of N ports 372 of the mxn WSS 250-2 via which optical signals may be added at D2. In some embodiments, the set of local add ports may include N-2D +2 add ports. In some embodiments, optical signals may be routed from any local add port 375 to output port 355 and/or to any common output 360, as described above.

A set of add inputs 380 (e.g., identified as AI 380-1 for the mxn WSS 250-1 and AI 380-2 for the mxn WSS 250-2) is a set of inputs of the outbound mxn WSS 250 for receiving optical signals to be transmitted at a degree associated with the outbound mxn WSS 250 (i.e., to be provided on an optical fiber via the output port 355 of the outbound mxn WSS 250). In some embodiments, a subset of the N ports 372 of the outbound mxn WSS 250 are configured as the set of add inputs 380. In some embodiments, the set of add inputs 380 are connected to the common outputs 360 of other outbound mxn WSSs 250 associated with other degrees. In some embodiments, the set of add inputs 380 includes D-1 outputs.

For example, a subset of the N ports 372 of the M N WSS 250-1 (e.g., the three ports shown to the right of the M N WSS 250-1 in FIG. 2) are configured as an add input 380-1 via which the M N WSS 250-1 can receive an optical signal to be transmitted at degree D1 (e.g., via output port 355-1). As shown, the add input 380-1 is connected to the common output 360-2 of the outbound MXN WSS 250-2 associated with degree D2. Although not shown, the other add input 380-1 is connected to the common output 360 of the outbound MXN WSS 250 associated with degrees D3 and D4.

As another example, a subset of the N ports 372 of the M x N WSS 250-2 (e.g., the three ports shown to the right of the M x N WSS 250-2 in fig. 2) are configured as an add input 380-2 via which the M x N WSS 250-2 can receive an optical signal to be transmitted at degree D2 (e.g., via output port 355-2). As shown, the add input 380-2 is connected to the common output 360-1 of the outbound MXN WSS 250-1 associated with degree D1. Although not shown, the other add input 380-2 is connected to the common output 360 of the outbound MXN WSS 250 associated with degrees D3 and D4.

In some embodiments, the set of add inputs 380 of the outbound mxn WSS 250 is configured such that optical signals can be routed from any add input 380 of the outbound mxn WSS 250 to the output port 355 of the outbound mxn WSS 250. For example, each add input 380-1 of the M N WSS 250-1 may be configured such that an optical signal may be routed from any one of the set of add inputs 380-1 to the output port 355-1. As another example, each add input 380-2 of the M N WSS 250-2 may be configured such that an optical signal may be routed from any one of the set of add inputs 380-2 to the output port 355-2.

A set of fast inputs 385 (e.g., identified as EI 385-1 for the M x N WSS 250-1 and EI 385-2 for the M x N WSS 250-2) is a set of inputs of the outbound M x N WSS 250 for receiving optical signals to be transmitted through the optical node 200 (i.e., optical signals that do not drop at the optical node 200). In some embodiments, a subset of the N ports 372 of the outbound mxn WSS 250 are configured as the set of fast inputs 385. In some embodiments, the set of fast inputs 385 are connected to fast outputs 335 of the inbound mxn WSS205 associated with other degrees. In some embodiments, the set of fast inputs 385 includes D-1 inputs.

For example, a subset of the N ports 372 of the M × N WSS 250-1 (e.g., the three ports shown on the right side of the M × N WSS 250-1 in fig. 2) are configured as a fast input 385-1 via which the M × N WSS 250-1 can receive an optical signal to be transmitted through the optical node 200 and at degree D1 (i.e., via output port 355-1). As shown, the fast input 385-1 is connected to the fast output 335-2 of the inbound MXN WSS205-2 associated with degree D2. Although not shown, the other fast inputs 385-1 are connected to the fast outputs 335 of the inbound M N WSS205 associated with degrees D3 and D4.

As another example, a subset of the N ports 372 of the M x N WSS 250-2 (e.g., the three ports shown to the left of the M x N WSS 250-2 in fig. 2) are configured as a fast input 385-2 via which the M x N WSS 250-2 can receive an optical signal (i.e., via output port 355-2) to be transmitted through the optical node 200 and at degree D2. As shown, the fast input 385-2 is connected to the fast output 335-1 of the inbound M N WSS 205-1 associated with degree D1. Although not shown, the other fast inputs 385-2 are connected to the fast outputs 335 of the inbound M N WSS205 associated with the degrees D3 and D4.

In some embodiments, the set of fast inputs 385 of the outbound mxn WSS 250 are configured such that optical signals can be routed from any fast input 385 of the outbound mxn WSS 250 to the output port 355 of the outbound mxn WSS 250. For example, the set of fast inputs 385-1 of the M N WSS 250-1 can be configured such that an optical signal can be routed from any one of the set of fast inputs 385-1 to the output port 355-1. As another example, the set of fast inputs 385-2 of the mxn WSS 250-2 can be configured such that an optical signal can be routed from any one of the set of fast inputs 385-2 to the output port 355-2.

In this manner, the optical node 200 may be able to implement CDC functionality using a single layer of M × N WSS 205. For example, any optical signal may be routed to any output fiber or may be down-routed to any receiver connected to any mxn WSS at optical node 200 without wavelength contention (i.e., multiple instances of each wavelength may be routed independently). Furthermore, any optical signal provided by a transmitter of a given mxn WSS can be routed to any output fiber without wavelength contention.

In some embodiments, paths within a given mxn WSS 205/250 of the optical node 200 and/or connections between mxn WSS 205/250 of the optical node 200 may be configurable and/or reconfigurable by a controller (not shown) associated with the optical node 200.

As shown in fig. 2, some optical signals may pass through only one mxn WSS 205/250. For example, an optical signal dropped at the local drop port 325-1 of the M N WSS 205-1 received via the input port 305-1 of the M N WSS 205-1 passes only through the M N WSS 205-1. However, other optical signals may pass through both mxn WSSs 205. For example, an optical signal received via input port 305-1 of M N WSS 205-1 dropped at local drop port 325-2 of M N WSS205-2 passes through M N WSS 205-1 and M N205-2. As a result, these optical signals may experience different amounts of insertion loss. This can be compensated for by increasing the attenuation of the optical signal passing through only one mxn WSS 205/250 so that the power levels of all optical signals are approximately equal.

In addition, the optical signal supplied via the fast path can have a high isolation (high isolation). In other words, the wavelength of the drop can be removed in order to avoid interference with the optical signal of the same wavelength of the subsequent add. This may require selecting which ports to use as fast outputs 335 and/or fast inputs 385 in order to optimize isolation. In some cases, a particular port location may need to remain unused. For example, ports corresponding to-1 order diffraction angles for each fast output 335 and/or fast input 385, or other port locations that may cause crosstalk into fast outputs 335 and/or fast inputs 385, may need to remain unused. In some embodiments, the insertion loss may be low enough that no optical amplifier is needed between the mxn WSS 205/250.

The number and arrangement of elements shown and described in connection with fig. 2 are provided as examples. In practice, the optical node 200 may contain additional degrees and/or WSS 205/250, fewer degrees and/or WSS 205/250, different degrees and/or WSS 205/250, differently arranged degrees and/or WSS 205/250, and/or different sized WSSs than those shown in fig. 2.

In an example operation of optical node 200, an input signal (e.g., an optical signal containing one or more wavelength channels) at degree D1 is received by mxn WSS 205-1 via input port 305-1. Here, if a wavelength channel of an input signal is to be dropped at a particular local drop port 325 of degree D1 (e.g., one of the set of local drop ports 325-1), the mxn WSS 205-1 may selectively route an optical signal containing the wavelength channel to the particular local drop port 325 of the set of local drop ports 325-1 (e.g., such that the wavelength channel is provided to an optical receiver associated with the particular local drop port 325).

In another example operation of the optical node 200, the M N WSS 205-1 receives an input signal at a degree D1 via input port 305-1. Here, if the wavelength channel of the input signal is to be dropped at the local drop port 325 of degree D2 (e.g., one of the set of local drop ports 325-2), the MXN WSS 250-1 can selectively route the optical signal containing the wavelength channel to a drop output 330-1, which is connected to the common input 310-2 of the MXN WSS 205-2. In this example, the mxn WSS205-2 may receive an optical signal via the common input 310-2 and route the optical signal to a particular local drop port 325 of the set of local drop ports 325-2.

In yet another example operation of the optical node 200, the M N WSS 205-1 receives an input signal at a degree D1 via input port 305-1. Here, if the wavelength channels of the input signal are to pass through the optical node 200 (i.e., are to be provided in a direction associated with the degree D2), the mxn WSS 250-1 may selectively route the optical signal containing the wavelength channels to a fast output 335-2 of the mxn WSS 205-1, which is connected to a fast input 385-2 of the mxn WSS 250-2. In this example, mxn WSS 250-2 may receive an optical signal via fast input 385-2 and route the optical signal containing the wavelength channel to output port 355-2 for output in a direction associated with degree D2.

In yet another example operation of optical node 200, an optical signal (e.g., an optical signal containing a wavelength channel) that is added at degree D1 is received by mxn WSS 250-1 via local add port 375-1 (e.g., an optical signal provided by an optical receiver connected to local add port 375-1). Here, if a wavelength channel is to be provided in the direction associated with degree D1, the mxn WSS 250-1 may selectively route an optical signal containing the wavelength channel to the output port 355-1 for output in the direction associated with degree D1.

As an additional example operation of optical node 200, mxn WSS 250-1 receives an optical signal (e.g., an optical signal containing a wavelength channel) that is added at degree D1 via local add port 375-1. Here, if the wavelength channels are to be provided in a direction associated with degree D2, then the MxN WSS 250-1 may selectively route optical signals containing the wavelength channels to a common output 360-1, which is connected to an add input 380-2 of the MxN WSS 250-2. In this example, the mxn WSS 250-2 may receive an optical signal via add input 380-2 and route the optical signal to output port 355-2 for output in a direction associated with degree D2.

When configured in the manner described herein, the optical node 200 has a so-called "east-west separability," which means that if any one of the mxn WSS 205/250 fails, the failure affects only the optical signal traveling in one direction. In this case, the affected optical signals may be routed via alternative paths (in other directions) in order to reach their intended destinations.

Example operations of the optical node 200 are provided for illustrative purposes, and other examples are possible. For example, in the case of receiving an input signal via input port 305-2, optical node 200 may operate in a manner similar to that described above. Additionally, although degrees D3 and D4 are not described in the above example operations, the optical node 200 may operate in a similar manner when routing optical signals received at the degrees D3 and/or D4 and/or provided via the degrees D3 and/or D4.

Fig. 3A and 3B are exemplary functional diagrams of an inbound mxn WSS205 and an outbound mxn WSS 250, respectively, of the optical node 200. As shown in fig. 3A, and as described above, an inbound mxn WSS205 (e.g., mxn WSS 205-1, mxn WSS 205-2) may include a set of M ports 302 (including input port 305 and a set of common inputs 310), and a set of N ports 322 (including a set of local drop ports 325 (e.g., shown connected to a corresponding set of optical Receivers (RX)), a set of drop outputs 330, and a set of express outputs 335.

As further shown in fig. 3A, the inbound mxn WSSs 205 may include one or more elements that provide the functionality of a set of M1 xn WSSs 315 (identified, for example, as 315-1 through 315-M in fig. 3A) and one or more elements that provide the functionality of a set of N optical switches 320 (identified, for example, as switches 320-1 through 320-N in fig. 3A).

The 1 × N WSS 315 contains elements capable of selectively routing optical signals received at the input of the 1 × N WSS 315, where each wavelength channel is routed independently. For example, as shown in fig. 3A, a 1 xn WSS 315-1 contains elements (e.g., via corresponding optical switches 320) capable of selectively routing optical signals received via input port 305 to any one of the set of local drop ports 325, any one of the set of drop outputs 330, and any one of the set of fast outputs 335, wherein wavelength channels are independently routed.

As another example, the 1 xn WSSs 315-2 through 315-M contain elements capable of selectively routing optical signals received via the common input 310 to any one of the set of local drop ports 325 (e.g., via the corresponding optical switch 320), where each wavelength channel is routed independently. In some embodiments, as shown in fig. 3A, the 1 × N WSSs 315-2 through 315-M need not be able to route optical signals received via their respective common inputs 310 to any one of the set of drop outputs 330 or any one of the set of fast outputs 335 (e.g., because optical signals received via the common inputs 310 contain only optical signals to be dropped at that particular inbound M × N WSS 205).

Note that while the inbound mxn WSS205 is shown as containing M separate 1 xn WSS 315, the inbound mxn WSS205 may not contain M distinct or identifiable 1 xn WSS 315. Rather, the inbound mxn WSS205 can include one or more elements that provide equivalent functionality to the M separate 1 xn WSS 315. For example, in some embodiments, the set of 1 × N WSS 315 can be implemented using different sub-regions of a Liquid Crystal On Silicon (LCOS) turning element. As another example, in some embodiments, the inbound M N WSS205 may include 1N WSS and (D-1) 1 (N-2D +2) WSS.

The optical switch 320 includes elements that enable selection of a 1 × N WSS 315 from which the optical signal is to be received through the output of the inbound mxn WSS 205. For example, as shown in FIG. 3A, the optical switch 320 associated with a given local drop port 325 may select one of 1N WSS 315-1 through 1N WSS 315-M (and provide to the given local drop port 325) from which an optical signal is to be received. As shown, each optical switch 320 is associated with a different one of the set of local drop ports 325, the set of drop outputs 330, and the set of fast outputs 335.

In some embodiments, as shown in fig. 3A, the inbound mxn WSS205 may include an optical switch 320 associated with the set of drop outputs 330 and the set of fast outputs 335 (even though the set of drop outputs 330 and the set of fast outputs 335 need only receive optical signals from the 1 xn WSS 315-1) in order to support reconfiguration of the inbound mxn WSS205 at a later time. For example, the inbound mxn WSS205 may include an optical switch 320 at each output to support reconfiguration of either the drop output 330 or the fast output 335 as the local drop port 325. Alternatively, the inbound mxn WSS may contain fewer than N optical switches.

Note that while the inbound mxn WSS205 is shown as containing N individual optical switches 320, the inbound mxn WSS205 may not contain different or identifiable optical switches 320. Rather, the inbound mxn WSS205 may contain one or more elements that provide equivalent functionality to the N optical switches. For example, in some embodiments, the set of optical switches 320 may be implemented using a micro-electromechanical systems (MEMS) mirror array, where each mirror of the MEMS array acts as an optical switch for a respective output of the inbound mxn WSS 205. In some embodiments, the inbound mxn WSS205 may include N-2D +2 optical switches 320.

As shown in fig. 3B, and as described above, an outbound mxn WSS 250 (e.g., mxn WSS 250-1, mxn WSS 250-2) may contain a set of M ports 352 (containing an output port 355 and a set of common outputs 360), and a set of N ports 372 (containing a set of local drop ports 375 (e.g., shown connected to a corresponding set of optical Transmitters (TX)), a set of add inputs 380, and a set of express inputs 385).

As further shown in fig. 3B, the outbound mxn WSS 250 may contain one or more elements that provide the functionality of a set of M1 xn WSS 365 (e.g., identified in fig. 3B as 365-1 through 365-M) and one or more elements that provide the functionality of a set of N optical switches 370 (e.g., identified in fig. 3B as switches 370-1 through 370-N).

The 1 × N WSS 365 includes elements capable of receiving an optical signal (e.g., multiple wavelength channels) at an input of the 1 × N WSS 365 and providing the optical signal via an output of the 1 × N WSS 365. For example, as shown in fig. 3B, a 1 xn WSS 365-1 contains elements capable of receiving an optical signal from any one of the set of local add ports 375, any one of the set of add inputs 380, and any one of the set of fast inputs 385 (e.g., via a corresponding optical switch 320) and providing an optical signal via an output port 355.

As another example, a 1 xn WSS 365-2 to 365-M contains elements capable of receiving an optical signal from any one of the set of local add ports 375 (e.g., via a corresponding optical switch 320) and providing the optical signal via a respective common output 360. In some embodiments, as shown in fig. 3B, the 1 x N WSS 365-2 through 365-M need not be capable of receiving optical signals from any one of the set of add inputs 380 or any one of the set of fast inputs 385 (e.g., because the optical signals received via the add inputs 380 and the fast inputs 385 only contain optical signals to be output by the degree of the outbound mxn WSS 250).

Note that while the outbound mxn WSS 250 is shown as containing M separate 1 xn WSS 365, the outbound mxn WSS 250 may not contain M distinct or identifiable 1 xn WSS 365. Rather, the outbound mxn WSS 250 may contain one or more elements that provide functionality equivalent to M separate 1 xn WSS 365. For example, in some embodiments, the set of 1 × N WSS 365 may be implemented using different sub-regions of an LCOS turning element. As another example, in some embodiments, the outbound M N WSS 250 may comprise 1N WSS and (D-1) 1 (M-2D +2) WSS.

The optical switch 370 includes elements that enable selection of a 1 × N WSS 365 to which the 1 × N WSS 365 is to be provided with an optical signal provided by an input of the outbound mxn WSS 250. For example, as shown in FIG. 3B, the optical switch 370 associated with a given local add port 375 may select one of 1N WSS 365-1 through 1N WSS 365-M to which the optical signal is to be provided. As shown, each optical switch 370 is associated with a different one of the set of local add ports 375, the set of add inputs 380, and the set of fast inputs 385.

In some embodiments, as shown in fig. 3B, the outbound mxn WSS 250 may contain an optical switch 370 associated with the set of add inputs 380 and the set of fast inputs 385 (even though the set of add inputs 380 and the set of fast inputs 385 need only provide optical signals to the 1 xn WSS 365-1) in order to support reconfiguration of the outbound mxn WSS205 at a later time. For example, the outbound mxn WSS 250 may contain an optical switch 370 at each input to support reconfiguration of the add input 380 or the fast input 385 as local add ports 375. Alternatively, the outbound mxn WSS 250 may contain fewer than N optical switches.

Note that while the outbound mxn WSS 250 is shown as containing N individual optical switches 370, the outbound mxn WSS 250 may not contain different or identifiable optical switches 370. Rather, the outbound mxn WSS 250 may contain one or more elements that provide equivalent functionality to the N optical switches. For example, in some embodiments, the set of optical switches 370 may be implemented using a MEMS mirror array, where each mirror of the MEMS array acts as an optical switch for a respective output of the outbound mxn WSS 250. In some embodiments, the outbound MXN WSS 250 may include N-2D +2 optical switches 320.

In some implementations, a given mxn WSS can act as an inbound mxn WSS205 or an outbound mxn WSS 250. In other words, the inbound mxn WSS205 and the outbound mxn WSS 250 may contain similar elements (e.g., the 1 xn WSS 315 may be the same as the 1 xn WSS 365 and the optical switch 320 may be the same as the optical switch 370), and operation as the inbound mxn WSS205 or the outbound mxn WSS 250 depends on the direction in which the optical signal is to be routed via the mxn WSS.

In some embodiments, the cost, complexity, and/or size of optical node 200 may be reduced by using an add/drop type of mxn WSS, where each of the N ports of the mxn WSS is capable of connecting to a single port of the M ports at a given time, rather than using a fully flexible and more complex wavelength cross-connect (WXC) capable of routing different wavelength optical signals from a single N port to different M ports.

The number and arrangement of elements shown in fig. 3A and 3B are provided as examples. In practice, one or more of the mxn WSS 205/250 of optical node 200 may contain additional elements, fewer elements, different elements, differently arranged elements, and/or differently sized elements than those shown in fig. 3A and 3B. Additionally, or alternatively, a set of elements (e.g., one or more elements) of the one or more mxn WSS 205/250 of the optical node 200 may perform one or more functions described as being performed by another set of elements of the one or more mxn WSS 205/250 of the optical node 200.

Fig. 4A and 4B are diagrams of example

optical nodes

400 and 425, respectively, that implement CDC add/drop using a cluster of mxn WSS 205/250 with add/drop port extensions.

Fig. 4A is a diagram of an example optical node 400 that includes add/drop port extensions. As shown in fig. 4A, the optical node 400 may include pairs of inbound and outbound mxn WSS 205/250 (e.g., including mxn WSS 205-1, mxn WSS 250-1, mxn WSS205-2, and mxn WSS 250-2), where each pair of inbound and outbound mxn WSS 205/250 is associated with a different degree (e.g., inclusion degrees D1 and D2), as described above with respect to the optical node 200.

As further shown, the optical node 400 may also include an extended inbound MXK WSS205 (K ≧ 1) (e.g., identified as MXK WSS 205-E in FIG. 4A) and/or an extended outbound MXK WSS 250 (e.g., identified as MXK 250-E in FIG. 4A). The extended inbound mxk WSS205 is a WSS that supports drop port extension of optical node 400 by providing additional local drop ports (e.g., in addition to those of inbound mxn WSS 205) that can drop optical signals. An extended egress M × K WSS 250 is a WSS that supports ingress port extension of optical node 400 by providing additional local ingress ports (e.g., in addition to those of egress M × N WSS 250) that can ingress optical signals.

In some embodiments, the M ports 302 of the extended inbound M × K WSS 205-E may contain a set of D common inputs 310-E, where each common input 310-E is connected to a downstream output 330 of the inbound M × N WSS205 associated with a degree of correspondence. For example, as shown in FIG. 4A, the first common input 310-E of the extended inbound MXK 205-E may be connected to the downstream output 330-1 of inbound MXN 205-1 associated with degree D1. As another example, the second common input 310-E of the extended inbound M × K205-E may be connected to the downstream output 330-2 of inbound M × N205-2 associated with degree D2. Although not shown, other common inputs 310-E of the extended inbound M × K WSS 205-E may be connected to the downstream outputs 330 of the inbound M × N WSS205 associated with degrees D3 and D4. In some embodiments, the set of common inputs 310-E includes D inputs.

Here, the extended inbound mxk WSS 205-E provides K additional local drop ports (e.g., identified as local drop ports 325-E) at which optical signals provided via common input 310-E may be dropped. To support drop port extensions as shown in FIG. 4A, N should be greater than or equal to 2D +1 for each inbound M N WSS205 connected to an extended inbound M K WSS 205-E.

In some embodiments, the M ports 352 of an extended outbound M K WSS 250-E may contain a set of D common outputs 360-E, where each common output 360-E is connected to an add input 380 of the outbound M N WSS 250 associated with a respective degree. For example, as shown in FIG. 4A, the first common output 360-E of the outbound MXK 250-E may be connected to the add input 380-1 of the outbound MXN 250-1 associated with degree D1. As another example, the second common output 360-E of the outbound MXK 250-E may be connected to the inbound input 380-2 of the outbound MXN 250-2 associated with degree D2. Although not shown, other common outputs 360-E of the extended outbound MXK WSS 250-E may be connected to the add inputs 380 of the outbound MXN WSS 250 associated with degrees D3 and D4. In some embodiments, the set of common outputs 360-E includes D outputs.

Here, the expansion egress mxk WSS 250-E provides K additional local add ports (e.g., identified as local add ports 375-E) at which optical signals may be added at optical node 400 and provided via common output 360. To support add port expansion as shown in FIG. 4A, N should be greater than or equal to 2D +1 for each outbound MxN WSS 250 connected to an expansion outbound MxK WSS 250-E.

Fig. 4B is a diagram of an example optical node 425 that includes cascaded layers of add/drop port extensions. As shown in fig. 4B, the optical node 425 may include pairs of inbound and outbound mxn WSS 205/250 (e.g., including mxn WSS 205-1, 250-1, 205-2, and 250-2), where each pair of inbound and outbound mxn WSS 205/250 is associated with a different degree (e.g., including degrees D1 and D2), as described above with respect to the optical node 200.

As further shown, the optical node 425 may also contain a layer of extensions M N WSS 205/250 (identified in FIG. 4B as M N WSS 205-E1, 250-E1, 205-E2, and 250-E2, for example). Here, each degree of the optical node 425 may have an associated extended inbound mxn WSS205 and an associated extended outbound mxn WSS 250. The extended ingress/egress mxn WSS 205/250 supports ingress/egress port extension of optical node 425 by providing additional local ingress/egress ports (e.g., in addition to those of mxn WSS 205-1, 250-1, 205-2, and 250-2) that can ingress/egress optical signals.

In some embodiments, the downstream output 330 of the inbound mxn WSS205 is connected to the input port 305 of the extended inbound mxn WSS 205. For example, as shown in FIG. 4B, the downstream output 330-1 of the inbound M N WSS 205-1 may be connected to the input ports 305-E1 of the extended inbound M N205-E1 associated with degree D1. As another example, the downstream output 330-2 of the inbound M N WSS205-2 may be connected to the input ports 305-E2 of the extended inbound M N205-E2 associated with degree D2. Although not shown, the downstream output 330 of the inbound mxn WSS205 associated with the degrees D3 and D4 may similarly be connected to the input port 305 of the extended inbound mxn WSS205 associated with the degrees D3 and D4.

In some embodiments, the add input 380 of the outbound mxn WSS 250 is connected to the output port 355 of the extended outbound mxn WSS 250. For example, as shown in FIG. 4B, the add input 380-1 of the outbound MXN WSS 250-1 may be connected to the output ports 355-E1 of the extended outbound MXN 250-E1 associated with degree D1. As another example, the add input 380-2 of the outbound MXN WSS 250-2 may be connected to the output port 355-E2 of the expanded outbound MXN 250-E2 associated with degree D2. Although not shown, the add inputs 380 of the outbound mxn WSSs 250 associated with the degrees D3 and D4 may similarly be connected to the output ports 355 of the extended outbound mxn WSSs 250 associated with the degrees D3 and D4.

As further shown in FIG. 4B, the connections between the M N WSS 205-E1, 250-E1, 205-E2, and 250-E2 may be similar to the connections between the M N WSS 205-1, 250-1, 205-2, and 250-2, as described above with respect to FIG. 2. To support drop port expansion as shown in FIG. 4B, N should be greater than or equal to 2D +1 for each M N WSS 205/250.

At optical node 425, the extended inbound M × N WSS 205-E1 provides N-2D +1 additional local drop ports (e.g., identified as local drop ports 325-E1) via which optical signals may be dropped at degree D1, and the extended inbound M × N WSS 205-E2 provides N-2D +1 additional local drop ports (e.g., identified as local drop ports 325-E2) via which optical signals may be dropped at degree D2. Similarly, the outbound M N WSS 250-E1 provides N-2D +1 additional local add ports (e.g., identified as local add ports 375-E1) via which optical signals may be added at degree D1, and the outbound M N WSS 250-E2 provides N-2D +1 additional local add ports (e.g., identified as local add ports 375-E2) via which optical signals may be added at degree D2. Although not shown, the extended inbound mxn WSS205 and the extended outbound mxn WSS 250 associated with degrees D3 and D4 may provide similar add/drop extensions.

As shown in fig. 4B, additional extension inbound/extension outbound mxn WSSs 205/250 may be added to the optical node 425 (e.g., by connecting the drop output 330 of the extension inbound mxn WSS205 to the input port 305 of the additional extension inbound mxn WSS205, by connecting the add input 380 of the extension outbound mxn WSS 250 to the output port 355 of the additional extension outbound mxn WSS 250, etc.). By cascading layers of the mxn WSS 205/250, the optical node 425 can support infinite add/drop port extensions.

The number and arrangement of elements shown in fig. 4A and 4B are provided as examples. In practice, the optical nodes 400 and/or 425 may contain additional degrees and/or WSS 205/250, fewer degrees and/or WSS 205/250, different degrees and/or WSS 205/250, differently arranged degrees and/or WSS 205/250, and/or different sized WSSs than those shown in fig. 4A and 4B.

The above-described embodiments provide an architecture for implementing CDC add/drop optical nodes with a single-layer component, i.e., a single M N WSS (M ≧ D, N ≧ 2D) connected to each inbound fiber and each outbound fiber. Optical nodes implementing the CDC using single layer components have reduced cost, complexity, and/or physical size compared to prior art optical nodes implementing the CDC add/drop.

In the above embodiments, degree expansion (scaling) may be achieved by including an mxn WSS 205/250 with additional ports. For example, to support 4 degrees of 10 add/drop ports per degree (D ═ 4), 4 × 16 WSS 205/250 would be needed at optical node 200. Similarly, 8 × 24WSS 205/250 would be required to support 8 degrees of 10 add/drop ports per degree (D ═ 8), and 16 × 40 WSS 205/250 would be required to support 16 degrees of 10 add/drop ports per degree (D ═ 16).

As network capacity increases, the number of degrees to be supported at a given optical node may also increase, and thus, a given optical node may require more than 16 degrees of connectivity in order to support capacity growth. Supporting an expanding optical node 200 beyond 16 degrees may require the development of an mxn WSS 205/250 with M and N number of ports sufficient to support the required application (e.g., an mxn WSS where M >16, such as M ═ 32, and where N is greater than 40). However, such devices may be undesirably expensive, complex, and/or difficult to develop. Furthermore, expanding the optical node 200 in the manner described above would require replacing the relatively small M × N WSS of the optical node 200 with a relatively large M × N WSS, and the cost of doing so may be high.

Thus, in some embodiments, an optical node may be configured to implement CDC add/drop using an M × N WSS 205/250 while supporting expansion beyond M degrees. For example, the M N WSS 205/250 may be configured to support M-2 degrees without degree extension, 2 × (M-2) degrees by extension to a second configuration, 3 × (M-2) degrees by extension to a third configuration, and so on. As a particular example, an 8 x 24WSS 205/250 (e.g., each dual 8 x 24WSS 205/250, containing inbound 8 x 24 WSSs 205 and outbound 8 x 24 WSSs 250, which are optically independent WSSs arranged in the same physical space and possibly sharing certain optical components) may be configured to support 6(8-2 ═ 6) degrees without degree expansion, up to 12(2 × (8-2) ═ 12) degrees by expansion to a second configuration, up to 18(3 × (8-2) ═ 18) degrees by expansion to a third configuration, and so on.

Fig. 5-7 are diagrams associated with an example optical node 500, the example optical node 500 configured to implement CDC add/drop using an M × N WSS 205/250 while supporting expansion beyond M degrees. In FIG. 5, dual M N WSS 205/250 (identified as dual 8X 24WSS) are shown, where a given dual M N WSS 205/250 contains an inbound M N WSS205 and an outbound M N WSS 250. Note that while the dual mxn WSS 205/250 is shown in the optical node 500, the embodiments described below may be used in optical nodes that contain dispersed inbound mxn WSSs 205 and outbound mxn WSSs 250. Further, while the dual mxn WSS 205/250 shown in the example optical node 500 is shown as having a particular port configuration and number (e.g., M-8 and N-24), the port configuration and/or number of the dual mxn WSS 205/250 may be greater than or less than the port number shown in fig. 5 (i.e., M may be greater than or less than 8 and/or N may be greater than or less than 24).

To support expansion beyond M degrees, a subset of the dual M × N WSS 205/250 of the optical node 500 is configured as degree extensions, each degree extension containing a dual extension M × N WSS 205/250. Here, a given dual M N WSS 205/250 includes an inbound extension M N WSS205 and an outbound extension M N WSS 250. In some embodiments, as described below, a degree extension of the optical node 500 (e.g., the dual extension mxn WSS 205/250 or the inbound extension mxn WSS 250 and the outbound extension mxn WSS 250) may be connected to another degree extension in association with increasing the number of degrees supported by the optical node 500.

As an example, in the optical node 500, a set of six dual M × N WSS 205/250 (e.g., the six unshaded dual 8 × 24WSS in fig. 5) are respectively associated with respective degrees (e.g., D1 through D6), while a set of two dual M × N WSS205 (e.g., the two shaded dual 8 × 24WSS in fig. 5) are configured as degree extensions, each degree extension containing a dual extension M × N WSS 205/205. In this example, each of the set of six dual M × N WSS 205/250 supports a respective degree, while each of the set of two extensions M × N WSS 205/250 may be connected to a degree extension configured in another other M × N WSS. Note that this concept can be used to extend the support of optical nodes that contain 16 x N WSS (e.g., where N >30) to more than 16 degrees.

An example of an optical node 500 that is extended to support degrees of add is shown in fig. 6. As shown in fig. 6, another configuration of six dual M × N WSSs 205/250 (e.g., the six unshaded dual 8 × 24 WSSs in the right half of fig. 6) is respectively associated with respective add-on degrees (e.g., D7 through D12), while each of the other set of two dual M × N WSSs 205 (e.g., the two shaded dual 8 × 24 WSSs in the right half of fig. 6) is configured as a degree extension. In this example, two configurations of the dual mxn WSS 205/250 (e.g., left and right, collectively) support 12 degrees (e.g., D1 through D12). Support for 12 degrees is provided by connecting the degree extension E2 of the first configuration of M × N WSSs (e.g., the right double extension M × N WSS 205/250 in the first configuration of optical node 500) to the degree extension E3 of the second configuration of M × N WSSs (e.g., the left double extension M × N WSS 205/250 in the second configuration of M × N WSSs). Additional degree support may be provided in a similar manner by connecting degree extensions E1 and/or E4 to other configurations of the mxn WSS 205/250 in a similar manner.

In general, as shown in FIG. 6, an optical node 500 may have a group configuration that supports D (D ≧ 1) degrees, where each degree includes an inbound MXN WSS205 and an outbound MXN WSS 250 (or dual MXN WSS 205/250). The degree support is provided by E (E ≧ 1) degree extensions, where each degree extension contains an inbound extension M × N WSS205 and an outbound extension M × N WSS 250 (or a dual extension M × N WSS 205/250).

In operation, a signal of an inbound mxn WSS205 input (e.g., via input port 305) to a given one of the D degrees of the configuration of optical node 500 may be routed to any drop port 325 or any degree in any configuration of optical node 500. For example, a signal input to the input port 305 associated with degree D1 may be routed to any drop port 325 of degrees D1 through D6 of the first configuration of the optical node, any drop port 325 of degrees E1 or E2 of the first configuration of the optical node 500, any drop port 325 of degrees D7 through D12 of the second configuration of the optical node 500 (e.g., via degree extensions E2 and E3), or any drop port 325 of degrees E3 and E4 of the second configuration of the optical node 500 (e.g., via degree extensions E2 and E3). As another example, a signal input to the input port 305 associated with degree D12 may be routed to any drop port 325 of the second configured degrees D7 through D12 of the optical node 500, any drop port 325 of the second configured degree expansion E3 or E4 of the optical node 500, any drop port 325 of the first configured degrees D1 through D6 of the optical node 500 (e.g., via degree expansions E3 and E2), or any drop port 325 of the first configured degree expansions E1 and E2 of the optical node 500 (e.g., via degree expansions E3 and E2).

Further, in operation, signals input (e.g., via add port 375) to an outbound mxn WSS 250 of a given one of the D degrees of the configuration of optical node 500 may be routed to any outbound mxn WSS 250 of any degree in any configuration of optical node 500. For example, a signal input to the add port 375 associated with degree D6 may be routed to any outbound mxn WSS 250 of degrees D1 through D5 of the first configuration of optical nodes or any outbound mxn WSS 250 of degrees D7 through D12 of the second configuration of optical nodes 500 (e.g., via degree extensions E2 and E3). As another example, a signal input to the add port 375 associated with degree D7 may be routed to any outbound mxn WSS 250 of degrees D8 through D12 of the second configuration of optical node 500, or any outbound mxn WSS 250 of degrees D1 through D6 of the first configuration of optical node 500 (e.g., via degree extensions E3 and E2).

Note that although fig. 6 shows that degree extension E2 of the first configuration (left configuration) is connected to receive and provide signals to degree extension E3 of the second configuration (right configuration), different configurations of connection are possible in some cases. For example, the degree extension E2 may be connected to receive signals from the degree extension E3, but the degree extension E2 may also be connected such that the degree extension E2 sends signals to the degree extension E5 of the third configuration of the optical node 500 (not shown). In this case, an optical path may be provided (e.g., via the third configuration) for providing these signals to the second configuration of the optical node 500.

Fig. 7 is a diagram showing the connections of a given configuration of an optical node 500 that supports the above-described operations. The connections of the M × N WSS 205/250 (identified in fig. 7 as unshaded double M × N) are similar to those described above in connection with fig. 2, and the connections of the extended M × N WSS 205/250 (identified in fig. 7 as shaded double M × N) are described below.

As described above, the dual extension mxn WSS 205/250 may include the inbound extension mxn WSS205 and the outbound extension mxn WSS 250. In fig. 7, connections associated with the inbound mxn WSS205 are shown by solid lines, while connections associated with the outbound mxn WSS 250 are shown by dashed lines. In some embodiments, as shown in FIG. 7, the inbound extension M N WSS205 may include an extension input 505, a set of Common Inputs (CI)310 (e.g., M1 common inputs), a set of local drop ports 325 (e.g., N- (2 x (M-1)) local drop ports), a set of Drop Outputs (DO)330 (e.g., M1 drop outputs), and a set of fast outputs (EO)335 (e.g., M1 fast outputs).

The extension input 505 is a port of the inbound extension mxn WSS205 via which the inbound extension mxn WSS205 may receive optical signals from the outbound extension mxn WSS 250 associated with another configuration of the optical node 500. In some embodiments, one of the M ports 302 (as identified in fig. 3A) of the inbound extension mxn WSS205 is configured as an extension input 505. In some embodiments, the extension input 505 of the inbound extension mxn WSS205 is configured such that an optical signal may be routed from the extension input 505 to any local drop port 325 of the inbound extension mxn WSS205, to any drop output 330 of the inbound mxn WSS205 (e.g., when the optical signal is to be dropped at a local drop port 325 of another inbound mxn WSS 205), or to any express output 335 of the inbound extension mxn WSS205 (e.g., when the optical signal is to be provided via another degree of configuration of the optical node 500). The connections supporting such routing may be similar to those described above in connection with fig. 2 and 3A.

In some implementations, the extension input 505 is connected to an extension output 555 of the outbound extension mxn WSS 250 included in another configured degree extension of the optical node 500 (e.g., such that the inbound extension mxn WSS205 can receive signals from another configured extended outbound mxn WSS 250). This connection is shown in fig. 6 as a connection between the left configured degree extension E2 of the optical node 500 and the right configured extension E3 of the optical node 500. More specifically, the extension input 505 of the left configured inbound extension mxn WSS205 of the optical node 500 may be connected to the extension output 555 of the right configured outbound extension mxn WSS 250 of the optical node 500. Similarly, the extension input 505 of the right configured inbound extension mxn WSS205 of the optical node 500 may be connected to the extension output 555 of the left configured outbound extension mxn WSS 250 of the optical node 500. In some embodiments, as shown in fig. 6, optical amplifiers may be arranged between differently configured degree extensions of the optical node 500 (e.g., between the extension inputs 505 and associated extension outputs 555) to allow for appropriate power levels for maintaining fast traffic and add/drop traffic when transmitting between degree extensions of the optical node 500.

In some embodiments, the degree extension E of the optical node 500 allows any inbound mxn WSS205 signal of a given degree input into the first configuration of the optical node 500 to be routed to any drop port in the second configuration of the optical node 500. Additionally, the degree extension E of the optical node 500 may allow any inbound mxn WSS205 signal of a given degree input into the second configuration of the optical node 500 to be routed to any drop port in the first configuration of the optical node 500.

Returning to fig. 7, in some embodiments, an inbound extension mxn WSS205 of a given degree extension E may include a group of common inputs 310, each of a first set of the group of common inputs 310 connected (via a fiber shuffle (shuffle)) to a respective drop output 330 of the inbound mxn WSS205 of a configured degree of the optical node 500 (e.g., in a manner similar to that described in connection with fig. 2). In some embodiments, each of the second set of the group of common inputs 310 is connected to a respective drop output 330 of another degree of extension of the inbound extension mxn WSS205 of the configuration of the optical node 500. For example, the inbound extension mxn WSS205 of degree extension E2 may contain a cluster of seven common inputs 310, with a set of six inputs of the seven common inputs 310 each connected to a respective drop output 330 of the six inbound mxn WSS205 of degrees D1 through D6, and the seventh common input 310 connected to the drop output 330 of the inbound extension mxn WSS205 of degree extension E1.

In some implementations, the inbound extension mxn WSS205 can contain a group of fast outputs 335, each of a first set of the group of fast outputs 335 connected (via fiber shuffling) to a respective one of a set of fast inputs 385 of the outbound mxn WSS 250 for a configured degree of the optical node 500 (e.g., in a manner similar to that described in connection with fig. 2). In some embodiments, each of the second set of the group fast outputs 335 is connected to a respective fast input 385 of the outbound extension mxn WSS 250 of another degree of extension of the configuration of the optical node 500. For example, the inbound extension mxn WSS205 of degree extension E2 may contain a cluster of seven fast outputs 335, where each of a set of six outputs of the seven fast outputs 335 is connected to a respective fast input 385 of six outbound mxn WSS 250 of degrees D1 through D6, and the seventh fast output 335 is connected to the fast input 385 of the outbound extension mxn WSS 250 of degree extension E1.

In some embodiments, the inbound extension mxn WSS205 may contain a group of drop outputs 330, each of a first set of the group of drop outputs 330 connected (via the fiber shuffle) to a respective one of a set of common inputs 310 of the inbound mxn WSS205 for a configured degree of the optical node 500 (e.g., in a manner similar to that described in connection with fig. 2). In some embodiments, each of the second set of the group of drop outputs 330 is connected to a respective common input 310 of another degree of extension of the inbound extension mxn WSS205 of the configuration of the optical node 500. For example, the inbound extension mxn WSS205 of degree extension E2 may contain a cluster of seven drop outputs 330, where a set of six inputs of the seven common inputs 310 are each connected to a respective common input 310 of the six inbound mxn WSS205 of degrees D1 through D6, and the seventh drop output 330 is connected to the common input 310 of the inbound extension mxn 205 of degree extension E2.

In some embodiments, the inbound extension mxn WSS205 may include a set of local drop ports 325 (e.g., in a manner similar to that described in connection with fig. 2). Thus, in some embodiments, the inbound extension mxn WSS205 may be configured to allow for the drop of signals via the local drop port 325 of the inbound extension mxn WSS205 (e.g., additionally supporting dropping to a given degree of the local drop port 325).

With respect to the outbound extension M N WSS 250, as shown in FIG. 7, the outbound extension M N WSS205 may include an extension output 555, a set of Common Outputs (CO)360 (e.g., M-1 common outputs), a set of local add ports 375 (e.g., N- [ 2X (M-1) ] local add ports), a set of Add Inputs (AI)380 (e.g., M-1 add inputs), and a set of Express Inputs (EI)385 (e.g., M-1 express inputs).

The extension output 555 is a port of the outbound extension mxn WSS 250 via which the outbound extension mxn WSS 250 may provide an optical signal to the inbound extension mxn WSS205 associated with another configuration of the optical node 500. In some embodiments, one of the M ports 302 (as identified in fig. 3A) of the outbound extension mxn WSS 250 is configured as an extension output 555. In some embodiments, the extension outputs 555 of the outbound extension mxn WSS 250 are configured such that optical signals can be routed from any local add port 375 of the outbound extension mxn WSS 250 to the extension outputs 555, from any add input 380 of the outbound extension mxn WSS 250 to the extension outputs 555, or from any fast input 385 of the outbound extension mxn WSS 250 to the extension outputs 555. The connections supporting such routing may be similar to those described above in connection with fig. 2 and 3B.

In some implementations, an outbound extension mxn WSS 250 of a given degree extension E may contain a group of common outputs 360, each of a first set of the group of common outputs 360 connected (via the optical fiber shuffle) to a respective inbound input 380 of the outbound mxn WSS 250 of a configured degree of the optical node 500 (e.g., in a manner similar to that described in connection with fig. 2). In some embodiments, each of the second set of the group common outputs 360 is connected to a respective add input 380 of the outbound extension mxn WSS 250 of the other degree extension of the configuration of the optical node 500. For example, the outbound extension M × N WSS 250 of the degree extension E2 may contain a cluster of seven common outputs 360, with a set of six outputs of the seven common outputs 360 each connected to a respective inbound input 380 of six outbound M × N WSS 250 of the degrees D1 through D6, and the seventh common output 360 connected to the inbound input 380 of the outbound extension M × N WSS 250 of the degree extension E1.

In some embodiments, the outbound extension mxn WSS 250 may include a group of fast inputs 385, each of a first set of the group of fast inputs 385 connected to a respective fast output 335 of the inbound mxn WSS205 of a configured degree of the optical node 500 (e.g., in a manner similar to that described in connection with fig. 2). In some embodiments, each of the second set of the set of fast inputs 385 is connected to a respective fast output 335 of the another degree extended inbound extension mxn WSS205 of the configuration of the optical node 500. For example, the outbound extension M × N WSS 250 of degree extension E2 may contain a set of seven fast inputs 385, with each of the set of six inputs of the seven fast inputs 385 connected to a respective fast output 335 of six inbound M × N WSS205 of degrees D1 through D6, and the seventh fast input 385 connected to the fast output 335 of the inbound extension M × N WSS205 of degree extension E1.

In some embodiments, the outbound extension mxn WSS 250 may include a group of inbound inputs 380, each of a first set of the group of inbound inputs 380 connected to a respective common output 360 of the outbound mxn WSS 250 of the configured degree of the optical node 500 (e.g., in a manner similar to that described in connection with fig. 2). In some embodiments, each of the second set of the group add-ins 380 is connected to a respective common output 360 of the other degree extended outbound extension mxn WSS 250 of the configuration of the optical node 500. For example, the outbound extension M × N WSS 250 degrees of extension E2 may contain a cluster of seven inbound inputs 380, where a set of six inputs of the seven inbound inputs 380 are each connected to a respective common output 360 of six outbound M × N WSS205 of degrees D1 through D6, and the seventh inbound input 380 is connected to the common output 360 of the outbound extension M × N WSS205 of degree extension E1.

In some embodiments, the outbound extension mxn WSS 250 may include a set of local add ports 375 (e.g., in a manner similar to that described in connection with fig. 2). Thus, in some embodiments, the outbound extension mxn WSS 250 may be configured to allow signals to be uplinked via the local add port 375 of the outbound extension mxn WSS 250 (e.g., in addition to the local add port 375 of a given degree).

The number and arrangement of elements shown in fig. 5-7 are provided as examples. In practice, the optical node 500 may contain additional degrees and/or WSS 205/250, fewer degrees and/or WSS 205/250, different degrees and/or WSS 205/250, differently arranged degrees and/or WSS 205/250, and/or different sized WSSs than those shown in fig. 5-7.

The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of the embodiments.

Although particular combinations of features are set forth in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of possible embodiments. Indeed, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. Although each dependent claim listed below may refer directly to only one claim, the disclosure of possible embodiments encompasses each dependent claim in combination with every other claim in the set of claims.

No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. In addition, as used herein, the articles "a" and "an" are intended to include one or more items, and may be used interchangeably with "one or more". Further, as used herein, the term "group" is intended to encompass one or more items (e.g., related items, unrelated items, combinations of related and unrelated items, etc.), and may be used interchangeably with "one or more. Where there is only one item, the term "one" or similar language is used. Further, as used herein, the terms "having," "with," and the like are intended to be open-ended terms. Further, the phrase "based on" is intended to mean "based, at least in part, on" unless explicitly stated otherwise.

Claims

1. An optical node, comprising:

an arrangement, comprising:

d degrees, wherein D ≧ 1, each of the D degrees including an inbound Wavelength Selective Switch (WSS) and an outbound WSS; and

e degree extensions, wherein E is more than or equal to 1, each degree extension in the E degree extensions comprises an inbound extension WSS and an outbound extension WSS,

wherein the inbound extension WSS included in the degree extension of the E degree extension includes:

an extension input connected to an extension output of an outbound extension WSS, the outbound extension WSS included in a degree extension of a first other configuration of the optical node,

d common inputs connected to D drop outputs, each drop output at a respective inbound WSS of D degrees,

d fast outputs connected to D fast inputs, each fast input at a respective outbound WSS of D degrees,

d drop outputs connected to D common inputs, each common input at a respective inbound WSS of D degrees, an

At least one local drop port for the local drop,

wherein the outbound extension WSS included in the degree extension of the E degree extension includes:

an extension output connected to an extension input of an inbound extension WSS, the inbound extension WSS included in a degree extension of a second other configuration of the optical node,

d common outputs connected to D add inputs, each add input at a respective outbound WSS of D degrees,

d fast inputs connected to D fast outputs, each fast output at a respective inbound WSS of D degrees,

d add inputs connected to D common outputs, each common output at a respective outbound WSS of D degrees, an

At least one of the local upstream ports is,

wherein a signal input to a given one of the D degrees of the inbound WSS can be routed to any drop port included in the second other configuration of optical nodes via one of the E degree extensions;

wherein a signal input to any add port included in the first other configuration can be routed to an outbound WSS of any one of the D degrees via a degree extension of the E degree extensions;

wherein the first further configuration of the optical node and the second further configuration of the optical node are the same configuration of the optical node.

2. The optical node of claim 1 wherein the inbound extension WSS and the outbound extension WSS associated with one of the E degree extensions are optically independent WSSs arranged in the same physical space.

3. The optical node of claim 1 wherein:

the inbound extension WSS included in the degree extension of the E degree extension further includes:

a common input connected to a drop output of another degree of extension of the E degree extension,

a fast output connected to the fast input of the other degree extension of the E degree extension, an

A drop output connected to a common input of the other degree of extension of the E degree extension; and the outbound extension WSS included in the degree extension of the E degree extension further includes:

a common output connected to the add inputs of other ones of the E degree extensions,

a fast input connected to the fast output of the other degree extension of the E degree extension, an

An add input connected to a common output of the other degree extensions of the E degree extension.

4. The optical node of claim 1 wherein the inbound WSS and the outbound WSS associated with one of the D degrees are optically independent WSSs arranged in the same physical space.

5. The optical node of claim 1 wherein the number of D degrees is at least 6, i.e., D ≧ 6.

6. The optical node of claim 1 wherein the number of E degree extensions is at least 2, i.e., E ≧ 2.

7. An optical node, comprising:

a first configuration comprising:

d1 degrees, wherein D1 ≧ 1, each of the D1 degrees comprising an inbound Wavelength Selective Switch (WSS) and an outbound WSS; and

a first degree extension comprising a first inbound extension WSS and a first outbound extension WSS,

wherein the first inbound extension WSS includes an extension input connected to an extension output of a second outbound extension WSS included in a second degree extension of the second configuration, and

wherein the first outbound extension WSS includes an extension output connected to an extension input of a second inbound extension WSS included in a second degree extension of the second configuration; and

a second configuration comprising:

d2 degrees, wherein D2 is more than or equal to 1, and each degree of D2 degrees comprises an inbound WSS and an outbound WSS;

a second degree extension comprising a second extension inbound WSS and a second extension outbound WSS,

wherein the second inbound extension WSS includes an extension input connected to the extension output of the first outbound extension WSS,

wherein the second outbound extension WSS includes an extension output connected to the extension input of the first inbound extension WSS,

wherein a signal input to the inbound WSS of a given one of the D1 degrees can be routed to any drop port included in the second configuration via the first degree extension and the second degree extension, and

wherein a signal input to a given one of the D2 degrees of the inbound WSS can be routed to any drop port included in the first configuration via the second degree extension and the first degree extension.

8. The optical node of claim 7 wherein signals input to any add port included in the first configuration can be routed to an outbound WSS of any one of D2 degrees via a first degree of spreading and a second degree of spreading.

9. The optical node of claim 7 wherein signals input to any add port included in the second configuration can be routed to an outbound WSS of any of D1 degrees via the second degree of expansion and the first degree of expansion.

10. The optical node of claim 7 wherein the first inbound extension WSS and the first outbound extension WSS are optically independent WSSs arranged in the same physical space.

11. The optical node of claim 7 wherein the second inbound extension WSS and the second outbound extension WSS are optically independent WSS arranged in the same physical space.

12. The optical node of claim 7, wherein the first configuration further comprises:

a third degree extension comprising a third inbound extension WSS and a third outbound extension WSS,

wherein the third inbound extension WSS includes an extension input connected to an extension output of a fourth outbound extension WSS included in a fourth degree extension of the third configuration, and

wherein the third outbound extension WSS includes an extension output connected to an extension input of a fourth inbound extension WSS included in a fourth degree extension of the third configuration.

13. The optical node of claim 7 wherein the number of D1 degrees is at least 6, i.e., D1 ≧ 6.

14. The optical node of claim 7 wherein the number of D2 degrees is at least 6, i.e., D2 ≧ 6.

15. An optical node, comprising:

a first configuration comprising:

a set of degrees, each degree comprising an inbound Wavelength Selective Switch (WSS) and an outbound WSS; and

wherein an extension input of the first inbound extension WSS is connected to an extension output of a second outbound extension WSS included in a second degree extension of the second configuration of the optical node, and

wherein an extension output of the first outbound extension WSS is connected to an extension input of a second inbound extension WSS included in a second degree extension of the second configuration,

wherein a signal input to the inbound WSS of a given one of the set of degrees can be routed to any drop port included in the second configuration via the first degree extension and the second degree extension, and

wherein signals input to a given one of the other sets of degrees can be routed to any drop port included in the first configuration via the second degree extension and the first degree extension.

16. The optical node of claim 15 wherein the second configuration comprises:

another set of degrees, each degree comprising an inbound WSS and an outbound WSS; and

wherein the extension input of the second inbound extension WSS is connected to the extension output of the first outbound extension WSS,

wherein the extension output of the second outbound extension WSS is connected to the extension input of the first inbound extension WSS.

17. The optical node of claim 16 wherein signals input to any add port included in the first configuration can be routed to an outbound WSS of any one of the other group degrees via the first degree extension and the second degree extension.

18. The optical node of claim 15 wherein signals input to any add port included in the second configuration can be routed to the outbound WSS of any one of the set of degrees via the second degree extension and the first degree extension.