The present disclosure generally relates to optical networking. More particularly, the present disclosure relates to systems and methods for integrated band splitter for scaling a dual-band Reconfigurable Optical Add/Drop Multiplexer (ROADM).
Optical networks utilize Reconfigurable Optical Add-Drop Multiplexers (ROADMs) to realize selective and reconfigurable add/drop of wavelengths or spectrum locally and between various degrees. ROADMs generally utilize Wavelength Selective Switches (WSSs) in different configurations. A ROADM is a key building block forming a terminal where there is local add/drop of optical channels and where there is routing of optical channels between multiple degrees. The optical channels are located on optical spectrum that typically includes the C-band (˜1530 nm-1565 nm) and the L-band (˜1565 nm-1625 nm). Initial deployments were confined to the C-band only. As capacity has increased, so have optical networks to include both C-band and the L-band. Conventional deployments of an optical networking system utilizing the C-band and the L-band utilize separate equipment components. That is, there is typically a splitter/combiner and parallel sets of equipment for the C-band and for the L-band. While this approach scales capacity on the optical fiber, it requires 2× equipment. As C+L band systems become common, there is a drive towards integrated equipment to reduce the duplication of equipment. While this reduces the amount of equipment required, there is a trade-off in terms of add/drop capacity in a ROADM. For example, integrating C+L band equipment in degree components (e.g., a Wavelength Selective Switch (WSS)) in a ROADM reduces the amount of local add/drop at the ROADM.
To support integrated C+L band equipment in a ROADM, there is a need to address the local add/drop scalability.
The present disclosure relates to systems and methods for integrated band splitter for scaling a dual-band Reconfigurable Optical Add/Drop Multiplexer (ROADM). The present disclosure addresses port scalability in integrated C+L band equipment through a band splitter in between the ROADM components and the channel multiplexer/demultiplexer components. With the use of the band splitter, any port can be either C+L band thereby recovering ports. As noted above, integrated C+L band equipment causes a reduction in the number of ports.
In an embodiment, a degree in a Reconfigurable Optical Add/Drop Multiplexer (ROADM) includes ROADM components including a line port and a plurality of connection ports; channel multiplexer/demultiplexer components including degree ports and local add/drop ports; and one or more band splitters in between the ROADM components and the channel multiplexer/demultiplexer components. The ROADM components can include integrated C-band and L-band functionality. The ROADM components can include integrated C-band and L-band functionality and the channel multiplexer/demultiplexer components are separate for the C-band and L-band functionality. The ROADM components can include a Wavelength Selective Switches (WSS) that supports integrated C-band and L-band functionality.
Each of the one or more band splitters can include three ports with a common port configured to connect to one of the plurality of connection ports, a C-band port configured to connect to a degree port of C-band channel multiplexer/demultiplexer components, and an L-band port configured to connect to a degree port of L-band channel multiplexer/demultiplexer components. The band splitter can be configured to split/combine C-band spectrum and L-band spectrum. The band splitter can be a passive fiber device. The band splitter can be integrated into a fiber shuffler located between the ROADM components and the channel multiplexer/demultiplexer components.
In another embodiment, a Reconfigurable Optical Add/Drop Multiplexer (ROADM) node includes one or more degrees configured to connect to optical fibers in an optical network, each of the one or more degrees include ROADM components including a line port and a plurality of connection ports; channel multiplexer/demultiplexer components including degree ports and local add/drop ports; and one or more band splitters in between the ROADM components and the channel multiplexer/demultiplexer components. The ROADM components can include integrated C-band and L-band functionality. The ROADM components can include integrated C-band and L-band functionality and the channel multiplexer/demultiplexer components are separate for the C-band and L-band functionality.
The ROADM components can include a Wavelength Selective Switches (WSS) that supports integrated C-band and L-band functionality. Each of the one or more band splitters can include three ports with a common port configured to connect to one of the plurality of connection ports, a C-band port configured to connect to a degree port of C-band channel multiplexer/demultiplexer components, and an L-band port configured to connect to a degree port of L-band channel multiplexer/demultiplexer components. The band splitter can be configured to split/combine C-band spectrum and L-band spectrum. The band splitter can be a passive fiber device. The band splitter can be integrated into a fiber shuffler located between the ROADM components and the channel multiplexer/demultiplexer components. Degree-to-degree connectivity can be via connections between the connection ports of the respective degrees.
In a further embodiment, a method includes providing ROADM components including a line port and a plurality of connection ports for connectivity to an optical network; providing channel multiplexer/demultiplexer components including degree ports and local add/drop ports for local add/drop; and utilizing one or more band splitters in between the ROADM components and the channel multiplexer/demultiplexer components for scaling add/drop connectivity to the ROADM components. The ROADM components can include integrated C-band and L-band functionality and the channel multiplexer/demultiplexer components are separate for the C-band and L-band functionality. Each of the one or more band splitters can include three ports with a common port configured to connect to one of the plurality of connection ports, a C-band port configured to connect to a degree port of C-band channel multiplexer/demultiplexer components, and an L-band port configured to connect to a degree port of L-band channel multiplexer/demultiplexer components.
The present disclosure is illustrated and described herein with reference to the various drawings, in which like reference numbers are used to denote like system components/method steps, as appropriate, and in which:
The present disclosure relates to systems and methods for integrated band splitter for scaling a dual-band Reconfigurable Optical Add/Drop Multiplexer (ROADM). The present disclosure addresses port scalability in integrated C+L band equipment through a band splitter in between the ROADM components and the channel multiplexer/demultiplexer components. With the use of the band splitter, any port can be either C+L band thereby recovering ports. As noted above, integrated C+L band equipment causes a reduction in the number of ports.
As is known in the art, a ROADM degree 10 includes various components for interfacing optical fibers at a terminal. Each network element can have one to N degrees, N being an integer. For example, a one-degree node interfaces a single adjacent node. A two-degree node interfaces two adjacent nodes, e.g., a logical East and West direction, a four-degree node interfaces four adjacent nodes, e.g., a logical North, South, East, and West direction, etc. ROADM deployments are scaling, and it is possible to have multiple degree nodes, including 16 degrees are more.
The present disclosure relates to a ROADM architecture for dual-band operation. Note, traditionally, the most used bands in the optical spectrum are the C-band (˜1530 nm-1565 nm) and the L-band (˜1565 nm-1625 nm). Of course, there can be other bands as are known in the art. The ROADM degrees 10 in all of the
Functionally, the ROADM degree 10 includes a line side 12 and a local add/drop side 14 with intervening components therebetween. The ROADM degree 10 in
The ROADM modules 20 interfaces the line side 12 and can include, e.g., twin 1×32 flexible grid WSSs (one for transmit and one for receive), pre- and post-amplifiers such as Erbium-Doped Fiber Amplifiers (EDFAs), bi-directional Optical Time Domain Reflectometer (OTDR), Optical Channel Monitors (OCMs), Optical Service Channels (OSC), integrated Amplified Spontaneous Emission (ASE) sources for channel loading, and the like. The ROADM module 20 is referenced as a ROADM module 20C, 20L, 20CL where the suffix C, L, and CL denote the components support the C-band, the L-band, and both the C-band and the L-band in an integrated manner, respectively.
The channel multiplexer/demultiplexer modules 22 interfaces the local add/drop side 14 connecting to local optical modems, transceivers, transponders, etc. The channel multiplexer/demultiplexer modules 22 also can include contentionless WSSs for interconnecting local add/drop channels to any degree (i.e., ROADM modules 20) for CDC-ROADM applications. Flexibility in add/drop requirements has led to so-called colorless, directionless, and optionally contentionless add/drop multiplexer structures, such as in ROADM devices, nodes, architectures, and structures. A colorless add/drop device supports any wavelength or spectral occupancy/band being added to any port of an add/drop device, i.e., ports are not wavelength specific. A directionless add/drop device supports any port being directed to any degree. Finally, a contentionless add/drop device supports multiple instances of the same channel (wavelength) in the same device (albeit to different degrees). A colorless, directionless add/drop device can be referred to as a CD device, and a colorless, directionless, and contentionless add/drop device can be referred to as a CDC device. Also, the channel multiplexer/demultiplexer modules 22 are referenced as modules 22C, 22L, 22CL, where the suffix C, L, and CL denote the components support the C-band, the L-band, and both the C-band and the L-band in an integrated manner, respectively. Also, the channel multiplexer/demultiplexer modules 22 are illustrated as a single layer, and those skilled in the art will recognize various different multiplexer/demultiplexer structures are possible, including layered approaches.
Finally, the fiber interconnect modules 24 are passive modules that support fiber connectivity between the ROADM modules 20 and the channel multiplexer/demultiplexer modules 22. That is, the fiber interconnect modules 24 is a fiber shuffler and can be used with high-density fiber cables such as Multi-fiber Push On (MPO) cables. The function here is to reduce cabling and provide a single point of interface similar to Fiber Distribution Panels (FDP). Of note, the fiber interconnect modules 24 can be referred to a fiber interconnect 30 between the ROADM modules 20 and the channel multiplexer/demultiplexer modules 22. Specifically, the present disclosure relates to a band splitter 40 in the fiber interconnect 30 or the fiber interconnect modules 24, and the present disclosure does not necessarily need the band splitter 40 in a module (the fiber interconnect modules 24) nor does the fiber interconnect 30 have to be in a module (the fiber interconnect modules 24).
The following describes connectivity between the modules 20, 22, 24. The illustrations in
The ROADM modules 20 include a line port 50 that connects to external optical fibers, i.e. the line side 12, and a plurality of connection ports 52. The channel multiplexer/demultiplexer modules 22 include local add/drop ports 54 and degree ports 56. Note, the various ports are given different names to help distinguish. The local add/drop ports 54 ultimately connect to the local optical modems, transceivers, transponders, etc. There may also be inline pre-combiner devices as well, such as described in commonly-assigned U.S. patent application Ser. No. 16/567,023, filed Sep. 11, 2019, and entitled “Upgradeable colorless, directionless, and contentionless optical architectures,” the contents of which are incorporated by reference in their entirety. The degree ports 56 on the channel multiplexer/demultiplexer modules 22 connect to the connection ports 52 on the ROADM modules 20. Again, the fiber interconnection modules 24 are used to streamline the connections between the degree ports 56 and the connection ports 52, as a fiber shuffler supporting high-density cabling. Generally, the interconnectivity between the degree ports 56 and the connection ports 52 can be referred to as the fiber connectivity 20.
Assuming a full-fill of each of the C-band and the L-band is 32 channels total per band or 64 channels total. If a node utilizing the ROADM degree 10A had eight degrees (8D) or twelve degrees (12D), the node would support 100% local add/drop. Now, for sixteen degrees (16D), the node would only support 75% local add/drop. That is, the more degrees, the more connection ports 52 are needed for degree-to-degree connectivity, thereby limiting the connectivity to the channel multiplexer/demultiplexer modules 22 for local add/drop. Stated differently, the connection ports 52 are used for either local add/drop or for degree-to-degree connectivity. Having separate C&L band ROADM modules 20C, 20L results in more available connection ports 52.
C&L band ROADM architectures are proving very popular as the need for bandwidth continues to grow. There is a desire for cost and component reduction to improve integration. The ROADM degree 10B in
While significantly reducing cost and components, the ROADM module 20CL effectively has half the number of connection ports 52 as with both the ROADM modules 20C, 20L, e.g., 32 connection ports 52 for the ROADM module 20CL versus 64 connection ports 52 for the ROADM modules 20C, 20L. The ROADM module 20CL shares the connection ports 52 across both bands. A given connection port 52 port would be C-band or L-band based on the channel multiplexer/demultiplexer modules 22C, 22L used.
Stated differently, in the parallel design of the ROADM degree 10A, there are 32 C-band ports 52 in the ROADM module 20C and 32 L-band ports 52 in the ROADM modules 20L which results in a total of 64 WSS ports. With the ROADM module 20CL approach, there are now 32 ports 52 in total across both bands. This results in a lower number of channel multiplexer/demultiplexer modules 22C, 22L attachment points causing a lower add/drop capacity.
Assuming the full-fill of each of the C-band and the L-band is 32 channels total per band or 64 channels total, as above. If a node utilizing the ROADM degree 10B had eight degrees (8D), the node would support 100% local add/drop. But, for twelve degrees (12D), the node would support 94% local add/drop, and, for sixteen degrees (16D), the node would only support 38% local add/drop. Thus, the cost reduction of the integrated ROADM module 20CL comes at the expense of reduced local add/drop capability.
The present disclosure addresses and recovers the local add/drop capability lost by reducing the port count in the ROADM module 20CL. Because the ROADM degree 10A has 2× the number of connection ports 52 as the ROADM degree 10B, it can connect to 2× the number of channel multiplexer/demultiplexer modules 22C, 22L, whereas the ROADM degree 10B can only connect to X the number of channel multiplexer/demultiplexer modules 22C, 22L.
To address add/drop scaling, the present disclosure contemplates use of a band splitter 40 in between the ROADM module 20CL and the channel multiplexer/demultiplexer modules 22C, 22L.
The band splitter 40 is a passive device that optically performs a 2:1 splitting and 1:2 combining of the C-band and the L-band. The band splitter 40 includes 3 ports 60, 62, 64 including a common port 60, a C-band port 62, and an L-band port 64. The common port 60 connects to one of the connection ports 52 on the ROADM module 20CL, the C-band port 62 connects to the channel multiplexer/demultiplexer module 22C, and the L-band port 64 connects to the channel multiplexer/demultiplexer module 22L.
With the band splitter 40, assuming a full-fill of each of the C-band and the L-band is 32 channels total per band or 64 channels total. If a node utilizing the ROADM degree 100 had 32-channels with eight degrees (8D) or twelve degrees (12D), the node would support 100% local add/drop. Now, for sixteen degrees (16D), the node would only support 75% local add/drop. That is, the ROADM degree 10C has the same add/drop capability as the ROADM degree 10A while having half the connection ports 52.
The first step in integration is the ROADM module 20CL, but
In an embodiment, a degree 10A includes ROADM components 20CL including a line port 50 and a plurality of connection ports 52; channel multiplexer/demultiplexer components 22C, 22L including degree ports 56 and local add/drop ports 54; and one or more band splitters 40 in between the ROADM components 20CL and the channel multiplexer/demultiplexer components 22C, 22L.
The ROADM components 20CL can include integrated C-band and L-band functionality. The ROADM components 20CL can include integrated C-band and L-band functionality, and the channel multiplexer/demultiplexer components 22C, 22L are separate for the C-band and L-band functionality. The ROADM components 20CL can include two Wavelength Selective Switches (WSSs) that support integrated C-band and L-band functionality.
Each of the one or more band splitters 40 include three ports 60, 62, 64 with a common port 60 configured to connect to one of the plurality of connection ports 52, a C-band port 62 configured to connect to a degree port 56 of C-band channel multiplexer/demultiplexer components 20C, and an L-band port 64 configured to connect to a degree port 56 of L-band channel multiplexer/demultiplexer components 22L.
The band splitter 40 can be configured to split/combine C-band spectrum and L-band spectrum. The band splitter 40 can be a passive fiber device. The band splitter 40 can be integrated into a fiber shuffler 24 located between the ROADM components 20CL and the channel multiplexer/demultiplexer components 22C, 22L.
In another embodiment, a ROADM node includes one or more degrees 10C configured to connect to optical fibers in an optical network. Degree-to-degree connectivity is via connections between the connection ports 52 of the respective degrees 10C.
The ROADM module 20CL includes only two WSSs that support spectrum across both the C-band and the L-band. As mentioned before, the WSSs are significant cost and the ROADM module 20CL reduces the number of WSSs by half.
The ROADM components can include integrated C-band and L-band functionality and the channel multiplexer/demultiplexer components are separate for the C-band and L-band functionality. Each of the one or more band splitters include three ports with a common port configured to connect to one of the plurality of connection ports, a C-band port configured to connect to a degree port of C-band channel multiplexer/demultiplexer components, and an L-band port configured to connect to a degree port of L-band channel multiplexer/demultiplexer components.
It will be appreciated that some embodiments described herein may include or utilize one or more generic or specialized processors (“one or more processors”) such as microprocessors; Central Processing Units (CPUs); Digital Signal Processors (DSPs): customized processors such as Network Processors (NPs) or Network Processing Units (NPUs), Graphics Processing Units (GPUs), or the like; Field-Programmable Gate Arrays (FPGAs); and the like along with unique stored program instructions (including both software and firmware) for control thereof to implement, in conjunction with certain non-processor circuits, some, most, or all of the functions of the methods and/or systems described herein. Alternatively, some or all functions may be implemented by a state machine that has no stored program instructions, or in one or more Application-Specific Integrated Circuits (ASICs), in which each function or some combinations of certain of the functions are implemented as custom logic or circuitry. Of course, a combination of the aforementioned approaches may be used. For some of the embodiments described herein, a corresponding device in hardware and optionally with software, firmware, and a combination thereof can be referred to as “circuitry configured to,” “logic configured to,” etc. perform a set of operations, steps, methods, processes, algorithms, functions, techniques, etc. on digital and/or analog signals as described herein for the various embodiments.
Moreover, some embodiments may include a non-transitory computer-readable medium having instructions stored thereon for programming a computer, server, appliance, device, one or more processors, circuit, etc. to perform functions as described and claimed herein. Examples of such non-transitory computer-readable medium include, but are not limited to, a hard disk, an optical storage device, a magnetic storage device, a Read-Only Memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically EPROM (EEPROM), Flash memory, and the like. When stored in the non-transitory computer-readable medium, software can include instructions executable by one or more processors (e.g., any type of programmable circuitry or logic) that, in response to such execution, cause the one or more processors to perform a set of operations, steps, methods, processes, algorithms, functions, techniques, etc. as described herein for the various embodiments.
Although the present disclosure has been illustrated and described herein with reference to preferred embodiments and specific examples thereof, it will be readily apparent to those of ordinary skill in the art that other embodiments and examples may perform similar functions and/or achieve like results. All such equivalent embodiments and examples are within the spirit and scope of the present disclosure, are contemplated thereby, and are intended to be covered by the following claims. Moreover, it is noted that the various elements, operations, steps, methods, processes, algorithms, functions, techniques, etc. described herein can be used in any and all combinations with each other.
Number | Name | Date | Kind |
---|---|---|---|
5892615 | Grubb et al. | Apr 1999 | A |
5905745 | Grubb et al. | May 1999 | A |
6115403 | Brenner et al. | Sep 2000 | A |
6275632 | Waarts et al. | Aug 2001 | B1 |
6407863 | Archambault et al. | Jun 2002 | B1 |
6459516 | Mizrahi et al. | Oct 2002 | B1 |
6614959 | Mizrahi et al. | Sep 2003 | B1 |
6618193 | Boertjes | Sep 2003 | B1 |
6795607 | Archambault et al. | Sep 2004 | B1 |
7231107 | Zhong et al. | Jun 2007 | B1 |
7254327 | Zhong et al. | Aug 2007 | B1 |
7693357 | Marrakchi El Fellah et al. | Apr 2010 | B2 |
7809272 | Zhong et al. | Oct 2010 | B2 |
7962049 | Mateosky et al. | Jun 2011 | B2 |
8364036 | Boertjes et al. | Jan 2013 | B2 |
8457497 | Zhong et al. | Jun 2013 | B2 |
8509618 | Boertjes et al. | Aug 2013 | B2 |
8509621 | Boertjes et al. | Aug 2013 | B2 |
8554074 | Boertjes et al. | Oct 2013 | B2 |
8625994 | Archambault et al. | Jan 2014 | B2 |
8750706 | Boertjes et al. | Jun 2014 | B2 |
8817245 | Archambault et al. | Aug 2014 | B2 |
8958696 | Boertjes et al. | Feb 2015 | B2 |
9077474 | Boertjes et al. | Jul 2015 | B2 |
9419708 | Rad et al. | Aug 2016 | B2 |
9577763 | Al Sayeed et al. | Feb 2017 | B2 |
9680569 | Archambault et al. | Jun 2017 | B2 |
9768902 | Al Sayeed et al. | Sep 2017 | B2 |
9831947 | Boertjes | Nov 2017 | B2 |
9973295 | Al Sayeed et al. | May 2018 | B2 |
10236981 | Harley et al. | Mar 2019 | B2 |
10237011 | Al Sayeed et al. | Mar 2019 | B2 |
10237633 | Chedore et al. | Mar 2019 | B2 |
10250326 | Bao et al. | Apr 2019 | B2 |
10263386 | Sridhar et al. | Apr 2019 | B1 |
10277311 | Archambault et al. | Apr 2019 | B2 |
10277352 | Chedore et al. | Apr 2019 | B2 |
10374704 | Archambault et al. | Aug 2019 | B2 |
10404365 | Frankel et al. | Sep 2019 | B2 |
10411796 | Archambault et al. | Sep 2019 | B1 |
10454609 | Chedore et al. | Oct 2019 | B2 |
10455300 | Swinkels et al. | Oct 2019 | B2 |
10536235 | Al Sayeed et al. | Jan 2020 | B2 |
10615867 | Bhatnagar et al. | Apr 2020 | B1 |
10630417 | Chedore et al. | Apr 2020 | B1 |
10680739 | Swinkels et al. | Jun 2020 | B2 |
10746602 | Pei et al. | Aug 2020 | B2 |
10778329 | Chedore et al. | Sep 2020 | B1 |
10784980 | Roberts et al. | Sep 2020 | B2 |
10826601 | Bhatnagar et al. | Nov 2020 | B2 |
10868614 | Al Sayeed et al. | Dec 2020 | B2 |
20030042402 | Boertjes et al. | Mar 2003 | A1 |
20040151426 | Boertjes et al. | Aug 2004 | A1 |
20070212064 | Boertjes et al. | Sep 2007 | A1 |
20110116790 | Sakauchi | May 2011 | A1 |
20150229404 | Boertjes | Aug 2015 | A1 |
20150229528 | Swinkels et al. | Aug 2015 | A1 |
20160080084 | Boertjes et al. | Mar 2016 | A1 |
20180234749 | Chedore | Aug 2018 | A1 |
20180239522 | Campbell et al. | Aug 2018 | A1 |
20200007262 | Chedore et al. | Jan 2020 | A1 |
20200374001 | Chedore et al. | Nov 2020 | A1 |
20210263218 | Robertson | Aug 2021 | A1 |
Number | Date | Country |
---|---|---|
2189568 | Oct 2002 | CA |
0733223 | Sep 1996 | EP |
1078487 | Mar 2006 | EP |
2682730 | Jan 2014 | EP |
2564532 | Oct 2017 | EP |
1994019713 | Sep 1994 | WO |
2002082706 | Oct 2002 | WO |
2010012100 | Feb 2010 | WO |
2020112258 | Jun 2020 | WO |
Entry |
---|
Emmerich et al., “Capacity Limits of C+L Metro Transport Networks Exploiting Dual-Band Node Architectures”, OFC 2020, OSA 2020 (Year: 2020). |