Optelian optical networking solutions draw from a range of technologies for optical networking. Networking functions and capabilities are realized using a variety of network element types, each using state-of-the-art technology for achieving the desired functionality.
Optelian’s optical filter portfolio includes a complete range of optical multiplexers, demultiplexers, and optical add-drop multiplexers (OADMs). Multiplexers/Demultiplexers allow multiple wavelengths to be combined onto, or extracted from, a single fiber. OADMs allow a selected wavelength or subset of wavelengths to be added or dropped from a composite WDM signal, providing for efficient wavelength grooming and wavelength routing. Such devices require no power, and can operate over extended temperature ranges in harsh environments. Solutions are available for simple 1310/1550 nm wave division multiplexing (WDM), Coarse Wave Division Multiplexing (CWDM), or full Dense Wave Division Multiplexing (DWDM) with up to 80 wavelengths, as well as multiplexers for applications such as G-PON, E-PON or NG-PON2. Optelian’s optical filtering solutions use state-of-the-art thin-film filter (TFF) technology and Athermalized Array Waveguide Gratings (AAWGs), offering performance with wide bandwidths, wide temperature range, exceptional isolation and very low insertion loss.
Optical Power Splitters and Combiners
Many types of passive splitters and combiners are offered, ranging from 1×2 up to 1×64. These are available in various form factors, and with different mounting and connectorization options. They are able to operate over an extended temperature range in harsh environments, and are ideally suited for realizing an Optical Distribution Network (ODN) in PON applications.
Dispersion Compensation Modules
Many of today’s networks need to support coherent transceiver technologies for 100G+ wavelengths along with commoditized 10G transceivers, such as DWDM SFP+ or XFP, on the same optical transport infrastructure. Optelian’s dispersion compensation modules (DCMs) are based on periodic Fiber Bragg Grating (FBG) technology, making them an ideal choice for mixed 10/100/200/400G transmission. Unlike legacy dispersion compensating fiber (DCF), FBG-based DCMs are much more tolerant to nonlinear transmission impairments, and they introduce negligible delay, have very low insertion loss, are very compact and require no power to operate. Using Optelian’s specialized engineering rules for the selection and placement of DCMs, it is possible to build a network that supports all-optical transmission over any topology for all bit rates and transceiver types, avoiding the need for expensive optical-electrical-optical (OEO) regeneration.
Optical amplifiers allow for all-optical transmission over distances of many hundreds or even thousands of kilometers. Optelian provides a complete portfolio of Erbium doped fiber amplifiers (EDFAs) that are gain flattened with fast transient control. Single-stage and dual-stage variants are available with different gain and power ratings, allowing a network to be designed using an optimal amplifier type for different span losses. The result is a lower cost network with a much higher optical signal-to-noise ratio (OSNR) for circuit paths, which significantly mitigates, or even eliminates, the need for OEO regeneration. The cost savings from the use of properly selected and placed optical amplifiers can be astounding, especially as networks transition to 100G and beyond.
Reconfigurable OADMs (ROADMs)
Network automation through the use of ROADMs provides significant operational and robustness benefits to a network, and the ability to realize new circuits in a fraction of the time otherwise possible. A core technology used in ROADMs is a wavelength selective switch (WSS), which allows any wavelength or combination of wavelengths to be remotely provisioned between one physical optical port and multiple other physical optical ports, and to dynamically control and adjust the attenuation of each wavelength independently with very fine granularity. ROADMs allow wavelengths to be provisioned remotely and dynamically on demand. They also provide automated power balancing and control with per-wavelength granularity, eliminating the complex task of optical power management and control in an optical network. Optelian provides ROADM solutions ranging from simple terminal or two-degree ROADM elements, to full multi-degree ROADMs for rich mesh network architectures and topologies. They can work on 100 GHz, 50 GHz or flexible grid channel plans. The WSS building block of a full ROADM can also be used to implement an optical line amplifier with per-wavelength equalization capabilities, and which is in-service upgradable to full ROADM functionality.
Transponders and Regenerators
Transponders are used to convert an optical signal from one optical interface type to another. A common application is to convert a short-reach “grey” interface, such as 850 nm multimode or 1310 nm, to a DWDM signal for long-distance transport. Transponders may also be used to convert between, e.g., CWDM and DWDM interfaces. Transponders may be fully “transparent,” whereby the conversion is pure OEO conversion from one interface type to another, or they may be OTN-based, whereby the converted signal is wrapped into an OTU framing structure to provide forward error correction (FEC) and enhanced service OAM for the transported signal. OTN transponders, such as Optelian’s RGN-8040, can reach very longer distances without OEO regeneration, and provide comprehensive performance monitoring for both the client and line signals. OTN transponders support a wide range of client protocols, and are ideally suited when clear transport demarcation visibility is required with comprehensive performance monitoring and service level assurance. They are an ideal solution for offering error-free wavelength services with complete monitoring capabilities and high service level assurance. Transparent transponders, such as Optelian’s RGN-8010, introduce negligible latency (sub 50 ns), and work with any protocol over a very wide range of data rates. Transparent transponders are a good solution when service monitoring is already provided on other equipment, and where the minimization of latency is essential, such as with CPRI front haul or financial fast trading. Regenerators are similar to transponders, except that the interface type being “transponded” is the same at each interface port. Their purpose is to simply regenerate a signal in order to extend transmission distance, thereby overcoming the limitations of noise and signal distortion. Both transparent and OTN regeneration is possible, and it is also possible to use a transparent regenerator in conjunction with OTN transponders to get the benefits of both types of technology. Optelian’s RGN-8040 and RGN-8010 can function as a transponder or regenerator.
Muxponders combine multiple client optical interfaces into a common line optical interface operating at a higher data rate over a single wavelength. Hence, their primary purpose is to fully utilize the bandwidth available on a transmitted wavelength. With this approach, multiple lower-speed optical signals are converted to electrical signals, and then electrically multiplexed into a higher speed electrical signal, which is then transponded onto an optical interface, such as CWDM or DWDM. The combination of multiplexing and transponding is the origin of the name “Muxponder”. Muxponders can accommodate essentially any disparate mix of client protocols, including Ethernet, Fibre Channel, CPRI, or SONET/SDH, and they provide comprehensive performance monitoring for both client and line-side signals, with OTN-wrapping capabilities to extend reach and provide for error-free transmission. Muxponders are usually used in a “bookended” configuration, whereby a muxponder is placed at each end of a transmission link. Optelian’s FLX-1610 provides multiprotocol muxponding of client data rates from 100 Mb/s to 4.25 Gb/s onto a 10 Gb/s wavelength with OTN encapsulation. Optelian’s MPX-9110 provides multiprotocol muxponding of 8/10/40 Gb/s client signals onto a fully-tunable 100 Gb/s coherent wavelength, while the MPX-9103 provides the same muxponding capabilities onto a non-coherent 100G line signal, such as 100 Gb/s SR10 or LR4.
Multiprotocol Add-Drop Multiplexers
Multiprotocol add-drop multiplexers (ADMs) are similar to muxponders, except they have two line interfaces. The line interfaces are interconnected over optical links in a linear or ring topology, thereby providing a simple overlay network that can provide any-to-any circuit provisioning for a diverse mix of client protocols. The circuits provide true private line services with very low latency and fixed, deterministic bandwidth. In a ring topology, each ADM network element has an east and west line interface, allowing for 1+1 protection of any or all circuits. Similar to muxponders, full performance monitoring and OTN wrapping capabilities are provided. ADMs can also be used in a bookended configuration where they function as muxponders, but with up to twice the line-side capacity using two wavelengths. Optelian’s FLX-1610 is a multiprotocol ADM with 2x10G line interfaces.
Most Optelian networking products use pluggable transceivers for client- and line-side interfaces. This offers complete flexibility for the optical interface type needed on a given networking platform. Options are available for different form factors and data rates using SFP, SFP+, XFP and CFP pluggable modules. Modules may be grey for short reach client connections, using 850 nm multimode or 1310 nm single-mode optics, or they may be CWDM or DWDM for longer distance transport. Moreover, fully-tunable DWDM transceivers are available in SFP+ and XFP module types, and all module types have an option for industrial temperature grade, allowing them to operate in extended temperature applications in harsh environments. Optelian provides DWDM optical modules that can transport signals over distances up to 120 km without optical amplification. When used with optical amplifiers and DCMs, optical signals from pluggable transceivers can be transmitted over many hundreds of kilometers without OEO regeneration.
Network Management System
In addition to a standard command line interface (CLI) and Web craft interface for managing individual network elements, Optelian also offers a full-featured client-server network management system for centralized monitoring and surveillance of large networks containing up to many hundreds of network elements (shelves). Network elements are automatically discovered, and the NMS provides a dashboard for event logging, alarm status, network inventory management, performance monitoring and the remote configuration and provisioning of all network elements under one management and control domain. The NMS also provides for centralized software updates that are fully automated, without affecting the continuity of services. The NMS provides full database backup-and-restore capabilities, with DB duplication and/or server redundancy to protect against an NMS server failure. Optelian equipment also offers robust data communication network (DCN) capabilities with options for an optical supervisory channel (OSC) and multi-path reachability of NEs over the DCN, thereby offering increased resiliency and network visibility in the presence of faults, such as fiber cuts or power failures.