Monitoring and testing solutions for the industry to build, deploy, and manage passive networks.

VIAVI provides the industry with DWDM testing solutions to build, deploy and manage passive DWDM network environments.

How VIAVI Enables DWDM Network Systems 

Dense Wavelength Division Multiplexing (DWDM) represents a milestone in the evolution of fiber optic transmission technology. Single-mode optical fiber communication has evolved to improve network reach (distance), innovative modulation formats have increased carrying capacity, and DWDM has increased wavelength utilization and efficiency.

DWDM Network Construction

Verification of DWDM network and channel performance is critical at the start of the network lifecycle. We partner with wireless, cable and Telco service providers to help them push fiber connections and network elements closer to subscribers. DWDM allows C-RAN/5G, Hybrid Fiber Coax (HFC), Distributed Access Architecture (DAA), and submarine cable networks to utilize existing fibers more efficiently, reduce new fiber consumption and deliver the capacity needed.

  • DWDM deployment is also essential for meeting the speed and bandwidth requirements of access, metro and core/long haul networks. 
  • Hyperscale and multi-tenant data center (MTDC) operators are deploying high-capacity DWDM solutions for their data center interconnects (DCIs).

VIAVI helps development teams, operators, and service providers thrive as the use of DWDM accelerates. With advanced features, automation, and intuitive workflows, versatile VIAVI test solutions improve DWDM performance and reliability from the lab to the field. 

DWDM Use Case Solutions

Dense wave division multiplexing combines cutting edge laser optics, electronics, and modulation technologies to maximize the efficiency of optical fiber data transmission. Successful DWDM deployments are the end result of collaboration, innovation, and a step-by-step approach to development, installation, testing, and maintenance practices.

Network Installation:

Inspection, fiber testing and certification of all DWDM elements, core/common fiber and MUX/de-MUX components prior and during installation, plus end-to-end verification of the completed DWDM network, through MUX and De-MUX, will ensure first time service activation and reliable operation. 

  • The FiberChek Probe microscope is a handheld solution that allows you to inspect and verify the entire fiber end face using auto-focus, intuitive pass/fail analysis, convenient data storage, and automated fiber inspection workflows.
  • Conventional fiber optic tools include visual fault locators (VFL) to highlight breaks, bends, and localized damage and  OTDR testing equipment using standard 1310/1550nm test wavelengths to characterize and locate losses from connection/splice points or bends in the main/core/common fibers prior to connecting the MUX/De-MUX components. 
  • Specialized OTDR tools, including the VIAVI DWDM OTDR module, operate at exact DWDM service wavelengths as once MUX/De-MUX connections have been completed the standard 1310 & 1550nm wavelengths are filtered out and cannot be used. Specific routes are validated and characterized end-to-end using a tunable C-band OTDR laser. 
  • The Smart Link Mapper (SLM) removes the trouble of interpreting an OTDR trace and delivers a simple icon-based view of the DWDM link under test. Common DWDM link components/elements and any faults are clearly identified during the pre-turn-up continuity test or during maintenance/troubleshooting.

DWDM Turn-up Testing

  • A DWDM Optical Channel Checker Module can be used to program SFP/SFP+ optics, verify channel performance and wavelength provisioning over live metro/access links. 
  • An Optical Spectrum Analyzer (OSA) verifies transmitted wavelengths, power levels, and OSNR for active ROADM or amplified systems. 
  • The OSA-110 features full-band measurement capability, high optical resolution, and built-in calibration to ±.05nm accuracy.
  • The Nano OSA is the smallest and toughest field ready spectral test solution offering high resolution, full band coverage for C/D/L/MWDW channel analysis for today and tomorrows Metro and Access network applications.

Network Monitoring with a Remote Fiber Test System

A remote fiber test system provides automated, around-the-clock OTDR monitoring in a rack-mounted solution. DWDM fiber links can be scanned continuously or on demand for specific 5G, FTTH, and high-speed business applications.

  • The VIAVI FTH-5000 tests over dedicated 1625-1650 nm wavelengths to avoid interfering with active DWDM transmissions.  
  • The FTH-9000 or OTU-8000 test system can be configured with a tunable DWDM module and can test multiple DWDM networks/links. Monitoring can be performed by using a dark fiber in the same cable or on live network using a reserved DWDM test wavelength/MUX port. These can also test at dedicated 1625-1650 nm wavelengths to avoid interfering with active DWDM transmissions. 
  • The highly scalable ONMSi RFTS Fiber Test Heads, including the FTH-5000 and the FTH-9000, free up valuable technical resources while providing detailed, instant fault alerts and location details.


  • The ONMSi remote fiber test software for core, access, metro, and FTTH applications controls and tracks the data obtained by the OTUs for a network wide view of fiber health and issue resolution progress. This centralized, high-visibility solution can be leveraged for construction testing, long-term performance monitoring, and intrusion detection (security).
  • Any FTH can operate as an independent, stand-alone solution for continuous in-service fiber or dark fiber monitoring and fault detection. The FTH can be deployed out of the box without a server or training requirements, making it an ideal solution for small, private networks or single links. As the network grows, you can add the ONMSi server and analytics to capture long-term trends, robust reporting and analytics, and apply central management and user permissions in order to auto-assign work to the right network team by region, domain, shift schedule to ensure alerts are sent and prioritized by the right team.

DWDM Troubleshooting

Locating and repairing faulty Dense Wavelength Division Multiplexing (DWDM) network links quickly, and without disrupting existing traffic, is the key to avoiding excessive downtime or SLA penalties.

  • OTDR tests at specific unused DWDM wavelengths can be performed on the live network to avoid service interruptions and to locate any physical layer issues.
  • Optical Channel Checkers (OCC) and OSA solutions elevate DWDM OTDR troubleshooting by using power and wavelength analysis to identify transmission anomalies.
  • Innovative, versatile test solutions with additional features to validate SFP/SFP+ transceivers or program tunable transceiver devices significantly reduce activation time and Mean Time to Repair (MTTR).

DWDM Solutions From VIAVI

As you continue to design, build, and maintain the next generation DWDM fiber networks, end-to-end test solutions from VIAVI add value throughout the network lifecycle.

We help operators build confidence in correctly installed network links, improved first-time activation success rates, and ongoing performance assurance. DWDM OTDR modules, Channel Checkers, and OSA test solutions collectively enhance the ability to verify or provision any DWDM channel quickly and accurately, even through installed MUX/De-MUX. OPEX and MTTR are reduced through cutting-edge troubleshooting capabilities that distinguish between fiber and network elements and accurately identify impacted wavelengths.

DWDM is the key to unlocking unprecedented fiber capacity and leveraging existing fiber assets. Together we are making this vision of the future a reality.

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