What Is OTN — Optical Transport Network?

Posted on October 5, 2018

With the explosion of digital traffic and the ever-growing array of bandwidth-hungry applications, OTN (Optical Transport Network) evolves from point-to-point DWDM remedies to scalable and robust optical networking applications that cater to a wide variety of client signals with equally-varied service requirements. Carriers are also placing particular emphasis on OTN in the Metro area, where it is shifted rapidly from SONET/SDH to WDM (wavelength-division multiplexing). With the goal of boosting bandwidth and increasing network functionality, OTN provides a way to support different traffic types in a more cost-effective manner than by using SONET/SDH networks. What is OTN and how will the OTN-based solutions benefit your optical networking?

What Is OTN — Optical Transport Network

It is imperative to clearly define what is meant by the term OTN. OTN is defined by the ITU Telecommunication Standardization Sector (ITU-T). It’s a digital wrapper technology which provides an efficient and globally accepted way to multiplex different services onto optical light paths. The OTN technology or digital wrapper technology provides a network-wide framework that adds SONET/SDH-like features to WDM equipment. It creates a transparent, hierarchical network designed for use on both WDM and TDM devices. OTN integrates functions of transporting, multiplexing, routing, management, supervision, and builds OTN client (e.g. SONET/SDH, IP, ATM) connections in the Metro and Core networks.

OTN (Optical Transport Network)

Five Key Benefits of OTN Network

OTN network combines the advantages of optical transmission and electrical processing to provide end-to-end, transparent pipe connections, increased spectral efficiency, and large-capacity transmission capabilities for long-haul transmissions. The primary benefits of OTN network are presented as follows.

Standard Hierarchy–OTN standards include a standard multiplexing hierarchy, defining exactly how the lower-rate signals ascend into the higher-rate payloads. This allows the WDM platform to shift lower-rate services within 10Gbps, 40Gbps, or 100Gbps wavelengths, without the need for external wavelength demultiplexing and manual interconnects.

Transport Capacity Expansion–Providing the underlying high-capacity infrastructure for core interoffice, metropolitan interoffice, and broadband business-access networks. Carriers deploy OTN to support greatest number of services on least amount of infrastructure.

Reduced Cost–Transporting multiple clients on a single wavelength, while preserving their specific requirements, reduces the overall cost of transport and ensures efficient bandwidth utilization.

Transport Flexibility–Network operators can employ the technologies needed to support current transport demands, while also enabling future adoption of new technologies as business needs dictate. It can easily scale to ring networks, end to end networks and mesh networks.

Timing Transparency–Timing transparency is important for offering wholesale services for third-party providers. The transparency of OTN enables the networks to carry any service, including Ethernet, storage, digital video, as well as SONET/SDH without interfering with the client timing.

FS Optical Transport Network Solutions

FS optical transport network platform is engineered to support CWDM and DWDM based solutions for high-capacity optical links and conducive to save cabinet space. FS OTN solutions are associated with a comprehensive list of products to match the future-proofing fiber and network requirements of every individual network task. FS OTN-based products cover the WDM MUX/DEMUX, OADM, EDFA, OEO transponder, optical line protection card, variable optical attenuator, etc. based on various networking environments.







Description Provide high-performance signal division and multiplex Add/drop the selected wavelengths in one or multiple channels Extend the power budget over long distances 3R functionality (re-amplification, re-shaping, re-timing) Optical Line Protection for optical power monitoring and automatic switching Variable Optical Attenuator for optical power management

How to Get a Custom OTN Solution in FS?

FS.COM focuses on designing various optical transmission solutions to make your network farther, faster, smarter. To get a customized OTN solution in FS.COM, kindly submit the following three requirements about your project, then our experienced tech engineers will design the optimal OTN solution tailored to your specific needs.

Q1: How many spans do you have, and how far between each of the span?

The specific distance your network transports will determine the fundamental equipment that is needed. Specifically, the transmission distance between each span will indicate whether the DCM (Dispersion Compensation Module) would be needed to compensate in the fiber optical link.

Q2: What's your fiber type and the link loss (typical 0.25dB/KM)?

Our OTN solutions can be tailored to both dual and single fiber type. And link loss is necessary for collocating the most appropriate optical transceivers and some active components such as EDFA amplifiers.

Q3: What's the data rate between each span? And how many businesses do you plan to transmit?

To make clear the data rate and capacity for each span in your network is conductive to choosing the most practical types of MUX or OADM to for your current OTN infrastructure. And a good acquisition of the numbers of businesses you were to deploy can pave the way for future network expansion.


All in all, the OTN technology represents both a technical leap forward in optical networking over SONET/SDH and a business opportunity for carriers and service providers alike. OTN networks can fully leverage the transport infrastructure in the era of data/transport convergence by offering carriers unprecedented architectural flexibility, client-protocol independence, and service differentiation. To customize any OTN network solution, please contact us at sales@fs.com.

Related Article: FS Optical Transport Network Platform UnveilingCWDM vs DWDM: What’s the Difference?Passive DWDM vs. Active DWDM