What is the difference between DWDM and OTN? You will know after reading this. Global communications are advancing by leaps and bounds, the role of communication networks is becoming more and more important, and communication network construction needs to be continuously expanded. At present, DWDM (Dense Wavelength Division Multiplexing) and OTN (Optical Transport Network) technologies are widely used in network communication construction. DWDM technology has greatly improved the transmission capacity of optical fiber networks. However, it is insufficient in optical domain signal processing and business scheduling, and cannot meet the high standards of broadband data services. As an evolutionary product of DWDM technology, OTN has a variety of customer signal encapsulation and transparent transmission, large-granular bandwidth multiplexing, flexible cross-connection and configuration scheduling, powerful overhead and maintenance management capabilities, and enhanced networking and protection capabilities. The unique advantages of OTN equipment have gradually replaced DWDM equipment. The following is a brief discussion on the comparison of DWDM and OTN transmission technologies. 1. The conceptual difference between DWDM and OTN. DWDM: Dense Wavelength Division Multiplexing (DWDM) is a laser technology that combines multiple light waves into a set of optical wavelengths and uses one optical fiber for transmission near the wavelength window of 1550nm and within the range that EDFA can provide gain. It is a laser technology that improves bandwidth on optical fiber backbone networks. Rather, the technology multiplexes the closely spectral spacing of individual fiber carriers within a given fiber in order to take advantage of the achievable transmission performance (e.g., to achieve minimal dispersion or attenuation). In this way, the total number of optical fibers required can be reduced for a given information transmission capacity. OTN (Optical Transport Network) is a transport network that organizes networks at the optical layer based on wavelength division multiplexing technology. It is the next generation backbone transport network. The OTN switching module is added to this technology, so that the system can flexibly schedule communication services, expand, promote, and increase client information, and improve the business capabilities of network communications, thus solving the problems of traditional WDM networks with poor wavelength/sub-wavelength service scheduling capabilities, weak networking capabilities, and weak protection capabilities. 2. Different signal formats. DWDM technology does not have a corresponding frame structure. During operation, the wavelength of a single signal is converted into the corresponding wavelength in network communication through a converter, and the transmission wavelength is multiplexed through optical technology. OTN has a complete frame structure. It uses electrical crossover technology to schedule wavelengths to achieve an electrical crossover function similar to SDH, so that small-particle signals can be merged and transmitted in large channels. An OTN channel also has large and small containers like SDH. OTN has the ability to access and process from an institutional perspective, improving bandwidth utilization efficiency. OTN technology can also monitor the working performance, faults and other issues of the network communication power regeneration part. In the process of performance fault detection, OTN technology is more superior. 3. Differences in networking and protection mechanisms. DWDM technology networking methods are mainly point-to-point, chain, star, and ring networking. In terms of protection methods, only grassroots protection is provided. The protection methods are mainly optical multiplex section protection, and 1+1 and 1:1 protection are used on the optical path. Terminal equipment is not protected. This protection method requires two independently routed optical cables. DWDM's self-healing protection of services is performed in the SDH ring network. OTN networking is usually ring networking, mesh and other networking methods, which can provide line 1+1 protection, wavelength 1+1 protection, client side 1+1 protection, ODUk protection, optical layer and electrical layer protection, etc. 4. In terms of business scheduling capabilities, data configuration can be used in OTN for cross-connection (similar to SDH business configuration), multiple types of services can be accessed at the same time, and intelligent scheduling of services can be realized. It can provide hybrid scheduling capabilities for optical layer wavelength level and electrical layer sub-wavelength level services. Optical layer scheduling capability: The optical layer provides OADM wavelength scheduling method, which can pre-plan the input/output of fixed wavelengths, or use AWG to input/output all wavelengths. The wavelengths of upstream and downstream services need to be connected to the service board, and there is no need to use pigtail jumper scheduling for the wavelengths of upstream and downstream services. Electrical layer scheduling capability: Provides distributed electrical cross-connection of ODU0/ODU1/ODU2/ODU2e/ODU3/ODU4 particles, with the cross-connect capacity of adjacent slots reaching 100/200Gbps. 5. Application scenarios DWDM is mainly used in inter-provincial trunk networks and intra-provincial backbone networks. It mainly adopts point-to-point networking method, which can realize line protection. If the line protection method is used, more lines need to be laid, which is costly. Therefore, DWDM's self-healing protection of services is combined with the SDH ring network and is widely used. The OTN network provides an ideal solution for large broadband granular services. OTN networks are deployed in the inter-provincial backbone network, intra-provincial backbone network, and metropolitan core layer of telecom operators, and provide scheduling of business granules above Gb/s. The inter-provincial backbone network carries long-distance services such as PSTN/2G/3G/4G/internet. The use of OTN networks can implement various forms of protection methods and has strong protection capabilities The provincial backbone network carries services such as NGW/3G/4G/IPTV large customer dedicated lines between backbone routers, and the metropolitan area core network carries large-granularity services between the local network core router and the aggregation router. By building the provincial backbone network OTN and the metropolitan area network core layer OTN network. 6. The advantages of Fibercom's DWDM and OTN. The Fibercom 4U active wavelength division system can greatly increase network capacity and make full use of optical fiber resources. The transmission rate of a single wavelength is 1.25Gbit/s to 100Gbit/s, the number of service channels reaches 96 waves, and a variety of networking methods can be configured. The 4U active wavelength division system is composed of wavelength conversion modules, wavelength division optical modules, combiners, demultiplexers, fiber amplifiers, dispersion compensators, network management units and other components, which together complete the sending, shaping, transmission and reception of network signals to form a stable DWDM transmission system. It has the characteristics of flexible networking, good scalability, security and stability, and diverse and flexible management methods. Fibercom's 4U active wavelength division system products have rich practical experience in applications in backbone networks, municipal telecom operators, State Grid, military private networks, security monitoring, university education networks and other fields. Fibercom OTN2800 series is a new generation of wavelength division products launched to meet the optical transmission market. Smooth upgrade: supports multi-frame cascading and smooth expansion and upgrade capabilities, supports 10Gbit/s business upgrades to 100/200G bit/s services, supports 40-wave/80-wave smooth upgrade capabilities, and the maximum transmission capacity of a single optical fiber can be 8T/16T. Networking mode: OTN2800 can be flexibly configured as OTM (Optical Multiplexing Terminal), OLA (Optical Line Amplifier), REG (Electrical Relay), OADM (Optical Add-Drop Multiplexer) and other equipment types, and supports point-to-point, chain, ring and mesh networking modes. The advantages of the OTN2800 series (1) provide hybrid scheduling capabilities for optical layer wavelength level and electrical layer sub-wavelength level services (2) can achieve ultra-long span and ultra-long distance transmission capabilities, support multi-level cascading functions of electrical relay regeneration, and the relay regeneration transmission distance can reach tens of thousands of kilometers. (3) The 100G/200G single board of OTN2800 can provide wavelength adjustment function. The wavelength adjustment is realized through the adjustable wavelength module, which can be adjusted within the 96-wave range of 50GHz interval in the C-band. Wavelength adjustable machine technology avoids the traditional wavelength division fixed wavelength conversion method, which can greatly facilitate business opening and realize flexible wavelength allocation. (4) Supports mixed transmission of 10G, 100G, and 200G signals. OTN2800 supports the mixed transmission of the current mainstream rate 10G signals and 100G signals on the same platform, and provides a mature mixed transmission networking solution. Users can therefore flexibly network and realize smooth transition from 10G system to 100G system. In the design of the mixed transmission scheme, in addition to fully considering the common issues such as the transmission distance and channel spacing of the two-rate signals, the channel interference problem between different modulation formats is also comprehensively considered to ensure the transmission performance of the system. 6. The general trend of OTN is the continuous growth of informatization and business bandwidth. As a derivative of DWDM, OTN technology inherits and combines the advantages of SDH and WDM, and at the same time expands the networking functions that adapt to business transmission requirements. The network application, dispatching capabilities, business access capabilities, and network management monitoring capabilities have been significantly improved, which can meet the requirements of new service quality. The transparency of OTN system business transmission, super error correction capabilities, and flexible optical and photoelectric layer scheduling capabilities. With the advent of the 5G era, the application of OTN technology will become more and more popular in the market, which is an inevitable trend in future network development