Although DWDM technology greatly improves the transmission capacity of optical fiber network, it is insufficient in signal processing in optical domain and business scheduling, and cannot meet the high standard requirements of broadband data service. As an evolutionary product of DWDM technology, OTN has a variety of customer signal packaging and transparent transmission, large particle bandwidth reuse, flexible crossover and configuration scheduling, strong overhead and maintenance management ability, and enhanced networking and protection capabilities. OTN equipment has gradually replaced DWDM equipment with its unique advantages.
OTN (Optical Transport Network) is the next generation backbone Transport Network based on wavelength division multiplexing (WDM) technology. In this technology, OTN switching module is added to enable the system to flexibly schedule communication services, expand, promote and increase client information, and improve the business ability of network communication, so as to solve the problems of poor wavelength/sub-wavelength business scheduling ability, weak network networking ability and weak protection ability of traditional WDM network.
OTN have full frame structure, its own scheduling wavelength can be achieved through cross technology electric cross function, such as SDH, small particles of transmitted signals can be incorporated in the large channel, a channel OTN in also have greatly small container, like SDH OTN from system will have the ability to access and processing, improve the utilization efficiency of bandwidth. OTN technology can also supervise the working performance, fault and other problems of the regenerative part of network communication. In the process of performance fault detection, OTN technology is more superior.
OTN network is usually a ring network, network and other network forms, 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.
In OTN, data configuration can be used for cross-connection (similar to SDH‘s business configuration), and multiple types of services can be accessed at the same time to realizeintelligent business scheduling. It can provide optical layer wavelength level, electrical layer sub wavelength level business hybrid scheduling capabilities, optical layer scheduling capabilities.
OTN network has improved a very ideal solution for large broadband granular business. OTN network’s deployment has been carried out in the interprovincial backbone network, provincial backbone network and the core layer of urban area of telecom operation enterprises to provide scheduling of business particles above Gb/s.
OTN is a new generation of wave components for the optical transmission market. Smooth upgrade: support multi-frame cascade and smooth expansion upgrade ability, support 10Gbit/s service upgrade 100/200g bit/s service, support 40-wave / 80-wave smooth upgrade ability, single fiber maximum transmission capacity of 8T/16T.
The advantage of its OTN:
(1) Provide hybrid scheduling capability for wavelength level optical layer and wavelength level electrical layer.
(2) It can realize the transmission capability of ultra-long span and ultra-long distance, support the multi-level cascade function of electric relay regeneration, and the relay regeneration transmission distance can reach tens of thousands of kilometers.
(3) The 100G/200G veneer of OTN can provide wavelength adjustment function. The wavelength adjustment can be realized through the adjustable wavelength module, which can be adjusted within the range of 96 waves with 50GHz interval in C band. Wavelength adjustable machine technology avoids the traditional wave division fixed wavelength conversion, which can greatly facilitate the service opening and realize the flexible wavelength allocation.
(4) Users can flexibly network to realize the smooth transition from 10G system to 100G system. In terms of mixing scheme design, in addition to the common problems such as transmission distance and channel interval between two kinds of rate signals, channel interference between different modulation formats is also considered comprehensively to ensure the transmission performance of the system.
With the continuous growth of information level and service bandwidth, OTN, as a derivative product of DWDM, inherits and combines the advantages of SDH and WDM and expands the networking function suitable for service transmission requirements. In the network application, scheduling ability, business access ability, network management monitoring ability has been significantly improved, can meet the requirements of new business quality. With the coming of 5G era, the application of OTN technology will be more popular in the market, which is the inevitable trend of future network development.