OTN (Optical Transport Networking) transmission technology is a way of sending multiple data sources over the same optical channel using a digital wrapper. A digital wrapper is a layer of information that encapsulates the data and provides features such as error correction, timing, and multiplexing. OTN transmission technology can support different types of data, such as IP, Ethernet, SONET/SDH, and video, and can transport them over long distances using optical fibers. OTN transmission technology is based on two main technologies: TDM and WDM. TDM stands for Time Division Multiplexing, which is a method of dividing a single channel into multiple time slots, each carrying a different data source. WDM stands for Wavelength Division Multiplexing, which is a method of combining multiple channels with different wavelengths (colors) of light into a single optical fiber. By using TDM and WDM together, OTN transmission technology can achieve high speed and large capacity optical transmission.
OTN transmission technology has several advantages over its predecessor, SONET/SDH, which is another optical transmission technology that uses TDM only. OTN transmission technology can support higher throughput (up to 400Gbit/s per channel), better error correction, more flexible mapping of different data sources, and more efficient use of optical bandwidth. OTN transmission technology also provides a transparent and hierarchical network structure that can simplify the management and operation of optical networks.
Here is a summary of everything you need to know about OTNs:
- – OTN standardized by ITU as G709 and G798
- – its a telecom transmission protocol for ultra high capacity traffic.
- – its called digital wrapper , because it transport transparently any client traffic in to OTN container.
- – OTN can transport Alot of traffic types like Ethernet , IP , SDH , sonet ,..
- – it allow multiplex , transport , switch and protect high capacity traffic in optical networks
- – there are 3 main electrical layers in OTN frame ( OPU , ODU , OTU )
- – client signals encapsulated in to OPU , then to ODU then to OTU after adding the needed overheads
- – needed overheads like frame alignment signals , mangment overhead , Tandem connection bytes , fault location bytes , performance monitoring bytes ,..
- – optical layers overhead are ( OCH , OMS , OTS ) should be added
- – OTN frame has fixed length 4 rows * 4080 columns
- – OTN frame has variable time duration based on types
- – OTN frame Levels ( OTU 1 , 2 , 3 , 4 , 5 ,.. )
- – as OTN frame type increasing , time duration decreasing and capacity / data rate of frame increasing too
- – there is 6 Level of tandem connection monitoring supported by OTN
- – GCC 1 and GCC 2 for frame mangment
- – PM : path monitoring and SM : section monitoring similar to MSOH and RSOH in SDH
- – SAPI and DAPI represent the source and destination nodes identifiers for OTN network
- – capacities more than 800 G can be supported per frame ( OTU c8 as example )
- – shelfs can support 24 Tera bits per seconds in some scenarios
- – multiple applications use OTN globally like data centers and ultra high capacity network nodes
- – vendors deploy OTN like Huawei , Nokia , ciena, infenera , ZTE
