A transparent transmission method for 10000M Ethernet signals in optical transmission network

Abstract

The invention discloses the method that 10 gigabit Ethernet signals are transparently transmitted in light transmitting network. The invention adopts the first asynchronous mapping type to transparently transmit the 10 gigabit Ethernet signals; wherein the establishment of the first asynchronous mapping type comprises the following steps: (A1): the retention value of any payload structure identification is adopted; the first asynchronous mapping type is designated; (A2): a light channel transmitting unit framing of the first asynchronous mapping type is established; in the byte regulated and controlled by the light channel transmitting unit framing, at least three bits are adopted to pre-define the filling state of the positive and negative adjustment byte; furthermore, one negative adjustment byte is additionally provided in light channel payload unit overhead area; one positive adjustment byte is additionally provided in payload structure; (A3): reference clock is adopted; the lightchannel transmitting unit framing of super frequency is established; the frequency of the light channel transmitting unit framing is 11.0491Gbit / splus and minus20ppm. With the proposal, the inventioncan transparently transmit integral 10GELAN signals in the light transmitting network by the method of asynchronous mapping and totally adapts the frequency deviation of client signals.

Description

technical field [0001] The present invention relates to the transmission of Ethernet services through an Optical Transport Network (OTN), and in particular to a 10 Gigabit Ethernet (10GELAN, ie 10GE LAN, also known as 10GE Ethernet) signal, which is transmitted on the optical channel of the Optical Transport Network The method of transparent transmission in the OPU2 payload area of ​​the transmission unit. Background technique [0002] Optical Transport Network (OTN, Optical Transport Network) is an optical transport specification formulated by ITU-T. It is mainly composed of OPUk (optical channel payload unit, optical channel payload unit), ODUk (optical channel data unit, optical channel data unit) and OTUk (optical channel transport unit, optical channel transmission unit) and other packaging components, where k =1, 2 or 3, representing different rate levels. These three OTU rates correspond to their respective ODU and OPU rates. The details are detailed in ITU-T’s G.709...

AI Technical Summary

Problems solved by technology

Considering that OPUk itself has a frequency difference of 20PPM, the customer signal that can be tolerated is ±45ppm, while the frequency deviation of 10GELAN services is up to ±100ppm, so asynchronous mapping cannot be performed

[0014] If synchronous mapping is used, that is, the OPU2 clock is locked to 10GELAN services, the frequency offset problem can be ignored, but the scalability is relatively poor, and it can only be used for point-to-point connections, or asynchronous crossover at intermediate nodes, and cannot support synchronous crossover

Therefore, this adapted rate cannot enter the crossover network for synchronous crossover, because the synchronous crossover network requires the same ODU clock, and the ODU clock for synchronous mapping comes from 10GELAN, and these 10GELANs are often heterogeneous

[0015] For the bit-agnostic (Agnostic) CBR mapping method, although the undefined overhead byte can be used to indicate the actual transmission byte, which can better adapt to the frequency difference problem, it cannot indicate the specific position of the filling byte, and cannot be used in the payload. Evenly distribute stuffing bytes in the area, so a larger buffer area is needed to accommodate the maximum frequency difference between 10GELAN and OPU2 payload area

[0016] In addition, since the number of bytes in the OPU2 payload area is 3808×4=15232 bytes, about 13 bits are needed to indicate its filling status. When there are other cascade applications, more bits are needed, which requires more OPU overhead bits

Different application scenarios require different overhead bytes for monitoring and management; for example, in the case of virtual concatenation, three overheads in columns 1, 2, and 3 of column 15 in the OTU frame structure are required for indication. Mapping methods with more OPU overhead are also unacceptable

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