GB/T 51152-2015Code for engineering design of wavelength division multiplexing (WDM) optical fiber transmission systems (English PDF)

2.1 Terminology

2.1.1 C-band conventional band

The C band refers to the band with a wavelength between 1530nm and 1565nm.

2.1.2 L-band long wavelength band

The L band refers to the band with a wavelength between 1565nm and 1625nm.

2.1.3 Optical channel

The channel for unidirectional transmission of optical signals in the optical multiplexing section.

2.1.4 Nominal central frequency (wavelength) nominal central frequency (wavelength)

Taking the frequency 193.10THz (vacuum wavelength 1552.52nm) as the reference frequency (wavelength), the frequency (wavelength) allocated at certain frequency intervals in the wavelength division multiplexing system.

2.1.5 Optical path

All facilities and means for transmitting specific service signals between the client interface of the source point and the sink point wavelength division multiplexing equipment.

2.1.6 Optical booster amplifier

It is used behind the multiplexer at the sending end of the wavelength division multiplexing system to increase the optical power of the system.

2.1.7 Optical pre-amplifier optical pre-amplifier

It is an optical amplifier used in front of the demultiplexer at the receiving end of the wavelength division multiplexing system to improve the sensitivity of signal reception.

2.1.8 Optical line amplifier optical line amplifier

An optical amplifier used to extend the distance of non-electric repeaters to supplement fiber loss between passive fiber segments.

2.1.9 Optical amplifier span

Refers to adjacent optical amplifier stations (OLA stations), between optical terminal stations (OTM stations) and adjacent optical amplifier stations (OLA stations), and between optical splitter stations (OADM stations) and adjacent optical amplifier stations (OLA stations), forming a transmission segment for extending the length of the non-electric relay.

2.1.10 Optical multiplex section optical multiplex section

Refers to adjacent optical terminal stations (OTM stations), between optical branch stations (OADM stations), and between optical terminal stations (OTM stations) and adjacent optical branch stations (OADM stations), forming a relay with electrical regeneration The transfer section of the function.

2.1.11 Raman amplifier raman amplifier

An optical amplifier that amplifies signals based on the Stimulated Raman Scattering (SRS) effect of transmission fibers in wavelength division multiplexing systems.

2.1.12 (optical) coherent reception (optical) coherent detection in the receiving device, the local optical carrier and the same-frequency optical carrier signal are used for coherent mixing, and the phase information of the carrier signal is detected and received.

2.1.13 Ultra-long-haul DWDM sys-tem

Multi-span section with target distance greater than 1000km and single-span section 40/80×10G DWDM system with target distance greater than 160km.

2.1.14 Receiver optical signal noise ratio tolerance receiver optical signal noise ratio tolerance

In a wavelength division multiplexing system, when the maximum bit error rate (such as 1×10-12) is reached after the error correction of the reference receiver, the optical wavelength converter (OTU) is directly connected to the reference receiver Sn (or Rn) point The minimum tolerable OSNR value.

2.2 Abbreviations

ALS (Automatic Laser Shutdown) automatic laser shutdown APR (Automatic Power Reduction) Automatic optical power reduction ASON (Automatically Switched Optical Network) automatic switching optical network BBER (Background Block Error Ratio) background block error ratio BOL(Begin Of Life) BTB(Back-To-Back) back to back CMI (Coded Mark Inversion) mark reverse coding CORBA (Common Object Request Broker Architecture) public object request broker system CWDM (Coarse Wavelength Division Multiplexing) Coarse Wavelength Division Multiplexing DCM(Dispersion Compensation Module) Dispersion Compensation Module DCN (Data Communication Network) data communication network DGD (Differential Group Delay) differential group delay DWDM (Dense Wavelength Division Multiplexing) dense wavelength division multiplexing DP-QPSK (Dual Polarization Quadrature Phase Shift Keying) Dual Polarization Quadrature Phase Shift Keying RZ-DQPSK (Return to Zero Differential Quadrature Phase Shift Keying) Return to Zero Differential Quadrature Phase Shift Keying EMS (Element Management System) network element management system EOL (End Of Life) end of life FEC (Forward Error Correction) forward error correction HRP (Hypothetical Reference Path) Hypothetical Reference Path LAN (Local Area Network) local area network LCT (Local Craft Terminal) local maintenance terminal MPI (Main Path Interface) main optical channel interface NMS (Network-level Management System) Network (level) management system NRZ (Non-Return to Zero) non-return to zero (code) OA(Optical Amplifier) optical amplifier OADM (Optical Add-Drop Multiplexer) Optical Add-Drop Multiplexer OCHP (Optical Channel Protection) optical channel protection ODB (Optical Duobinary) optical duobinary code ODF(Optical Distribution Frame) Optical Distribution Frame OD(U)[Optical De-multiplexer(Unit)] Optical demultiplexer (demultiplexer) device (unit) ODUk (Optical Channel Data Unit-k) optical channel data unit k OLA (Optical Line Amplifier) Optical Line Amplifier OLP (Optical Line Protection) optical line protection OM(U)[Optical Multiplexer(Unit)] Optical multiplexer (multiplexer) device (unit) OMSP (Optical Multiplex Section Protection) optical multiplex section protection OSC (Optical Supervisory Channel) Optical Supervisory Channel OSNR (Optical Signal-to-Noise Ratio) Optical Signal-to-Noise Ratio OTM (Optical Terminal Multiplexer) optical terminal multiplexer OTN (Optical Transport Network) Optical Transport Network OTU (Optical Transponder Unit) optical conversion unit (wavelength converter) OTUk (Optical Channel Transport Unit-k) Optical Channel Transport Unit k P-DPSK (Partial Differential Phase Shift Keying) partial differential phase shift keying PMD(Polarization Mode Dispersion) Polarization Mode Dispersion PSBT (Phase-Shaped Binary Transmission) phase shaping binary transmission (R) OADM [(Reconfigurable) Optical Add/Drop Multiplexer] (Reconfigurable) Optical Add-Drop Multiplexer RZ (Return to Zero) return to zero (code) RZ-AMI (Return-to-Zero Alternate Mark Inversion) return-to-zero signal flipped alternately SDH (Synchronous Digital Hierarchy) synchronous digital system SESR (Severely Errored Second Ratio) Severely Errored Second Ratio SNMS (Sub-network Management System) subnetwork management system STM (Synchronous Transport Module) synchronous transmission module WAN (Wide Area Network) wide area network WDM (Wavelength Division Multiplexing) wavelength division multiplexing

3.1 Characteristics of WDM system

3.1.1 Wavelength division multiplexing (WDM) system shall be divided into dense wavelength division multiplexing (DWDM) system and coarse wavelength division multiplexing (CWDM) system. The channel interval of the DWDM system should be 0.4nm or 0.8nm, and the number of optical channels in the 1530nm~1565nm band can be 40 channels or 80 channels; the channel interval of the CWDM system should be 20nm, and the number of optical channels in the 1270nm~1610nm band can be 4-way, 8-way or 16-way.

3.1.2 The customer interface types supported by the WDM system shall comply with the provisions in Table 3.1.2.

Table 3.1.2 Customer interface types supported by WDM system

3.1.3 The path type and path rate of the WDM system shall comply with the provisions in Table 3.1.3.

Table 3.1.3 Channel type and channel rate of WDM system

3.2 System Composition

3.2.1 The wavelength division multiplexing system (Figure 3.2.1) shall consist of optical terminal multiplexing equipment, optical line amplification equipment and optical add-drop multiplexing equipment, and shall meet the following requirements.

1 Optical terminal multiplexing equipment should include multiplexers, demultiplexers, optical amplifiers, and wavelength conversion units;

2 Optical line amplification equipment shall include optical amplifiers;

3 Optical add-drop multiplexing equipment should include multiplexers, demultiplexers, optical amplifiers, and wavelength conversion units.

Figure 3.2.1 WDM system composition

Tx/Rx-customer equipment; BA-optical power amplifier; PA-optical preamplifier; LA-optical line amplifier

3.3 System Application Classification

3.3.1 The application code of the multi-span DWDM system shall be represented by the character sequence Mn.Bc-xW(-D)-z(S), and the application code of the single-span DWDM system shall be represented by the character sequence Sn.Bc-W(- D)-z(s) indicates that the meaning and value requirements of each character shall comply with the provisions in Table 3.3.1.

Table 3.3.1 Character meanings and value requirements in DWDM system application codes

Note. D is only used for WDM systems with channel type 100G.

3.3.2 The application code of the DWDM system shall comply with the provisions in Table 3.3.2.

Table 3.3.2 Application codes of common DWDM systems

3.3.3 The application code of the CWDM system shall be represented by the character sequence nWx-ytz, and the meaning and value requirements of each character shall comply with the provisions in Table 3.3.3.For single-fiber bidirectional systems, a letter B should be added before the application code. For systems with FEC, the letter F can be added at the end of the code to indicate.

Table 3.3.3 Character meanings and value requirements in CWDM system application codes

3.3.4 The application code of the CWDM system shall comply with the provisions in Table 3.3.4.

Table 3.3.4 Application codes of common CWDM systems

Note. The target distance is used for classification and should be calculated in accordance with Article 4.2.2 of this specification in engineering.

3.3.5 The application code of WDM system engineering should be determined according to factors such as station settings, optical fiber parameters and system capacity.

3.4 Central wavelength allocation

3.4.1 The nominal center wavelength and center frequency of the 32-channel and 40-channel DWDM systems based on the C-band shall comply with the provisions in Table 3.4.1-1.The nominal center wavelength and center frequency of the 80-channel DWDM system based on the C-band The frequency shall comply with the provisions in Table 3.4.1-2.

Table 3.4.1-1 Wavelength allocation scheme of 40-channel DWDM system based on C-band

Note. 1.The 32-wave continuous frequency band DWDM system should use the central wavelengths numbered 9-40, and the 32-wave separated frequency-band DWDM system should use the central wavelengths numbered 1-16 and 25-40;

2 Those marked with * are scalable wavelengths, which can be selected for DWDM systems with 41 to 52 channels.

Table 3.4.1-2 C-band-based 80-channel DWDM system wavelength allocation scheme

Note. The ones marked with * are scalable wavelengths, which can be selected for DWDM systems with 81 to 104 channels.

3.4.2 The nominal central wavelength of the channel of the CWDM system shall comply with the provisions in Table 3.4.2.

Table 3.4.2 CWDM system channel wavelength allocation scheme

Note. * indicates the wavelength used by the 8-channel CWDM system. Other number of channel wavelength options can be selected within the above range.

3.5 Main Optical Channel Interface

3.5.1 The reference point of DWDM optical interface shall adopt the following definition (Figure 3.5.1-1 and Figure 3.5.1-2).

1 The reference point of the optical fiber connection after the output interface of the customer signal transmitter is S, and the reference point of the optical fiber connection before the input interface of the customer signal receiver is R;

2 The reference point of the optical fiber connection after the OTU is connected to the output interface of the OMU is Sn, and the reference point of the optical fiber connection before the OTU input interface is connected to the back of the ODU is Rn;

3 The reference point of the optical fiber connection after the optical output interface of OA (for optical power amplification) at the back of the OMU is MPI-SM, and the reference point of the optical fiber connection before the input interface of OA (for preamplification) at the front of the ODU is MPI-RM;

4 The reference point of the optical fiber connection after the output interface of OA (for line amplification) is SM, and the reference point of the optical fiber connection before the input interface of OA (for line amplification) is RM.

Figure 3.5.1-1 Schematic Diagram of DWDM System Reference Setup

Figure 3.5.1-2 DWDM system (R)OADM reference point setting diagram

3.5.2 DWDM system main optical channel interface parameters, attenuation range, dispersion tolerance, differential group delay (DGD), etc. shall comply with the following regulations.

1.The 32/40×2.5G WDM system shall comply with the current industry standard "Technical Requirements for Optical Wavelength Division Multiplexing System (WDM)—32×2.5Gbit/s Part" YD/T 1060;

2 The 32/40×10G WDM system shall comply with the relevant provisions of the current industry standard "Technical Requirements for Optical Wavelength Division Multiplexing (WDM)—16×10Gb/s, 32×10Gb/s" YD/T 1143;

3 The 80×10G wavelength division multiplexing system shall comply with the relevant provisions of YD/T 1274 of the current industry standard "Technical Requirements for Optical Wavelength Division Multiplexing System (WDM)—160×10Gb/s, 80×10Gb/s Parts";

4 40/80×40G wavelength division multiplexing system should comply with the current industry standard "N×40Gbit/s Optical Wavelength Division Multiplexing (WDM) System Technical Requirements" YD/T.1991;

5 40/80×10G multi-span ultra-long-distance WDM system and 40×10G single-span ultra-long-distance WDM system shall comply with the current industry standard "N×10Gbit/s ultra-long-distance WDM (WDM) System Technical Requirements" YD/T 1960 related regulations;

6 The N×100G wavelength division multiplexing system shall comply with the relevant provisions of the current industry standard "N×100Gbit/s Optical Wavelength Division Multiplexing (WDM) System Technical Requirements" YD/T 2485.

3.5.3 The optical interface parameters of the main optical channel of the CWDM system shall comply with the relevant provisions of the current industry standard "Technical Requirements for Coarse Wavelength Division Multiplexing (CWDM) System" YD/T 1326.

3.5.4 The optical interface parameters of the main optical channel of the wavelength division multiplexing ring network shall comply with the relevant provisions of the current industry standard "Technical Requirements for Wavelength Division Multiplexing (WDM) Ring Networks of Metro Optical Transport Networks" YD/T 1205.

3.6 Optical interface of wavelength converter

3.6.1 In DWDM and CWDM systems, typical OTUs should be divided into transceiver-integrated OTUs (Figure 3.6.1-1), sub-rate multiplexing OTUs (Figure 3.6.1-2) and relay OTUs (Figure 3.6.1-3).

Figure 3.6.1-1 Schematic diagram of OTU with integrated transceiver

Figure 3.6.1-2 Schematic diagram of sub-rate multiplexing OTU

Figure 3.6.1-3 Schematic diagram of relay OTU

3.6.2 The optical interface of the S/R reference point of the wavelength division multiplexing system shall meet the following requirements.

1 The interface parameters of STM-16 and STM-64 shall comply with the relevant provisions of the current national standard "Technical Requirements for Optical Interface of Synchronous Digital System Equipment and Systems" GB/T 20185;

2 The interface parameters of STM-256 shall comply with the relevant provisions of YD/T 2273 of the current industry standard "General Technical Requirements for Synchronous Digital Hierarchy (SDH) STM-256";

3 The interface parameters of OTU1, OTU2 and OTU3 should comply with the relevant provisions of the current industry standard "Optical Transport Network (OTN) Physical Layer Interface" YD/T 1634;

4 The interface parameters of 40GE, 100GE and OTU4 shall comply with the relevant provisions of the current industry standard "N×100Gbit/s Optical Wavelength Division Multiplexing (WDM) System Technical Requirements" YD/T 2485;

5 The interface parameters of GE, 10GE LAN and 10GE WAN shall comply with the relevant provisions of the current industry standard "Technical Requirements for Ethernet Switches" YD/T 1099.

3.6.3 The optical interface parameters and jitter performance of the channel signal of the DWDM system at the Sn/Rn reference point shall comply with the following regulations.

1.The 32/40×2.5G DWDM system shall comply with the current industry standard "Technical Requirements for Optical Wavelength Division Multiplexing (WDM) System—32×2.5Gbit/s Part" YD/T 1060;

2.The 32/40×10G DWDM system shall comply with the current industry standard "Technical Requirements for Optical Wavelength Division Multiplexing System (WDM)—16×10Gb/s, 32×10Gb/s Parts" YD/T 1143;

3.The 80×10G DWDM system shall comply with the current industry standard "Technical Requirements for Optical Wavelength Division Multiplexing System (WDM)—160×10Gb/s, 80×10Gb/s Parts" YD/T 1274;

4.The 40/80×40G DWDM system should comply with the relevant provisions of the current industry standard "N×40Gbit/s Optical Wavelength Division Multiplexing (WDM) System Technical Requirements" YD/T.1991;

5 40/80×10G multi-span ultra-long-distance DWDM system and 40×10G single-span ultra-long-distance wavelength division multiplexing system should comply with the current industry standard "N × 10Gbit/s ultra-long-distance wavelength division multiplexing (WDM) System Technical Requirements" YD/T 1960 related regulations;

6 The 80×100G DWDM system shall comply with the relevant provisions of the current industry standard "N×100Gbit/s Optical Wavelength Division Multiplexing (WDM) System Technical Requirements" YD/T 2485-2013.

3.6.4 The optical interface parameters of the CWDM system channel signal at the Ss/Rs reference point shall comply with the relevant provisions of the current industry standard "Technical Requirements for Coarse Wavelength Division Multiplexing (CWDM) System" YD/T 1326.

3.7 Optical Supervisory Channel

3.7.1 The working wavelength of the DWDM system optical monitoring channel should be 1510nm±10nm/1625nm±10nm, and the signal rate can be selected from STM-1 (155.520Mbit/s), E1 (2Mbit/s), E2 (8Mbit/s) or Ethernet 10Mbit/s, 100Mbit/s or other speeds of the network.

3.7.2 The wavelength of the optical monitoring channel of the CWDM system can be 1310nm or other available wavelengths, and the signal rate of the optical monitoring channel can be 2Mbit/s of CMI code or 10Mbit/s or 100Mbit/s of Ethernet.

3.7.3 The optical monitoring channel shall meet the following requirements.

1 The optical monitoring signal should be able to transmit bidirectionally on the two optical fibers of the single-fiber unidirectional wavelength division multiplexing system.

2 The monitoring path shall not limit the distance of the main path. The OSC should still be available when the optical amplifier fails.

3 The OSC transmission shall be segmented and have 3R and two-way transmission functions. In each WDM node device, the monitoring information should be received correctly, and new monitoring signals can be added.

4 OSC should not be limited to services at 1310nm wavelength.