32 CHL DWDM

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Transcript of 32 CHL DWDM

32 CHANNEL DWDM SYSTEMZTE

OPTICAL NETWORK ELEMENTST P T P

OA

OAD M

OXC

TP (Transponder) OMUX (Multiplexer) ODEMUX (De-multiplexers) Optical amplifiers OADM OXC

DWDM Components 1 850/1310 15xx 2 3 1...n

Transponder Optical Multiplexer

1 2 3 1...n

1 2 3

Optical De-multiplexer Optical Add/Drop Multiplexer (OADM)

More DWDM Components

Optical Amplifier (EDFA)

Optical Attenuator Variable Optical Attenuator

Dispersion Compensator (DCM / DCU)

Functional block diagram of the ZXWM M900

ZXWM M900 Divided into the hardware system and NM software system, which are independent of each other and work coordinately. Working wavelength range and channel interval C-band (192.1THz ~ 195.2THz) at 100 GHz interval.

System composition OTM: Optical terminal equipment As shown in Fig. OTU stands for the optical transfer board, OMU and ODU for the OM board and the OD board. OBA and OPA for the optical amplifying boards. OSCT for the supervisory board, and it is used as the OSC terminal (OSCT) when using as the terminal. At the receiving end of the OTM, DCM should be added for dispersion compensation after long distance transmission. Wavelength interval transferred by OTU is 100 GHz.

OLA: It is an optical line amplifier OLA: It is an optical line amplifier, including OLA and OSCL. As shown in Fig. OLA stands for the optical amplifying board, OSCL for the supervisory board. When it is used for a line amplifier, there are two supervisory directions, indicated as line OSC (OSCL).

Erbium Doped Fiber AmplifierIsolator Coupler Coupler Erbium-Doped Fiber (1050m) Pump Laser Pump Laser Isolator

Two basic types of amplifiers: Co-directional (pumping) and Counterdirectional. Co-directional pumping results in good SNR performance (preamp), where as Counter-directional results in better gain performance (Post/Power amp). One amplifier does not necessary fit all applications!, especially in LH networks.

EDFA Schematic... ...Optical Isolator

WDM Coupler

EDF

EDF

WDM Coupler OpticalFilter

Optical Isolator

DCF980 Pump Laser 1480 Pump Laser

EDFAs amplify all s in 1550 window simultaneously Key performance parameters include

Saturation output power, noise figure, gain flatness/passband

Wayside Optical Add/Drop Multiplexer1 2

TM

WDM MUXO A

WDM DEMUXO A

TM

15

16

1-4

5-8

Optical Add/Drop MultiplexingTerminal Equipt In-Line Amplifier Terminal Equipt

fixed OADM: : fixed OADM 2 2

1

2

2 1

2 1

2

1

Configurable Configurable OADM : : OADM or 2 1 1 or 2

1OADM : Optical Add/Drop Multiplexer

2

2

2

2

1

OADM ConnectivityOmnibus

From terminal to OADM, or from OADM to OADM

OPTICAL ADD DROP MUX

D

M

COUPLER CIRCULATOR

OPTICAL ADD DROP MUX OADM: It is an optical add/drop multiplexer. OAD stands for the add/drop board, OUT for the optical transfer board, OSCL for the supervisory board. When it is used as an OAM, there are two supervisory directions, indicated as line OSC (OSCL).

Equipment Cabinet Unified Cabinet for ZTE Transmission Equipment Cabinet Structure .Table: Dimensions and Weight of the ZXWM M900 Structure(The weight refers to that of an empty cabinet )

2,000 mm (H) x 600 mm (W) x 300 mm (D) Dimensions x 600 mm (W) x 300 mm (D) 2,200 mm (H) 2,600 mm (H) x 600 mm (W) x 300 mm (D)

Weight (kg) 70 80 90

Optical Terminal Equipment (OTM) The main rack is configured with a NCP and others are extension racks. The main rack consists of 1 power alarm subrack, multiple OTU subracks, 1 OA subrack (equipped with an NCP), 1 ODF plug-in box. An extension rack consists of 1 power alarm subrack, multiple OTU subracks, 1 ODF plug-in box

Optical Line Amplifier (OLA) Generally single-rack configuration. An OLA consists of 1 power alarm subrack, 1 OA subrack. Specific configuration depends on actual conditions.

Optical Add/Drop Multiplexer (OADM) Generally single-rack configuration. An OADM consists of 1 power alarm subrack 1 or 2 OTU subracks 1 OA subrack 1 ODF plug-in box

Layout of Integrated Equipment 2.2m-/2.6m-high cabinet: 1 power alarm subrack, 3 subracks (2 OTU subracks and 1 OA subrack, or 3 OTU subrack), 1 ODF plug-in box. 2m-high cabinet: 1 power alarm subrack, 2 subracks (1 OTU subrack and 1 OA subrack, or 2 OTU subrack), 1 ODF plug-in box

OA Subrack Structure An OA subrack has simple mechanical structure and consists of front/rear aluminum beams, left/right side boards, and guide rail bar. The guide rail (Dimensions: 577 mm (H) * 482.6 mm (W) * 269.5 mm (D)) of a plug-in box is of section aluminum. Backplane: A backplane is the carrier connecting boards and provides the interface between the ZXWM M900 and external signals.

At the upper part of the backplane providing signal connection interfaces like the subrack power socket, network interface, transparent user channel interface, alarm input/output interface . The lower part of the backplane signal sockets and power sockets of various slot boards. Signal sockets at various slots employs the differential data bus to receive/transmit data. They work in parallel to transmit & receive data to the public interface area.

Board insertion area

The board insertion area includes 14 groups of guide rail slots with 30 mm in between

Fan insertion area

Telephone bracket; Located in the front of the backplane interface area and configured within an OA subrack alone to lay a orderwire phone. Air filter; At the lowest part of a subrack. The air filter, together with a fan plug-in box, forms a circulating system within subrack. Chute;Located at the lower part of a subrack and used to lay the fiber coming into and out of a board panel. Installation lug;Including left and right lugs, used to fix a subrack and a cabinet by means of captive screws.

Board Name NCP OSC OHP LAC OA OP OPM OTUF GEMF OAD OMU ODU PWB PWSB FCB

Full Name Net Control Processor Optical Supervisory Channel Orderwire Overhead processor Line Attenuation Compensator Optical Amplifier Optical Protect Board Optical Performance Monitor Optical Transponder Unit withFEC Two Gigabit Ethernet Mux Board with FEC Optical Add/Drop Board Optical Multiplexing Unit Optical De-Multiplexing Unit Power Board Power Supervision Board Fan-Control Board

EquipComponents OA sub rack

OA/OTU subrack

Power Alm subrack

Fan plug-in box

OTUF Implements wavelength conversion of multiple service signals at single-Double-channel 2.5Gbit/s or lower rate. Support doublechannel wavelength conversion. The OTUF on the customer side supports multiple service signals like STM-1/4/16. Optical signals on the line side satisfy G692 requirements. A OTUF has the FEC function conformable to G709 specifications. A OTUF is capable of Bl, B2, and JO detection of SDH signals, and monitor OTU overhead like BiP8,TTI,OTUl-LOF. An OTUF consists of the optical receiver module, optical transmitter module, FEC framer, and control & communication unit.

Multiplexer / Demultiplexer

DWDM Mux

DWDM Demux

Wavelength Multiplexed Signals Wavelengths Converted via Transponders

Wavelength Multiplexed Signals Wavelengths separated into individual ITU Specific lambdas

Loss of power for each Lambda

OMU optical multiplexer OMU multiplexes optical signals with different wavelengths into a fiber. Before combined output, OMU sends some light to the optical power monitoring module, which provides an online monitoring interface and reports to the NMS the total optical power output by means of the control & communication unit.

ODUOptical De-Multiplexing Unit ODU is capable of de-multiplexing and provides an online monitoring interface for combined light. By means of an optical demultiplexer, ODU filters optical signals of various channels combined in a fiber and sends them to different receivers. Before they enter the optical demultiplexer, some light is sent to the optical power monitoring module, which provides an online monitoring interface and reports total optical power input to the NMS by means of the control & communication unit.

OAD Optical Add/Drop Board An OAD invariably adds/drops 4-channel signals(Specific wavelength of add/drop signals is customized as required by the user) with constant wavelength. Other wavelength signals and locally added signals are multiplexed and output. Monitor add/drop optical signal power. OAD consists of the OADM, power monitoring unit, and control & communication unit.

LAC Line Attenuation Compensator According to line optical power detection, adjust the Electrical Variable Optical Attenuator (EVOA) in LAC by means of the NMS to ensure the power points of various segments during the running. The receiving power and OSNRof the receiving end maintain their normal value. LAC includes 2 types: LACG and LACT. LACG has 2 EVOAs applicable to OLA, OADM, and back-to-back OTM site. LACT has 1 EVOA applicable to a single-end OTM site.

OA Optical Amplifier The OA uses EDFA to amplify optical signals. It substitutes the original electrical regenerator relay mode to save system costs and simplify the system. According to its functions and locations in the system, OA includes 3 types: Optical Booster Amplifier (OBA), Optical Line Amplifier (OLA), and Optical Pre Amplifier (OPA). The OA is capable of gain adjustment, gain locking, and power suppression & control, thus realizing power adjustment.

OA Optical Amplifier Capable of Automatic Power Shut Down (APSD)/Automatic Power Reduction (APR) and restarting. APSD, APR, and restart functions mean that when detecting any input no light (that is, fiber cut) in a link, the system is capable of shutting down or reducing the output optical power of an upstream amplifier or all amplifiers within a downstream regenerator section. When signals are recovered, the OA resumes its operation. This ensures that optical power levels satisfy safety requirements during line fiber correction

OA Optical Amplifier

A board is equipped with a 1510/1550 optical multiplexer and optical demultiplexer (OBA has an optical multiplexer alone and OPA has an optical monitoring module located at the input & output end provides an online monitoring interface without affecting any service. EDFA, EDFA drive circuits: EDFA amplifies 1550 nm optical signals and is controlled by an EDFA drive circuit. The EDFA drive circuit is capable of gain adjustment, power suppression, gain locking. Control & communication: Used to detect input/output optical power and report it to the NMS. Meanwhile, the control & communication receives the control commands sent from the NMS to a board. The adjustable range of gain adjustment commands is the gain nominal value of 2 dB and the adjustment step length of 0.1 dB.

Loss Management: Limitations Erbium Doped Fiber AmplifierNoise Figure > 3 dB Typically between 4 and 6

Each EDFA at the Output Cuts at Least in a Half (3dB) the OSNR Received at the Input

Each amplifier adds noise, thus the optical SNR decreases gradually along the chain; we can have only have a finite number of amplifiers and spans and eventually electrical regeneration will be necessary Gain flatness is another key parameter mainly for long amplifier chains

Optical Signal-to Noise Ratio (OSNR)

Signal Level

X dB

Noise Level

Depends on : Optical Amplifier Noise Figure:(OSNR)in = (OSNR)out NF(OSNR)in

EDFA Schematic (OSNR)out Pin

NF

Target : Large Value for X OSNR>25 dB

OPM Optical Performance Monitor It monitors optical performance in optical channels. Besides, it measures the parameters of each optical channel, such as optical power, central wavelength, and OSNR, and reports relevant data to the NMS. Precision of the power measurement: 1.0 dB. Precision of the central wavelength measurement: 0.1 nm. Precision of the OSNR measurement: 1.5 dB (OSNR>25 dB). Each OPM detects the performance of 4 optical interfaces. OPM is accessed to 4 optical interfaces. In the detection processing module, it measures the parameters of each optical channel and reports them to the NMS by means of the control & communication module. The NMS may also deliver query commands of optical channel parameters by means of the control & communication module.

ITU-T BAND ALLOCATIONOptical Supervisory channel

C BANDBLUE BAND1530

L BANDRED BAND

1500

1520

1542 1547

1560

1620

C BAND PRODUCTS ARE COMMERCIALLY AVAILABLE. ERBIUM DOPED FIBRE AMPLIFIERS SUITABLE FOR C BAND. GAIN IN RED BAND FLATTEST FOR EDFA. SOME MANUFACTURERS PROVIDE 16 CHANNELS IN RED BAND ONLY. OTHERS USE BOTH RED & BLUE BANDS.

OSC Optical Supervision Channel OSC forwards the supervisory information carried in a supervision channel (1,510 nm) to an NCP and OHP. Meanwhile, it completes reverse conversion. According to different demands, OSC includes 2 types: Optical Supervision Channel of Terminal (OSCT) and Optical Supervision Channel of Line (OSCL). OSCT: Used to process supervisory signals of 2 directions, applicable to an OTM equipment. OSCL: Used to process supervision signals of 4 directions. It is applicable to both OLA equipment and OADM equipment.

OHP (Order-wire Overhead processor ) Responsible for processing orderwire overhead of in a supervisory channel, and processing voice and signaling related to voice processing. Order wire liaison system in the following calling modes: Addressing calling mode. No. less than 99 sites are selected. Conference calling mode: 3 sites. Group address calling mode Broadcast calling mode

NCP Net Control Processor NCP performs all the functions of an NE monitoring subsystem which include: NCP collects and processes the alarm and performance inform...ion of an NE where NCP is located, and reports it to the NMS. Meanwhile, NCP forwards data from other NCPs and receives the control commands from the NMS. Capable of saving configuration data. NCP works independently of the-NMS as soon as initial configuration is completed. NCP needs to provide F, f, and Qx interfaces to an upper-layer management system, ECC route to communicate with other NEs, S interface to communicate with MCU of boards. The Qx interface and the F interface adopt 10/100M Ethernet electrical interface; the f interface adopts the RS-232 interface and conforms to the V.28 protocol.

Net Control Processor Capable of alarm input/output. Alarm input function: Provides 4-channel alarm input, including the open-door alarm, fire alarm, flood alarm, and temperature alarm. Alarm output function: Including the LED alarm and sound alarm. Provides multirack management function. An NCP manages 4 racks at most and can be flexibly configured according to the number of racks in an node.