4_optix osn 380068008800 protection issue1.05

OptiX OSN 3800/6800/8800 Protection

1. System Overview... .............Page 4

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Confidential Information of Huawei. No Spreading Without Permission

2. Optical layer protection ...Page 9

3. Electrical layer protection .........Page 25

OptiX OSN 3800/6800/8800 Protection P-1



Referece

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ITU-T G.709

ITU-T G.798

OptiX OSN 8800 /6800/3800 Feature Description


The system performs distributed power supply and integrated protection upon the

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secondary power of all units except that of the XCS.

The system control and communication (AUX / SCC) board contains power backup unit

(PBU) and can provide 1:N power backup for the system. The system uses the SCC board

to provide integrated power protection and secondary power backup upon the +3.3 V

power supply of all units in every subrack except that of the XCS.

When the system detects a power fault (over voltage or under voltage ) in units other than

the XCS, the PBU begins to supply power within 600s to ensure that the board works

normally.

OptiX OSN 3800PIU/APIU house 6, 7 slot. OptiX OSN 6800PIU house 19, 20 slot. OptiX OSN 8800PIU house

OptiX 8800 T64 General: IU69 & IU78IU70 & IU79IU80 & IU88IU81 &IU89 OptiX 8800 T64 Enhanced: IU69 & IU89IU70 & IU88IU78 & IU81IU79

&IU80

OptiX 8800 T32: IU39 & IU45IU40 & IU46 OptiX 8800 T16: IU20 & IU23


The slots of XCS of OSN 6800 are 9&10. In default, slot9 is active, slot10 is standby.

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The slots of SCC of OSN 6800 are 17&18. In default, slot18 is active, slot17 is standby.


The slots of XCH of OSN 8800 are 9&10. In default, slot9 is active, slot10 is standby.

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The slots of SCC of OSN 8800 are 11&28. In default, slot28 is active, slot11 is standby.


The OLP aims to protect fibers of the line, which adopts the dual feeding and selective

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receiving function of the OLP board. This kind of protection is performed between two

sites segmentally for the optical signal that is multiplexed. This makes that the working

path and the protection path of the protected site must adopt the diverse route.

We suppose that the OLP is configured between A and B, B and C, C and D

respectively. Then when the fiber between A and B is broken, the OLP switching is

triggered only between the A and B. At the same time, the OLP switching is not

triggered between the downstream sites: B and C, and C and D. Hence, we think

that the OLP protection is performed segmentally.

For the ring networking, as services between sites can be protected through the

diverse route of the ring network itself, the OLP is not used.


In this figure, we can see that the OLP board consists of a splitter and an optical switch.

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The square in this figure represents the splitter, and the circle represents the optical switch.

In the transmit direction of the service, the multiplexed signal is accessed to the

splitter from the TI optical interface, dually fed from the splitter to the TO1 and

TO2 optical interfaces respectively, and output to the active optical channel

through the TO1 and to the standby optical channel through the TO2. In this figure,

the line in blue represents the active route, and the line in red the standby route

In the receive direction of the service, two same multiplexed signals are received

from the active and standby lines, and output to the corresponding RI1 and RI2

optical input interfaces. Then the optical switch detects the optical power of the

two signals from the active and standby channels and controls the protection

switching of the active and standby channels based on it.


After we have an analysis on the OLP switching and recovering, we conclude that the OLP has the

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following features:

The OLP performs the switching at the receive end, and is defaulted as non-revertible. It can

be configured using the NM system.

As the OLP switching does not require the APS protocol, it is simple and reliable.

In addition to those features, we need to note that:

The OLP board is required to be configured with the protection group before working.

Different protection groups report different PS switching alarms.

NG-WDM provides the OLP and DCP boards. The DCP board is equivalent to two OLP

boards, and is aimed to enhance the board integrity. However, for the optical line

protection, the DCP is not required to use, as it may affect service in several directions upon

the board failure. Hence, the DCP board is mainly applied to the 1+1 protection at the

client-side of the OTU instead of the optical line protection.

In the actual application, due to the features of the OLP, it can also be applied to the OTU

intra-board 1+1 protection, OTU client-side 1+1 protection as well as the optical line

protection. In the next chapters, we will further explain it.


The active and standby channel difference" refers to the received power difference

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between the active and standby optical channels. The active and standby channel

difference threshold refers to the threshold of the received power difference range

between the active and standby optical channels.

On the engineering site, the quality and situation of the active and standby optical

channels cannot be guaranteed to be totally the same. Some difference is allowed and

reasonable. Hence, the NG-WDM provides the initial difference of the active and standby

channels that can be set to eliminate the difference of the engineering design. This

difference is called active and standby channel difference threshold, which can be set

using the NM system.

The threshold can be changed from 3 to 8 dB.

Initial power difference be changed from -10 to 10 dB.


As shown in this figure, services between A and C are dually fed and selectively received

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on the OTU board. The working service and protection service of this wavelength arrives at

the sink site through different routes of the ring network. This can protect services.

As for the ring networking, the OTU intra-board 1+1 protection uses the separated paths

in the ring to perform the protection, that is, services are transmitted in both the positive

and opposite direction of the ring before arriving at the destination node.

As for the chain networking, it is much similar to the optical line protection explained in

chapter one in that the diverse route is required to provide between the adjacent sites. We

need to note that in the actual configuration, line fibers of the OTU board that are dually

fed are sent to the eastward and westward lines of the node through different equipment

types: MUX/DMUX and OA. This process is omitted in this figure.


For the 2.5G OTU board, two board types are provided currently, for example, the LDGS

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and the LDGD. The LDGD itself has the function of dual feeding and selective receiving.

The working principle is that the board integrates an optical transmit module and a splitter

for dual feeding, and two optical receive modules and corresponding O/E conversion

circuits for selective receiving at the electrical layer.

For the 5G,10G&40G OTU, as the space is limited due to the board layout, it cannot

integrate the devices for the dual feeding and selective receiving. Hence, for achieving the

function of the dual feeding and selective and receiving, the external OLP is required.

As the 2.5G board detects the signal at the electrical layer, it can perform the switching

based on the actual situation of services in the active and standby channels, for example,

the LOF and BIP8 bit error. And in the OLP mode, whether the switching is trigged is

decided by the optical power, that is, the LOS or over low optical power.


The recovering of the OTU intra-board 1+1 protection switching is defaulted as non-

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revertible. That is, when the damaged channel recovers, services are not switched over to

the original active channel.


In the case of the intra-board 1+1 protection configured by using the OLP or DCP

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board,when the Monitoring Channel is configured, the Revertive Mode can be set to

only the Non-Revertive mode.

For the L4G, the client-side port attributes of corresponding channels of the working and

protection boards must be the same. Otherwise, the services are not available.

The attribute settings of client-side services in the main path and those in the standby path

must be the same. Otherwise, the services are not available.


The client-side 1+1 protection of the OTU uses the dual feeding and the selective receiving function

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of the OLP/SCS board to protect the OTU board and units after it.

The client-side 1+1 protection performs the switching based on the client-side ports. And it has the

larger extent of protection that other protection types.

We can see from this figure that the client-side 1+1 protection of the OTU actually has two

configurations. One does not require using the centralize cross-connection and the other requires

using it.

the software can perform the switching at different granularities based on the effect of the fault.

When the line fiber is damaged, the switching is performed for the entire board. In this case, it is

the same with that of the OTU intra-board 1+1 protection in effect. When the certain channel of

client-side fiber is broken, perform the switching on the client-side optical port that is affected.

In the master/slave mode, when the active and standby OTUs are in the same subrack, the OLP and

SCS can be used; when the active and standby OTUs are not in the same subrack or in the same NE,

only the OLP can be used. When the active and standby OTUs are not in the same subrack, the NE

software cannot judge the subrack power-off and communication failure between subracks. The

former one requires the switching and the latter one does not. Hence, when the OTU is applied in

the subrack, it is necessary to use the OLP because this can have the OLP switching triggered when

there is no optical signal due to the power-off.


The ODUk SNCP protection utilizes the dual fed and selective receiving function of the

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crossconnections at the electrical layer to protect the line board and OCh fiber.

For the OptiX OSN 8800, The granularity is ODU0, ODU1, ODU2, ODU3, or ODU4 service.

For the OptiX OSN 6800, the granularity is ODU1 or ODU2 service.

For the OptiX OSN 3800, the granularity is ODU1 service.


In the transmit direction, the client services to be protected are input through the tributary

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board. They are split into working signals and protection signals after passing through the

XCS board or mess cross-connections. The working signals and the protection signals are

respectively transmitted in the working channel and the protection channel.

In the receive direction, in normal cases, only the cross connection corresponding to the

working line board is enabled and that to the protection line board is disconnected. When

the working channel is faulty, the cross connection corresponding to the working line

board is disconnected and that to the protection line board is enabled. The service signals

are transmitted in the protection channel.

After the working channel returns to normal, the service signals can be switched back to

the cross connection corresponding to the given line board according to the existing

configuration in the NM system.

Tributary SNCP uses the dual fed and selective receiving function of the electrical layer

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cross-connections to protect SDH/SONET or OTN services received on the client side.

In the case of ODUk tributary SNCP protection, only OTN services or SDH/SONET services

at the STM-16/OC-48 rate or higher rate are supported; the GE, 10GE LAN, and 10GE

WAN services are not supported.

For the OptiX OSN 8800, the cross-connect granularity is ODU0, ODU1, ODU2, ODU3, or

ODU4 service.

For the OptiX OSN 6800, the cross-connect granularity is ODU1 or ODU2 service.

For the OptiX OSN 3800, the cross-connect granularity is ODU1 service.


The supported protection types vary with the type of the services accessed by the tributary


board:

When the tributary board accesses the OTN services, the SNC/I, SNC/N, and SNC/S

are supported.

When the tributary board accesses the STM-16 or OC-48 SDH service or SDH or

SONET services of a higher level, only the SNC/I is supported.


The ODUk SPRing protection mainly applies to the ring network with distributed services.

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This protection uses two different wavelengths to achieve the protection of multiple

distributed services between all stations.


General node

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After the ODUk SPRing protection is configured at a general node, the pass

through cross connection of the protection channel is automatically generated

Management node

If all protection channels of the ring network are pass through cross-connections,

their performance cannot be accurately detected. In this case, the protection fails.

Hence, a management node must be specified. After the management node is

specified, the system automatically deletes the bidirectional cross-connection

between the east and west protection channels of the protection group that

corresponds to the management node. In the mean time, the system tri-fed one of

the add/drop services at the node. One of the three channels of trisected services is

fed to the normal working channel; the other two of the three channels of

trisected services are respectively broadcasted to the west and east protection

channels.


In the transmit direction: The client services to be protected are input through the tributary

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board, cross-connected to the east working line board, and then dually fed to the east and

west protection line boards. In this way, the working signals and protection signals are

separated. After that, the working signals and protection signals are respectively

transmitted over the working and protection channels.

In the receive direction, when the operating is normal, only the cross-connection of the

working channel is enabled; that of the protection channel is disabled. When the working

channel is faulty, disconnect the cross-connection of the working channel at the receive

end. Hence, the cross-connection of the protection channel that corresponds to the west

line board is available, and the services are operating in the protection channel.

When the working channel is restored, because the protection is revertive, the service

signals are switched back the cross-connection that corresponds to the originally specified

line board.

TU: Tributary unit, such as TDG, TQS...

LU: Line unit, such as NS2, ND2...


In normal situation, the protection ODUk just received by NS2, TU will not receive it..

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Bridge means dual sending.

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Switch means selective receiving.

Trigger conditions:

Board not in position.

SF:

R_LOS,R_LOC,HARD_BAD,OTU2_LOF,OTU2_AIS,OTU2_LOM,ODU1_LOFLOM,ODU

1_TCM6_AIS,ODU1_TCM6_OCI,ODU1_TCM6_LCK.

SD: ODU1_TCM6_DEG,ODU1_TCM6_EXC,OTU2_DEG,OTU2_EXC.


Bridge means dual sending.

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Switch means selective receiving.

Trigger conditions:

Board not in position.

SF:

R_LOS,R_LOC,HARD_BAD,OTU2_LOF,OTU2_AIS,OTU2_LOM,ODU1_LOFLOM,ODU

1_TCM6_AIS,ODU1_TCM6_OCI,ODU1_TCM6_LCK.

SD: ODU1_TCM6_DEG,ODU1_TCM6_EXC,OTU2_DEG,OTU2_EXC.


WTR: 512m, default value: 10mins.

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Course Name P-47


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