Problem Description:         <?xml:namespace prefix = "o" ns = "urn:schemas-microsoft-comfficeffice" />

“X” is an operator in BD. In their DWDM backbone layer, there is a link from “A” to “B”. We want to include one new node “C” between this links. So we need to make some adjustments in the optical layer due to changes in link loss. For this link we want to pass through all the OCh on TNELG2 node. Customer requires transferring all the service from existing to new route in one night for each fiber route.

 

Solution:

As per the requirement, we require to do not only include nodes in the existing link but also need to change amplifier board in optical layer in each direction. In general we will follow below steps for the implementing the work

 

New Node preparation:

Two new node will be prepare after integration of the nodes in the EMS and this work will be done much before the operation

 

Existing nodes and service preparation:

Before including node in the existing link, we will prepare node as per optical layer design(i.e:- amplifier board for each link will change as per design of node inclusion).

 

Node Inclusion:

After successfully prepare the new and existing nodes then we will start our migration work and start fiber cut and node inclusion.

Optical Layer Change:

After the successful inclusion of C.

 

 

Handling procedure:

To compensate the link loss, amplifier will be changed at transmitting and receiving direction at both existing node. Presently the link loss from “A” to “B” is 37.1 dB and from "B" to "A" is 33.5dB.

Optical Layer preparation:

The existing optical layer at both sides is OAU105 in thr Tx direction and OBU104 and OAU101 in the receiving direction.

For the inclusion of new node, link loss is give below

Link Name	Distance(KM)	Fiber Loss(dB)
C-A	73	24
C-B	44	16

For A-C link in Node "A" the directional subrack to "C" the optical layer will be OAU106 in Tx direction and OAU101 in the receiving direction.

For B-C link in Node "B" the directional subrack to "C" the optical layer will be OAU106 in both Tx and Rx direction.

Before migration new Node C will be commissioned and included successfully between A and B.

Optical layer change procedure

After including new node C in A-B link we require to change optical layer at A and B link. The processes are described in the following:

 

Step 1: Delete optical Cross connection

To modify the optical layer we have to delete the optical cross connection between TM20 to SFIU and SFIU to TD20 for 04 lambdas such as 28,32,56,66 at A and C site. Before deleting optical x-connection, we need to keep records for amplifier gain, input and output power as well as VOA for all WSS boards.

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Step 2: Delete Internal Fiber connection

As the transmission direction amplifier for both sides will only be replace with OAU106 board. So we don’t require deleting internal fiber for transmission direction amplifier. We will delete internal fiber for both amplifiers in receiving direction.

Step 3: Delete OBU104 board in receiving direction

After deleting internal fiber we will delete OBU104 board in both Band A site.  

Step 4: Replace Boards

For A node, we don’t require to install new board in the receiving direction as the existing board type OAU101 which is matched with our plan. But B site we require to replace OAU101 board with OAU106 board. The steps will be plug-out existing board and install new board in the same slot with same fiber connection.

In transmission direction of both sides we will replace OAU105 with OAU106. The steps will be same like before_ plug-out existing board and install new board in the same slot with same fiber connection.

 

 

 

Step 5: Create Internal Fiber on the EMS

After finish replacement of boards we will create internal fiber between SFIU-OAU1 and OAU1-WSMD4 board in EMS for both sides.

Step 6: Create Optical Cross connection

After finish internal fiber, we will create the optical cross connection   betweenTM20 to SFIU and SFIU to TD20 for 04 lambdas such as 28,32,56,66 at A and B site.

Thus finish existing node preparation mainly amplifier change in optical direction.

These steps will be done during migration night activity and just after the successful implementation of node inclusion.

     Thus finish our migration work for A-Blink.

     

       Suggestion and summary:

Before optical layer change, new node commissioning has to be done precisely. To be noted that record of VOA, gain, optical cross-connection should be kept for accurate optical layer grooming. During new node inclusion, line fiber should be removed carefully and connected to the desired ODF port.

 

 

 

 

Its a short description , but still informative

Posted by gigi at 2016-08-16 12:23 Its a short description , but still informative

Thanks for your feedback.

did you use Raman amplifier prior adding Node C in the link, as previous cumulative loss is approx 40db?

Nice one!

Posted by faheem180 at 2016-08-26 16:32 did you use Raman amplifier prior adding Node C in the link, as previous cumulative loss is approx 4 ...

No we didn't use RAMAN amplifier. We used EDFA amplifier in this case.

Posted by sazzad at 2016-08-26 20:27 Nice one!

Thanks!!!

Posted by faheem180 at 2016-08-26 16:32 did you use Raman amplifier prior adding Node C in the link, as previous cumulative loss is approx 4 ...

we use two amplifier in series like received signal will be boosted first through booster amplifier and then amplified through gain adjustable amplifier.

have you experienced any BERs prior adding node C with that big span loss.

and what were the services 10G or 100G?