OSP Design Process of Fiber Optic Network

OSP Design Process: Today I will explain about the OSP design process including FIBER OPTIC CABLES (FOC) like "use of existing Fiber Optic Cables (FOC),selection of Fiber Optic Cable (FOC)" etc. First I will explain the general consideration in OSP design process like "use of existing Civil Infrastructure (C-OSP), Design of new Civil Infrastructure (C-OSP),Conduit reserve" etc.

As you know OSP design play a very important role in the optical fiber network. Fiber optic network fully depend upon the fiber planning and OSP design.How to connect,where to connect a customer its all depend upon the planning and design. overall today we will discuss about the OSP design process.It is also a important part of Fiber Optic Network.

OSP Design for Fiber Optic Network

OSP Design Process of Fiber Optic Network

CIVIL INFRASTRUCTURE IN OSP DESIGN PROCESS

Use of existing Civil Infrastructure (C-OSP)

To prevent unnecessary expenses in civil works, the OSP-Designer will use existing civil infrastructure as far as possible in any design, unless otherwise indicated by NP through a mandatory Physical Path (PP). Prior, the OSP-Designer will check whether those existing civils are in proper condition, not congested and fit for purpose The network survey activity is a key activity that will confirm the PP and should be performed.

Design of new Civil Infrastructure (C-OSP)

When existing infrastructure is not available or not suitable and the construction (check the company rule & process for new civil work) of new civil infrastructure is required, the design must always be ruled by the guidelines contained in telecom companies civil design guidelines. Practices on civil infrastructure imposed by government authorities must also be respected.

Conduit reserve

Whether new or existing civil infrastructure, the OSP-Designer will enforce in his design that all the Physical Path Sections (PPS) remain with at least 1 empty and available microduct/subduct/duct after all the planned FOCs are being installed. Be aware that not all empty ducts could be fully accessible in a PPS. For example, ducts at the bottom of a manhole could be obscured by cables above, or across them, preventing FOCs from being inserted.

Facing a conduit scarcity issue, the OSP-Designer will check if sub-ducting could be a viable way to gain conduit capacity or study and validate alternative and less congested physical routes.In the event that the OSP-Designer will not find any suitable alternative to keep 1 available conduit in any PPS, he will return to Network Planning to notice the circumstance and validate a solution.

Maximum Physical Path Section (PPS) length

The OSP-Designer will check if the lengths of all the Physical Path Sections (PPS) are into accepted margins,according to the below table. Should that not be the case in any particular location, the OSP-Designer should study and validate alternative PP routes.

Maximum Physical Path Section (PPS) length

PPS Length accepted margins

In the event that the OSP-Designer will not find any suitable alternative to accomplish the PPS maximum length, he will return to NP to communicate the circumstances whilst proposing an alternative solution.

Physical Path Enclosure (PPE) suitable to allocate FOSC and CSL

Where required, the OSP-Designer will check if the appointed Physical Path Enclosures (PPE) have the right size, that they are not congested and in a proper condition to house either a Fiber Optic Splice Closures (FOSC) or a FAT, with the needed Cable Slack Loops (CSL).

In the event that an appointed PPE is not suitable, the OSP-Designer will select and validate an alternative PPE nearby.In the event that the OSP-Designer cannot find any suitable alternative for a mandatory PPE, he will return to Network Planning to communicate the circumstances whilst proposing a solution.

Construction/Repair of Civil Infrastructure (C-OSP)

It is very likely that the design would require the construction or repair of PPS or PPE along the designed routes. This could be due, but not limited to, inexistent infrastructure, lack of existing duct space, blocked ducts, collapsed ducts, or lack of access to existing duct space.

Sometimes, the construction of new civil infrastructure is driven by the goal to improve the network or get a more valuable scope.

In either case, the OSP-Designer will check if the construction or repair is included in the scope of work of the design assignment. Whether the construction/repair is not included and/or the cost exceeds the PD budget, the OSP-Designer will return to Network Planning to communicate the circumstances and wait for further instructions before resuming design.

FIBER OPTIC CABLES (FOC)

Use of existing Fiber Optic Cables (FOC)

The use of existing Fiber Optic Cables in any design, if different than what is proposed in the PD, should always be approved by company Senior Designer/Design Manager.The OSP-Designer can’t use any existing and installed Fiber Optic Cable (FOC) in his design unless expressly validated by the company Senior Designer/design manager.

Single Fiber Optic Cable (FOC) per conduit

The preferred installation layout is a single FOC per conduit. All the FOCs to be designed have to be installed in an individual conduit in each Physical Path Section (PPS) along their path.

The OSP-Designer will check if sub-ducting could be a viable way to provide an individual conduit per FOC or study and validate alternative physical routes on new or existing civil infrastructure.

In the event that the OSP-Designer cannot find any suitable alternative to assign a conduit to a FOC in any PPS, he will return to NP to communicate the circumstances whilst proposing a solution.

Select Fiber Optic Cable (FOC) for the appropriate placement method

The OSP-Designer will select in his design the FOC reference that fits with the placement method in the route, whether traditional pulling or blowing. As a general rule, a FOC for blowing cannot be pulled, and a FOC for pulling is not optimized to be blown.

Duct Fill Ratio (DFR) for Fiber Optic Cables (FOC)

The OSP-Designer will enforce the DFR into accepted margins in all the Physical Path Section (PPS) of the path, for details following the below table. Should that not be the case in any particular portion, the OSP-Designer should study and validate an alternative PP routes on new or existing civil infrastructure.

FOC placement method

FOC Fiber-Count and placement method

In the event that the OSP-Designer will not find any suitable alternative to accomplish the DFR, he will return to NP to communicate the circumstances.

Sub-ducting Physical Path Sections (PPS)

The OSP-Designer should consider sub-ducting one large-size duct as a viable way to gain conduit capacity in congested PPS. Be aware that not all empty ducts would be accessible in a PPS to allow the maximum number of sub-ducts to be inserted. For example, ducts at the bottom of a manhole could be obscured by cables above, preventing sub-ducts from being inserted.

The number of subducts or microducts to install in a large-size duct depends on its size and whether this duct is already occupied by another cable or subduct.

The OSP-Designer will subduct with 32/26 subducts whether the designed FOCs will be placed by pulling, and 20/16 microducts in case of placement by blowing.

FOC ROUTES

Hazardous and Mandatory Physical Sections

Occasionally, the PD document can detail Hazardous Physical Sections for a particular FOC route. Those sections are prohibited in the route of that FOC. In turn, the PD document can also occasionally detail Mandatory Physical Sections for a particular FOC. Those sections are mandatory in the route of that FOC.

The OSP-Designer will always select routes that accomplish the mandatory and hazardous sections requirements stated in the PD. Should that not be possible to accomplish, the OSP-Designer will return to Network Planning by providing details and await further instructions.

Flat Architectures

Physical Path Sections (PPS) can provide support to multiple Fiber Optic Cables (FOC) at the same time. Therefore, they can be considered as shareable network infrastructure. That “multiplexing” feature is relevant while designing protected topologies. Considering whether both routes (main and diversity) are permitted to do/don’t share a portion of their physical paths,

The OSP-Designer will always select physical routes that accomplish the Flat Architectures requirements. Should that not be possible to accomplish, the OSP-Designer should study and validate alternative PP routes on new or existing civil infrastructure.

Route amendments that require Network Planning approval

The OSP-Designer can make some amendments onto the provisional physical routes provided by Network Planning. The amendments suggested/introduced by the OSP-Designers will not require Network Planning validation if all the conditions listed below happens. Should that not be the case, the OSP-Designer will return to Network Planning for validation.

➥Changes don't represent a length variation of more than 10% of the original route.

➥In case that installation has to be done in a specific timeframe, changes don’t introduce a severe delay in the planned installation timeframe, extending the schedule in more than 20% of its former time duration.

➥Changes don’t increase the project budget in more than 10%.

➥Hazardous Sections and Mandatory Sections are still respected.

➥Flat Architectures are still respected.