Cable Management and Slack Storage

The successful slack storage system provides flexible storage capacities, permanent bend radius protection, and easy access to individual fibers.. Although many may be less inclined to r

Cable Management and

Slack Storage

Taking Up the Slack in Cable Management

Over the years, more and more people have become experienced in working with optical fiber, particularly in the central office (CO) environment One bit of knowledge obtained quickly through experience is the importance of fiber cable management and how it can dramatically affect the operational costs of a network ADC has a wealth of experience

in the areas of cable management and slack storage systems that are time-tested and continually improved – but it all begins with pure awareness

Storing excess fiber cable is an often overlooked area within the fiber-to-the-premise (FTTP) network’s outside plant (OSP) architecture, yet it is critical when it comes to preventing cable management problems For example, excess patch cord fiber is usually necessary for reconfiguring a fiber circuit, but the slack must be managed to prevent damage At the same time, all fibers should remain as accessible as possible during day-to-day operations of the network

Accessibility and the amount of time required to reconfigure a network will be optimized

in a system that maintains a continuous non-coiled or twisted routing of the fibers The successful slack storage system provides flexible storage capacities, permanent bend radius protection, and easy access to individual fibers It will also mitigate many potential problems that non-managed systems could face over time

Keys to Unlocking Fiber Management

Good fiber cable management can be broken down into a few key principles The first principle is to develop clear routing paths that are obvious to any technician at a glance In other words, routing the fiber correctly should be intuitive and easily accomplished Next, fiber cable should be physically protected to prevent damage as a result of technicians working on other parts of the cabinet or cable management device Measures should be taken to avoid damaging, pulling, stretching, crushing or pinching existing fibers in the vicinity of the work area

Another key to cable management is bend radius protection As fiber is bent, the radius can become too small and allow light to escape the core and enter the cladding The result is insertion loss in the fiber or a macrobend that decreases the signal or, in extreme cases, causes complete signal loss and data transfer failures Finally, an integrated slack storage strategy or system is necessary Each fiber, due to the high tolerance needed, is normally terminated in the factory to eliminate the high costs involved with field terminations This typically results in fixed cable lengths and patch cords Once the technician arrives at the job site to make a connection, the fiber cable or patch cord may be longer than what is actually required Therefore, a system must allow the proper storage of the slack – the difference in length between what is actually needed to physically make the connection, and what the technician actually has to work with

Cable Management and Slack Storage

These storage management principles have evolved

within the CO environment for making a network both

reliable and operationally efficient Now that fiber is

being pushed deeper into the access network,

particularly as fiber-to-the-premise (FTTP) architectures

begin to deploy, these same principles will apply to

ensure the operational efficiency of the access portion

as well

Although many may be less inclined to realize the

importance of cable management in the access

network due to less data traveling across a single fiber,

it’s critical to realize that far more fibers are being

deployed in comparison to the core network

Therefore, individual management of fiber becomes

even more important since each fiber’s reliability is

directly tied to customer satisfaction

CO Techniques Outside the CO

Since the fiber distribution hub in the access network’s

outside plant is very similar to a CO’s fiber frame device,

it makes sense that the same cable management

techniques should be put into practice But since the

fiber distribution panel is located in the middle of a

neighborhood, environmental issues must also be

considered Additionally, a single technician is likely to

have many different responsibilities while not specializing

in how a particular piece of equipment operates This

scenario generates an even greater need for effectively

dealing with fiber cable management issues

For example, when the technician arrives at the

distribution cabinet, he may not be familiar with exactly

how previous fiber cables and connections have been

made In fact, it could be the first time he’s opened this

particular cabinet With that in mind, it’s easy to see the

importance of a system that not only achieves routing

paths that are intuitive, easy to find, and clear, there

should also be documentation right at the point of use

that enables the technician to remember and implement

standard cable management techniques

Outside temperature variations also can cause fiber cable

management issues Although the fiber isn’t affected by

fluctuating temperatures, the jacketing materials can

shrink and expand, causing bend radius problems

Technicians must ensure all fiber cables are constrained

around the bend radius while permitting shrinkage in

cold temperatures

Other less common scenarios, yet still worthy of

consideration, might include the possibility of having to

completely restore a fiber distribution cabinet that was

struck by a vehicle Is there a plan in place for quickly

restoring or replacing the cabinet? Typically, this involves

having some coils of slack storage below the ground or

up on a pole that allows replacement of the entire cabinet or modular items within the cabinet

In a typical FTTP architecture, it is often common to place only half the terminations within the distribution cabinet and allow for future expansion The cable management system should be adaptable to routing any splitter port

to any connector port, making it easy to add more connections without affecting the cable management that exists for the original fibers

In fact, the ability to route from any splitter port to any distribution port is a key issue within the cabinet Making sure the cable management is in place to support the clear routing paths, store slack cable, provide physical protection, and achieve proper bend radius protection from day one to several years after deployment will provide operational cost savings for the service provider

Getting to Every Connector

Finally, easy connector access is a vital part of any cable management system Technicians should be able to access any individual connector for cleaning, maintenance, and troubleshooting Cleaning connector endfaces is no less important in the access network than

in the CO environment A small speck of dust on an endface can jeopardize a successful optical connection Since many of the access network connections are made

in the outside plant portion of the network, there is wind and contaminants to raise the probability of an exposed endface attracting debris Therefore, cleaning both the front and rear connections in the panel is necessary and requires adequate access Dust covers on the connectors and adaptors are designed for keeping debris off the endface, but they are always dependent on how technicians use them Dust covers never negate the need for cleaning each time a connection is made

Typically, some slack fiber is left on the backside of a patch panel in the event of a failed or broken connector

or fiber This enables the opportunity to restore service to the cabinet by having extra fiber to use There should be

a place for storing a number of splices and a way to access that area – along with extra slack cable that enables quick restoration when necessary

Fiber cable management techniques play as important a role in the access network as they have traditionally played in the CO The fiber distribution hub is a particularly crucial area due to the large number of connections and fibers present

However, other areas that deserve consideration for cable management include the fiber access terminals farther up the access network Here again, the same key techniques apply for cable routing, slack storage, physical protection,

and bend radius considerations Additionally, the

optical network terminal (ONT) at the extreme end

of the network, although only dealing with one or

two fibers, is also a candidate for bend radius and

physical protection issues

ADC believes that proper cable management

techniques will optimize access networks in terms

of accessibility and the amount of time required to

reconfigure a network Successful cable

management is key to eliminating many potential

problems that non-managed systems will likely

face in their future

ADC Telecommunications, Inc., P.O Box 1101, Minneapolis, Minnesota USA 55440-1101 Specifications published here are current as of the date of publication of this document Because we are continuously improving our products, ADC reserves the right to change specifications without prior notice At any time, you may verify product specifications by contacting our headquarters office in Minneapolis ADC Telecommunications, Inc views its patent portfolio as an important corporate asset and vigorously enforces its patents Products or features contained herein may be covered by one or more U.S or foreign patents An Equal Opportunity Employer

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