U.S. patent application number 11/699716 was filed with the patent office on 2009-12-24 for fiber distribution hub with half-loop pigtail storage.
This patent application is currently assigned to Fiber Optic Network Solutions Corporation. Invention is credited to Jeff Gniadek, Michael Noonan, Tom Parsons, Randy Reagan.
Application Number | 20090317045 11/699716 |
Document ID | / |
Family ID | 34574065 |
Filed Date | 2009-12-24 |
United States Patent
Application |
20090317045 |
Kind Code |
A1 |
Reagan; Randy ; et
al. |
December 24, 2009 |
FIBER DISTRIBUTION HUB WITH HALF-LOOP PIGTAIL STORAGE
Abstract
A method for configuring an enclosure used in a communications
network is described. The method may include providing a group of
pigtails. The method may further include routing the group of
pigtails circumferentially around a subscriber termination field,
where the group of pigtails is associated with an optical splitter
module used to convey optical signals to a destination, and where
the routing is performed in a manner that does not substantially
obstruct access to at least one of a group of subscriber
terminations that are associated with the subscriber termination
field.
Inventors: |
Reagan; Randy; (Clinton,
MA) ; Gniadek; Jeff; (Northbridge, MA) ;
Parsons; Tom; (Leominster, MA) ; Noonan; Michael;
(Shrewsbury, MA) |
Correspondence
Address: |
MERCHANT & GOULD PC
P.O. BOX 2903
MINNEAPOLIS
MN
55402-0903
US
|
Assignee: |
Fiber Optic Network Solutions
Corporation
Northborough
MA
|
Family ID: |
34574065 |
Appl. No.: |
11/699716 |
Filed: |
January 29, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11225099 |
Sep 14, 2005 |
7171102 |
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11699716 |
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11155818 |
Jun 20, 2005 |
7088899 |
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11225099 |
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10714814 |
Nov 17, 2003 |
6983095 |
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11155818 |
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Current U.S.
Class: |
385/135 |
Current CPC
Class: |
G02B 6/4452 20130101;
H04Q 1/14 20130101; H04Q 1/021 20130101; H04Q 2201/804 20130101;
H04Q 2201/10 20130101 |
Class at
Publication: |
385/135 |
International
Class: |
G02B 6/00 20060101
G02B006/00 |
Claims
1-9. (canceled)
10. A fiber distribution hub comprising: an enclosure; a subscriber
termination field mounted within the enclosure, the subscriber
termination field having a first end and a second end vertically
spaced from the first end, the subscriber termination field also
having a side extending between the first and second ends, the
subscriber termination field including a plurality of subscriber
terminations, each of the subscriber terminations being associated
with a subscriber; an optical splitter module mounted within the
enclosure; and a plurality of pigtails having connectorized ends,
the pigtails being optically coupled to the optical splitter module
and being routed laterally along at least part of the first end of
the subscriber termination field and along the side of the
subscriber termination field from the first end of the subscriber
termination field past the second end of the subscriber termination
field, and being looped back around past the second end to couple
the connectorized ends to the subscriber terminations of the
subscriber termination field.
11. The fiber distribution hub of claim 10, further comprising: a
transition member arranged within the enclosure adjacent the first
end of the subscriber termination field, the transition member
configured to receive a ribbon cable and to output the
pigtails.
12. The fiber distribution hub of claim 11, wherein the optical
splitter module is configured to output the ribbon cable, wherein
signals received at the optical splitter module are transmitted to
the ribbon cable.
13. The fiber distribution hub of claim 12, wherein the optical
splitter module is mounted adjacent the second end of the
subscriber termination field.
14. The fiber distribution hub of claim 10, wherein the enclosure
defines a vertical channel, and wherein the pigtails are routed
from the first end of the subscriber termination field, through the
vertical channel, and past the second end of the subscriber
termination field.
15. The fiber distribution hub of claim 10, wherein the pigtails
are looped back around in a half-loop configuration.
16. The fiber distribution hub of claim 10, wherein each pigtail
has a length, and the length of each pigtail is equal to the length
of each other pigtail.
17. The fiber distribution hub of claim 11, wherein each pigtail
has a length sufficient to extend from the transition member to any
of the subscriber terminations in the subscriber termination
field.
18. The fiber distribution hub of claim 11, further comprising: a
splice tray arranged within the enclosure, the splice tray arranged
on an opposite end of the subscriber termination field from the
transition member.
19. A fiber distribution hub comprising: an enclosure; an optical
splitter mounted within the enclosure; a subscriber termination
field mounted within the enclosure, the subscriber termination
field having a top end, a bottom end and two sides, the subscriber
termination field including a plurality of subscriber terminations;
and a plurality of pigtails having connectorized ends, the pigtails
being routed laterally above at least a portion of the top end of
the subscriber termination field, downwardly along at least a
portion of one of the sides of the subscriber termination field,
and looped upwardly to couple the connectorized ends to the
subscriber terminations of the subscriber termination field.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 11/225,099, filed on Sep. 14, 2005, which is a
divisional of U.S. patent application Ser. No. 11/155,818, filed on
Jun. 20, 2005, now U.S. Pat. No. 7,088,899, which is a continuation
of U.S. patent application Ser. No. 10/714,814, filed on Nov. 17,
2003, now U.S. Pat. No. 6,983,095, which applications are hereby
incorporated by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] In Fiber-to-the Premises broadband network applications
optical splitters are used to split the optical signals at various
points in the network. Recent network specifications call for
optical splitters to be incorporated in Fiber Distribution Hubs
which are re-enterable outdoor enclosures. These enclosures allow
easy re-entry for access to optical splitters allowing splitter
ports to be utilized effectively and for additional splitter ports
to be added on an incremental basis.
[0003] In typical applications to date, optical splitters are
provided prepackaged in optical splitter module housings and are
provided with splitter outputs in pigtails that extend from the
module. The splitter output pigtails are typically connectorized
with high performance low loss SC or LC connectors. This optical
splitter cassette provides protective packaging for the optical
splitter components in the housing and thus provides for easy
handling for otherwise fragile splitter components. This approach
allows the optical splitter modules to be added incrementally to
the Fiber Distribution Hub, for example, as required.
[0004] A problem arises due to the lack of protection and
organization of the connectorized ends of the splitter output
pigtails. These pigtails can sometimes be left dangling in a cable
trough or raceway within the enclosure. This method of leaving an
exposed optical component such as a high performance connector
exposed in an open area leaves it susceptible to damage. The high
performance connectors, if damaged, can cause delays in service
connection while connectors are repaired. Leaving connectorized
splitter output pigtails dangling in a cabling trough also exposes
them to dirt and debris in the cabling trough. In current network
deployments, it is desirable to maintain clean optical connectors
to maximize the performance of the network.
[0005] In addition, the fiber pigtails in the current art are not
organized in a manner conducive to rapid service delivery. In many
cases, the splitters may have sixteen or thirty-two output pigtails
bundled together making it difficult to find a particular pigtail.
Also the bundle of loose hanging pigtails can easily become
entangled causing further delays in service delivery. The tangles
can actually cause congestion and in some cases result in bend
induced loss on the pigtails resulting in overall lower system
performance.
[0006] To solve some of these issues, a separate storage tray or
enclosure has been utilized to take up slack and/or store and
protect splitter output pigtail connectorized ends. However, these
auxiliary devices tend to take up additional space and often hide
the pigtail in an enclosure that can cause further delays in
deployment depending on how much time is required to access on the
tray or enclosure. Thus, there still remains a need for a solution
that does not take up additional space and that provides direct
access and identification to splitter output pigtail ends.
[0007] In addition, some network applications may require equipping
splitter outputs with fiber optic terminators in order to eliminate
reflections caused by unterminated splitter outputs. Other methods
of storing connectorized pigtails in cable troughs or auxiliary
trays may make it difficult to equip splitter output ports with
fiber optic terminators.
[0008] Finally, current methods tend to result in a disassociation
of the splitter module from the splitter output pigtail end. This
usually results because the pigtail, once deployed, gets lost in
the midst of other pigtails in the fiber jumper trough. When
subscribers are taken out of service, it is desirable to disconnect
the splitter output and redeploy or store it for ready
redeployment. It is further desirable for administrative purposes
to maintain association of splitter module to splitter output
pigtails so that resources are used effectively over time.
SUMMARY OF THE INVENTION
[0009] In accordance with an implementation, a method for
configuring an enclosure used in a communications network is
provided. The method may include providing a group of pigtails. The
method may include routing the group of pigtails circumferentially
around a subscriber termination field, where the group of pigtails
is associated with an optical splitter module used to convey
optical signals to a destination, and where the routing is
performed in a manner that does not substantially obstruct access
to at least one of a group of subscriber terminations that are
associated with the subscriber termination field.
[0010] In accordance with another implementation, an optical
splitter module for use in an optical communications network is
provided. The optical splitter module may include an optical
splitter configured to split an incoming optical signal into a
group of outgoing optical signals. The splitter module may include
a faceplate configured to make the group of outgoing optical
signals available to a group of pigtails, where each of the group
of pigtails is configured to couple a respective one of the group
of optical signals to one of a group of subscriber terminations
associated with a subscriber termination field. The faceplate may
be configured to facilitate incremental deployment of the optical
splitter module on a shelf in a manner that facilitates making
optical signals from the group of optical splitter modules
available to the subscriber termination field.
[0011] In accordance with yet another implementation, an enclosure
for distributing optical communication signals is provided. The
enclosure may include a subscriber termination field mounting area
configured to support a subscriber termination field including a
group of subscriber terminations, where each of the group of
subscriber terminations is associated with a subscriber. The
enclosure may include an optical splitter shelf configured to
support a group of optical splitter modules, where each of the
group of optical splitter modules has a group of pigtails that
includes a transition member, and where the group of pigtails is
adapted to convey optical communication signals to at least some of
the group of subscriber terminations. The enclosure may include a
transition member mounting area configured to support a group of
transition members to facilitate circumferential routing of the
group of pigtails around the subscriber termination field.
[0012] In accordance yet another implementation, a method for
connecting a subscriber to an optical communications network is
provided. The method may include removing a pigtail connector from
a parked location associated with a receptacle. The method may
include coupling the pigtail connector to a subscriber termination
associated with a subscriber, where the subscriber termination is
one of a group of subscriber terminations associated with a
subscriber termination field. The method may include storing slack
associated with the pigtail in a vertical channel within an
enclosure to facilitate routing the pigtail in a manner that does
not substantially interfere with others of the group of subscriber
terminations.
[0013] The foregoing and other features and advantages of the
systems and methods for fiber distribution and management will be
apparent from the following more particular description of
preferred embodiments of the system and method as illustrated in
the accompanying drawings in which like reference characters refer
to the same parts throughout the different views. The drawings are
not necessarily to scale, emphasis instead being placed upon
illustrating the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 illustrates schematically a broadband access network,
for example, a fiber-to-the-premises (FTTP) network using passive
optical network (PON) components in accordance with a preferred
embodiment of the present invention.
[0015] FIG. 2 illustrates schematically further details of an FTTP
network in accordance with a preferred embodiment of the present
invention.
[0016] FIG. 3 illustrates an optical splitter module in a fiber
distribution network having connectorized pigtails in accordance
with a preferred embodiment of the present invention.
[0017] FIG. 4A schematically illustrates the installation of the
optical splitter module pigtails in accordance with a preferred
embodiment of the present invention.
[0018] FIG. 4B schematically illustrates the service connection
configuration of the optical splitter module in accordance with a
preferred embodiment of the present invention.
[0019] FIGS. 5A and 5B schematically illustrate the installation of
the optical splitter module pigtails and the service connection
configuration of the optical splitter module, respectively, in a
network having modules adjacent to each other in accordance with a
preferred embodiment of the present invention.
[0020] FIGS. 5C and 5D schematically illustrate the service
connection configurations between adjacent fiber distribution hubs
in accordance with alternate preferred embodiments of the present
invention.
[0021] FIG. 6 is a flow chart illustrating a method for installing
and connecting optical splitter module pigtails in accordance with
a preferred embodiment of the present invention.
[0022] FIGS. 7A-7E illustrate views of the fiber distribution hub
in accordance with preferred embodiments of the present
invention.
[0023] FIG. 8 illustrates a view of the internal components of a
fiber distribution hub enclosure in accordance with a preferred
embodiment of the present invention.
[0024] FIG. 9 illustrates a schematic view of a fiber distribution
hub enclosure having a side-by-side equipment configuration in
accordance with a preferred embodiment of the present
invention.
[0025] FIG. 10 illustrates a view of the optical component modules
used in a fiber distribution hub enclosure in accordance with a
preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The preferred embodiments of the present invention are
directed to an optical splitter module that is equipped with
adapters for storing connectorized optical splitter pigtail ends.
Adapters are administratively located on the optical splitter
module bulkhead, for example, but not limited to, in octal count
arrangements ideally suited to identify splitter ports having
sixteen or thirty-two output ports. The adapters in accordance with
preferred embodiments are used to store or stage the connectorized
ends of the optical splitter for rapid location, identification,
easy access and removal of pigtail output ends. In accordance with
preferred embodiments, the optical splitter outputs extending from
the bulkhead on the module are wrapped back and secured to adapters
on the splitter bulkhead. The preferred embodiments also include
methods for installing optical splitter modules and associated
fixed length output pigtails, storing the connectorized ends of the
pigtails in a position ready for deployment and then individually
connecting the splitter outputs as required to connect service to
subscriber terminations.
[0027] FIG. 1 illustrates schematically a broadband access network
10, for example, a Fiber-to-the-Premises (FTTP) network using
passive optical network (PON) components in accordance with a
preferred embodiment of the present invention. The architecture can
be a point to multi-point PON construction, which utilizes 1:32
splitters at a fiber hub enclosure within the distribution area.
The architecture can be fiber rich 1:1 distribution between the
fiber hub and a customer's premise. The broadband services
capability of the network to distribute source information include,
for example, data signals (622 Mbps.times.155 Mbps (shared)), and
video signals (860 MHz, .about.600 analog and digital channels,
high definition television (HDTV), and video on demand (VOD)).
Signaling is accomplished using wavelength division multiplexing
(WDM) and fiber sharing. The network includes the optical network
terminals 26 that are scalable, provide high bandwidth,
multi-service applications that serve residences and small/medium
businesses. The network 10 includes passive components that are
located outside the plant and require minimal maintenance.
[0028] The broadband access network 10 includes digital subscriber
plug-in line cards that have a broadband terminal adapter
configured for receiving a digitally multiplexed broadband data
stream and outputting a group of demultiplexed broadband data
streams for the respective subscriber loops.
[0029] FIG. 2 illustrates schematically further details of an FTTP
network 50 in accordance with a preferred embodiment of the present
invention. In Fiber-to-the-Premises broadband network applications
optical splitters 64 are used to split the optical signals at
various points in the network. In FTTP networks optical splitters
are typically located in both indoor and outdoor environments
including a Central Office/Head End, environmentally secure
cabinets, enclosures or drop terminals. In some outdoor
applications, optical splitters have been deployed in tightly
sealed environmental closures that are not easily re-enterable.
Preferred embodiments of the present invention provide optical
splitter enclosures to effectively utilize splitter ports or to
incrementally deploy additional splitters as the need arises.
Preferred embodiments include optical splitters incorporated in
Fiber Distribution Hubs 54 which are re-enterable outdoor
enclosures. These enclosures allow easy re-entry for access to
optical splitters allowing splitter ports to be utilized
effectively and for additional splitter ports to be added on an
incremental basis.
[0030] Preferred embodiments of the present invention include
optical splitters that are provided prepackaged in optical splitter
module housings that are mounted in a fiber patch panels to
facilitate routing of jumpers interconnected from fibers in
adjacent subscriber ports to the splitter outputs. This optical
splitter cassette provides protective packaging and thus easy
handling for otherwise fragile splitter components. The optical
splitter modules can be added incrementally to the patch panel.
[0031] FTTP broadband networks are designed to achieve low optical
insertion loss in order to achieve maximum network reach from
electronics having fixed power output. Each optical component and
subsystem utilized in the network is optimized to provide minimum
insertion loss. The optical loss budget in a preferred embodiment
is approximately 23 to 25 dB with 1:32 passive splitting. The
components and factors contributing to the optical loss include
splitters (1:32, single or cascaded), WDMs, connectors (optical
line terminal (OLT), FDF, splitters, drop, ONT), fiber attenuation
(at least three wavelengths: 1310 nm, 1490 nm, 1550 nm), and
splicing.
[0032] The splitter hub 54 serves at least 128 splitter
ports/premises. It includes multiple distribution cables,
connectorized or fused between splitter and distribution. The
preferred embodiments of the present invention provide efficient
fiber connection and management with easy access, and low
maintenance requirements. The splitter hubs of the preferred
embodiments are pole or ground mountable. The drop terminals can be
with or without splitters and include various number of drops, both
aerial and buried.
[0033] In preferred embodiments, optical connectors are used in the
network to provide the desired flexibility however they are
restricted to those points in the network where flexibility is
absolutely required. Optical connectors are required to provide
flexible access to optical splitter outputs. The preferred
embodiments of the present invention provide connector flexibility
and yet minimize optical loss using the optical splitter module
with connectorized pigtails. The pigtails have standard SC or LC
type connectors on the ends.
[0034] FIG. 3 illustrates an optical splitter module 100 in a fiber
distribution network having connectorized pigtails in accordance
with a preferred embodiment of the present invention. The module
100 includes a bulkhead faceplate 102 having storage receptacles
112. In a preferred embodiment, the optical splitter module 100
provides for a high density ribbon cabling harness 106 to protect
the splitter outputs extending from the splitter module 100. The
optical splitter module ribbon harness 106 is secured to the module
100 with a strain relief mechanism 104 to provide high pull
strength and bend radius control. The compact nature of the ribbon
harness 106 allows for higher packing density and better space
utilization in the cabling trough. The module ribbon harness
cabling 106 is converted to individual pigtails with connectors to
allow splitter outputs to be administered and rearranged
individually.
[0035] The module 100 may be equipped with either half
non-functional adapters or full functioning adapters as a means for
storing pigtail ends. In a preferred embodiment, the half
non-functional adapters are used in applications not requiring
fiber optic terminators but for storage functionality. The full
functional adapters are used in applications requiring connection
of fiber optic terminators to the optical splitter output port.
Access to the pigtail ferrule tip may be required for attaching
fiber optic terminators to eliminate undesirable reflections caused
by unterminated connectors. The module 100 provides a home position
from which optical splitter output pigtails can be deployed and
where they can be returned to once taken out of service. This
administrative use of adapters provides protection for the
connectorized pigtails ends 110, maintains cleanliness of the
connector ends, and enables rapid service connection and
deployment.
[0036] The preferred embodiments of the present invention address
configuring a fiber distribution hub with optical splitter modules
having fixed length connectorized pigtails. One aspect of the
preferred embodiment determines where to position the optical
splitter modules relative to other fiber terminations needing
access to the optical splitter ports. The preferred embodiments
also addresses installing the pigtails in a configuration that
requires minimal pigtail rearrangement and slack yet allowing for
enough slack to reach any of the fiber terminations requiring
access to splitter ports. The methods of installing optical
splitter module pigtails include determining how to route the
pigtails in order to provide an optimal routing scheme that does
not get congested and wherein slack can be controlled within set
limits of the enclosure. The methods in accordance with a preferred
embodiment of the present invention include making all pigtails the
same length for ease of manufacturing and ordering by the customer.
Splitter modules all having the same pigtail length also allow ease
of flexibility for allowing a splitter module to be installed in
any available slot within the patch panel without regard to
sequential order.
[0037] A preferred embodiment of the method for installing the
splitter module pigtails also provides for fiber management in the
enclosure so that rearrangement and churn does not congest this
management. To accomplish this, the slack and any chance of
blocking access because of fiber entanglement is minimized. The
preferred embodiments allow for churn over time including initial
pigtail storage, service connection, service disconnection and
repeat storage to provide ready access to pigtails for future use.
The methods of the present invention are non-blocking and
non-congesting for jumpers routed into cable pathways and fiber
patch panels. The method of a preferred embodiment is fully
contained within the confines of the enclosure.
[0038] FIG. 4A schematically illustrates the installation of the
optical splitter module pigtails in accordance with a preferred
embodiment of the present invention. A preferred embodiment of the
present invention includes a cabling installation method 125
including splitter modules incrementally installed on a shelf
adjacent to a subscriber termination field 128. The connectorized
pigtails 138 from the splitter modules 132 having fixed identical
length are routed in a circumferential path 130 surrounding the
subscriber termination field 128. The connectorized ends of the
pigtails are stored at a position on the front of the splitter
module 132 via storage receptacle 134. The method in accordance
with a preferred embodiment employs a fan through placement so that
the splitter module pigtails can be installed without disturbing
installation of pigtails already connected to subscriber
terminations. This installation method in accordance with a
preferred method of the present invention also ensures that the
splitter module 132 can be preconfigured with the pigtail
connectors in the storage position and left in the storage position
throughout the pigtail installation process.
[0039] FIG. 4B schematically illustrates a service connection
configuration 150 of the optical splitter module in accordance with
the preferred embodiment of the present invention shown in FIG. 4A.
The preferred embodiments of the present invention, include a
service connection method to connect a subscriber into service by
first disconnecting an individual splitter output pigtail from the
storage position and then routing the pigtail to the desired
subscriber port 152. Since the pigtail harness has been
preconfigured and routed circumferentially around the subscriber
termination the pigtail inherently reaches any of the desired
subscriber ports within the target population by simply reducing
the circumferential path distance. By reducing the circumferential
path the pigtail slack exhibits additional slack. The additional
slack may be taken up using slack-half loops 154 in the vertical
channel where the pigtails are routed. The random nature of
connecting splitter output pigtails to subscriber ports may result
in a family of various size half-loops 154 that are managed in the
vertical channel within the confines of the cabinet.
[0040] FIGS. 5A and 5B schematically illustrate the installation of
the optical splitter module pigtails and the service connection
configuration of the optical splitter module, respectively, in a
network having modules adjacent to each other in accordance with a
preferred embodiment of the present invention. A preferred
embodiment of the present invention includes a method to connect
subscriber ports that are in an adjacent field but not initially
contained within the circumference of the splitter pigtail harness.
In this extension the splitter output pigtail is routed to the
adjacent field which by virtue of a juxtaposed position has a path
at the same distance to the subscriber port within the
circumference. The subscriber ports in the adjacent field also are
assigned randomly therefore the resultant slack is managed using a
family of various size half-loops in the vertical channel 176.
[0041] FIGS. 5C and 5D schematically illustrate the service
connection configurations 194, 206 of the termination and splitter
fields in adjacent fiber distribution hubs in accordance with a
preferred embodiment of the present invention. The pigtails 198,
208 of the left module 196, 214 are routed circumferentially
clockwise while the right pigtails 204, 210 of the module 202, 216
are routed circumferentially counterclockwise in a preferred
embodiment. The fiber distribution hubs in this embodiment are
located adjacent to one another, each having a splitter shelf with
splitter modules and a termination shelf. The counter rotating feed
provide for routing of the splitter module output pigtails
circumferentially around the subscriber termination fields. The
pigtail slack is stored in the vertical channels 200, 212.
[0042] A preferred embodiment includes a method of removing a
splitter pigtail from a subscriber port and either redeploying that
output pigtail to a new subscriber or storing the pigtail back to
the original storage position at the splitter module. The method is
completely non-blocking and non-congesting due to the planned slack
management.
[0043] FIG. 6 is a flow chart illustrating a method for installing
and connecting optical splitter module pigtails in accordance with
a preferred embodiment of the present invention. The method
includes the step 222 of installing a splitter module with output
pigtails in a patch panel position. Further, the method includes
the step 224 of routing the splitter module output pigtails
circumferentially around a subscriber termination field. The method
includes the step 226 of connecting an individual splitter pigtail
connectorized ends at splitter module storage receptacles. These
storage receptacles can be initially preconditioned in the factory.
The method includes a next step 228 of storing the pigtail slack in
half-loops in an adjacent vertical channel. Further, the method
includes the step 230 of deciding whether to connect or disconnect
the service order. If a service order needs to be connected, the
method includes the decision in step 232 of determining if a
splitter output is available for assignment. If it is determined
that the splitter output is available for assignment then the
method progresses to step 242 of disengaging connectorized pigtail
from the storage position. If it is determined that the splitter
output is not available per step 238 then it is determined if a
position is available for adding a module. If yes, then the method
steps are reiterated starting back from step 222. If, however, it
is determined that there is no position available then the maximum
module capacity of the system has been reached.
[0044] The method also includes the option of disconnecting the
service order per step 234. The step 234 includes disengaging the
connectorized pigtail from the subscriber position and per step 236
routing the pigtail through an expanded circumferential path around
the subscriber termination field 236.
[0045] The method further includes the step 244 of connecting the
splitter pigtail to the subscriber position and the step 246 of
routing the pigtail through a reduced circumferential path around
the subscriber termination field. The method includes the step 248
of storing the pigtail slack in graduated half-loops in an adjacent
vertical channel.
[0046] FIGS. 7A-7E illustrate views of a fiber distribution hub in
accordance with a preferred embodiment of the present invention.
The fiber distribution hub (FDH) in accordance with a preferred
embodiment administers connections between fiber optic cables and
passive optical splitters in the outside plant (OSP) environment.
These enclosures are used to connect feeder and distribution cables
via power splitters providing distributed service in a FTTP network
application. The preferred embodiment FDH provides a vital
cross-connect/interconnect interface for optical transmission
signals at a location in the network where fiber hubbing,
operational access and reconfiguration are important requirements.
In addition the FDH is designed to accommodate a range of sizes and
fiber counts and support factory installation of pigtails, fanouts
and splitters.
[0047] In a preferred embodiment, the FDH enclosure is designed for
front access via a two-door configuration (FIG. 7E). The FDH
provides termination, splicing, interconnection and splitting in
one compartment. The unit accommodates either metallic or
dielectric OSP cables via sealed grommet entry. Cables are secured
with standard grip clamps. The FDH provides grounding for metallic
members and for the cabinet.
[0048] The enclosure provides environmental and mechanical
protection for cables, splices, connectors and passive optical
splitters. These heavy gauge aluminum enclosures are NEMA-4.times.
rated and provide the necessary protection against rain, wind,
dust, rodents and other environmental contaminants. At the same
time, they remain lightweight for easy installation, and breathable
to prevent accumulation of moisture in the unit. The aluminum
construction with a heavy power coat finish also provides for
corrosion resistance. The enclosure is accessible through secure
doors that are locked with standard tool or pad-lock.
[0049] In accordance with preferred embodiments, the FDH is
provided in pole mount or pedestal mount configurations. The same
cabinet and working space is available in both pole mount (FIGS. 7A
and 7B) and pedestal mount units (FIGS. 7C, 7D and 7E). Three sizes
of the fiber distribution hubs are available, for example, to
correspond to three different feeder counts, for example, 144, 216
and 432.
[0050] FIG. 8 illustrates a view of the internal components of a
fiber distribution hub enclosure 350 in accordance with a preferred
embodiment of the present invention. The FDH enclosure 350 can be
configured in a number of different ways to support fiber cable
termination and interconnection to passive optical splitters. The
configuration illustrated in the preferred embodiment provides for
a termination shelf 352, a splitter shelf and optical component
modules 354 and a channel for fiber management 358.
[0051] The termination shelf 352 can be based on the standard main
distribution center (MDC) enclosure line that provides complete
management for fiber terminations in accordance with a preferred
embodiment of the present invention. In a preferred embodiment, the
termination shelf is preterminated in the factory with a stub cable
containing either 144-fibers, 216-fibers or 432-fibers. This stub
cable is used to connect services to distribution cables routed to
residences. The distribution fibers are terminated on certified
connectors. The termination shelf uses standard 12-pack or 18-pack
adapter panels, for example, that have been ergonomically designed
to provide easy access to fiber terminations in the field. The
panels can be mounted on a hinged bulkhead to allow easy access to
the rear for maintenance. The fiber jumpers are organized and
protected as they transition into the fiber management section 358
of the enclosure.
[0052] The splitter shelf 354 can be based on a standard fiber
patch panel that accepts standard optical component modules (OCM)
holding optical splitters in accordance with a preferred embodiment
of the present invention. In a preferred embodiment, the splitter
cassettes are designed to simply snap into the shelf and therefore
can be added incrementally as needed. The splitter shelf serves to
protect and organize the input and output fibers connected to the
cassettes. Splitter shelves are available in various sizes and the
shelf size can be optimized for different OCM module
configurations.
[0053] FIG. 9 illustrates a schematic view of a fiber distribution
hub enclosure 380 having a side-by-side equipment configuration in
accordance with a preferred embodiment of the present invention.
There are two adjacent termination shelves 388, 390 and two
adjacent splitter shelves 384, 386, separated by a central fiber
management channel 382 in accordance with a preferred embodiment of
the present invention.
[0054] FIG. 10 illustrates a view of the optical component modules
in a fiber distribution hub enclosure in accordance with a
preferred embodiment of the present invention. The FDH
configuration in a preferred embodiment provides for fiber
management hardware on one side of the cabinet. This allows fiber
jumpers to be routed between the termination shelf and the splitter
shelf. Excess slack can be managed on the side of the cabinet using
slack loops.
[0055] In accordance with a preferred embodiment, OCM modules can
also be equipped with pigtails to reduce the number of connections
in the network. The module shown in FIG. 10 contains a 1.times.32
splitter with pigtails provided on the input and 32 outputs. The
connectorized ends of the pigtails are stored on bulkhead adapters
on the front of the module. These storage adapters provide a
familiar locating scheme for spare pigtails so that connector ends
can be quickly identified and connected to distribution fibers. The
spacing on the adapters is the same as on standard connector
panels.
[0056] In preferred embodiments, OCM modules can also be equipped
with standard terminators. Modules terminated with bulkhead
adapters may be equipped with terminators on the front of the
module. Modules connected via pigtails and equipped with storage
adapters are equipped with terminators on the rear of the
panel.
[0057] The claims should not be read as limited to the described
order or elements unless stated to that effect. Therefore, all
embodiments that come within the scope and spirit of the following
claims and equivalents thereto are claimed as the invention.
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