# Patent

## Title
Transition box for multiple dwelling unit fiber optic distribution network

## Abstract

A transition box for a fiber optic network for a multiple distribution unit (MDU) is disclosed. The transition box comprises an enclosure a fiber optic adapter removably mounted in the enclosure. The fiber optic adapter is configured to receive one or more optical fibers of a riser cable to provide optical communication service from a service provider to a subscriber premises. A payout reel removably mounted in the enclosure stores slack of the riser cable paid out to at least one of one or more distribution levels in the MDU.

## Background
RELATED APPLICATIONS
This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application Ser. No. 61/530,662 filed on Sep. 2, 2011 the content of which is relied upon and incorporated herein by reference in its entirety.
This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application Ser. No. 61/447,600 filed on Feb. 28, 2011 the content of which is relied upon and incorporated herein by reference in its entirety.
This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application Ser. No. 61/440,214 filed on Feb. 7, 2011 the content of which is relied upon and incorporated herein by reference in its entirety.
This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application Ser. No. 61/394,658 filed on Oct. 19, 2010 the content of which is relied upon and incorporated herein by reference in its entirety.


BACKGROUND
Field of the Disclosure
The technology of the disclosure relates to a fiber optic distribution network solutions for indoor applications, particularly for multiple dwelling units. The fiber optic network solution can include a transition box that provides a termination and slack storage point to transition from a vertical run riser cable to a drop cable that feeds multiple users on a distribution level of the multiple dwelling unit and to transition from vertical run riser cable to a distribution cable that optically connects to a feeder cable through a local convergence point at a lower level of the MDU.
Technical Background
In the world of the ever-increasing need for broadband bandwidth optical cables have become the main part of telecommunication networks. Optical cables can transmit voice signals, data signals and video signals for very long distances with very high speed. Developments of optic telecommunication networks allow the connection of the end user directly to the optical fiber. This kind of network technology known as FTTH technology (fiber to the home) requires extending an “all optical” communication network closer to the subscribers. As a result such telecommunication networks include large number distribution points from a distribution cable to an end user or subscriber.
One of the key parts of the FTTH network is the last mile connection which often is an indoor installation. Different kinds of buildings like multiple dwelling units and apartments require complicated cabling systems which might mean that there are many separated cables, each one to connect one subscriber. Installation of many cables which provide the connection between a main distribution point (which usually is located in the basement or in another place of the building) and the end user may cause many problems with routing through the wall or levels of the building. As a result, such installations consume a lot of time and costs.
SUMMARY
Embodiments disclosed in the detailed description include a transition box for a fiber optic network for a multiple distribution unit (MDU). The transition box comprises an enclosure and a fiber optic adapter removably mounted in the enclosure. The fiber optic adapter is configured to receive one or more optical fibers of a riser cable to provide optical communication service from a service provider to a subscriber premises. A payout reel removably mounted in the enclosure stores slack of the riser cable paid out to extend to at least one of one or more distribution levels in the MDU.
In another embodiment, a transition box for a fiber optic network for a multiple distribution unit (MDU) having an enclosure and a module removable mounted in the enclosure is disclosed. A fiber optic adapter assembly is pivotably mounted in the module. The fiber optic adapter assembly has at least one multi-fiber adapter and at least one single fiber adapter. A riser cable optically connects at the fiber optic adapter assembly to provide optical communication service to a subscriber premises. A payout reel removably mounted in the enclosure stores slack of the riser cable paid out to extend to at least one of one or more distribution levels in the MDU.



BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a schematic diagram of a perspective elevation view of a multiple dwelling unit (MDU) with an exemplary fiber optic network installed therein, wherein a riser cable with pre-set tap points extends from a payout reel in a patch panel enclosure located at a lower level to multiple distribution levels;
FIG. 2 is a schematic diagram of a perspective elevation view of a MDU with an exemplary fiber optic network installed therein, wherein a riser cable with pre-set tap points extends from a payout reel in a slack enclosure on a distribution level and extends to other distribution levels and/or to a lower level;
FIG. 3 is a schematic diagram of a perspective elevation view of a MDU with an exemplary fiber optic network installed therein, wherein a riser cable with pre-set tap points extends from a payout reel in a FDT on a distribution level to other distribution levels and the lower level via a patch panel;
FIG. 4 is a schematic diagram of a perspective elevation view of a MDU with an exemplary fiber optic network installed therein, wherein a plurality of riser cables each extend from a separate payout reel in a patch panel enclosure located at the lower level to one of the distribution levels;
FIG. 5 is a schematic diagram of a perspective elevation view of a MDU with an exemplary fiber optic network installed therein, wherein a plurality of riser cables each extend from a separate FDTs each located at one of the distribution levels to the patch panel enclosure located at the lower level;
FIG. 6 is a schematic diagram of a bundled drop cable extending from a FDT to a subscriber premises located on a distribution level of the MDU;
FIG. 7 is a schematic diagram of an elevation view of an exemplary preconnectorized riser cable installation assembly with a plurality of preconnectorized riser cables being extended from payout reels located at a lower level by a leader with extending features attached to the leader at preset locations;
FIG. 7A is a detail view of an exemplary pull device assembly which may be attached to the end of the riser cable to facilitate extending the riser cable from the payout reel;
FIG. 8 is a flowchart illustrating a method of installing a plurality of preconnectorized riser cables from payout reels located at a lower level to FDTs located at distribution levels, according to an exemplary embodiment;
FIG. 9 is a schematic diagram of an elevation view of an exemplary preconnectorized riser cable installation assembly with a plurality of preconnectorized risers being extended from payout reels located at distribution levels by a leader with extending features attached to the leader at preset locations;
FIG. 10 is a flowchart illustrating a method of installing a plurality of preconnectorized riser cables from payout reels located at distribution levels to a patch panel enclosure located at the lower level, according to an exemplary embodiment;
FIG. 11 is a schematic diagram of a front, perspective view of an exemplary local convergence point (LCP) for use with a fiber optic network in a MDU;
FIG. 11A is a schematic diagram of a front, perspective exploded view of the LCP of FIG. 11 having an interior panel removably mountable in the LCP, wherein the interior panel is configured to support optical fiber in a first section of the LCP;
FIG. 11B is a schematic diagram of a front, perspective exploded view of the LCP of FIG. 11 having an interior panel removably mountable in the LCP, wherein the interior panel is configured to support optical fiber splitting in the second section of the LCP;
FIG. 11C is a schematic diagram of a front, perspective exploded view of the LCP of FIG. 11 having an interior panel removably mountable in the LCP, wherein the interior panel is configured to support optical fiber splicing in the second section of the LCP;
FIG. 12 is a schematic diagram of front, elevation views of an exemplary transition box with a multi-fiber adapter assembly and multiple payout reels removably mounted therein;
FIG. 13 is a schematic diagram of a front, perspective view of an exemplary FDT having a module with multi-fiber adapters and a panel with single fiber adapters and a payout reel removably mounted therein, wherein the FDT is configured to be mounted in-line with and supported by the conduit carrying the riser cable;
FIG. 14 is a schematic diagram of a front, perspective view of an exemplary FDT having a module assembly with multi-fiber adapters and single fiber adapters pivotably mounted therein and a collapsible payout reel removably mounted therein, wherein the FDT is configured to be wall or closet mounted; and
FIG. 15 is a schematic diagram of the front, perspective view of the FDT of FIG. 14 with the module assembly pivoted to an open position;
FIG. 16 is a schematic diagram of a front, perspective view of the interior of a transition box with a chamber wall that divides the interior between a dry side and a wet side;
FIG. 17 is a schematic diagram of the transition box of FIG. 16 with a fiber optic cable having a drip loop illustrated therein.



DESCRIPTION OF THE DISCLOSURE
Embodiments disclosed in the detailed description include a fiber optic distribution network for a multi-floor multiple dwelling unit (MDU). The network includes a local convergence point (LCP) which may be located in a lower level of the MDU, for example, the basement. The LCP receives a feeder cable that provides optical communication service to the MDU from a service provider. One or more preconnectorized riser cables having multi-fiber connectors on each end optically connect to the feeder cable through the LCP. The riser cable extends from the LCP to one or more upper distribution levels of the MDU. At the distribution level, the riser cable is received by a network access point, which may be comprised of a fiber distribution terminal (FDT), a mid-span access point, or the like. For purposes herein, the terms network access point may be used to describe either one or more of the FDT and the mid-span access point. Additionally, it should be understood that the terms FDT, pipe-in-box, and closet box will be used to refer and describe a component of the fiber optic distribution network located at the distribution level for optically connecting the riser cable to the drop cable. The term patch panel enclosure will be used when describing the component of the fiber optic distribution network for optically connecting and extending the riser cable to the LCP and, thereby, to the feeder cable.
Optically connecting the riser cable and to the subscriber premises may be through tether cables branched off from the riser cable at each distribution level, for example, at a mid-span access point of the riser cable. The tether cables may be connected to subscriber premises via one or more drop cables at the network access point. Alternatively, or additionally, an individual riser cable may be extended to the distribution level and optically connect to one or more drop cables routed to the subscriber premises. In such case, a tether cable may not be branched off of the riser cable at a mid-span access point. The drop cable extends to the subscriber premises at the distribution level to provide optical communication service to the subscriber. Any riser cable slack may be stored in the FDT, the patch panel enclosure, and/or a separate slack enclosure. Additionally, the riser cable slack may be stored on the payout reel, with the payout reel removably mounted in the FDT, the patch panel enclosure, or the slack enclosure. The slack enclosure may be located at or adjacent to the LCP or at one or more of the distribution levels.
The end of the riser cable would optically connect to the end of one or more drop cables. In either case, the tether cable and/or the riser cable may terminate in a fiber optic connector and optically connect to the drop cable terminated in a fiber optic connector through a suitable fiber optic adapter. The fiber optic adapter may be one that provides for multi-fiber connector to multi-fiber connector interconnection, such as, for example an MTP adapter, or other types of multi-fiber adapters. Additionally or alternatively, the fiber optic adapter may be one that provides for single fiber connector to single fiber connector interconnection, for example an SC adapter, or other types of single fiber adapters. The fiber optic adapters may have dual shutters, one on each end of the adapter. The shutters are adapted to automatically close against the end of the adapter when a fiber optic connector is not inserted in that end of the adapter. In this manner, the shutters may provide sealing of the adapter against the environment, keeping the adapter protected and clean when not in use. The adapter may be keyed up and down to coordinate with the polarity of the connectors. The adapters may be mounted in a cassette or module which is removably mounted in the network access point. Alternatively, the adapter may be removably mounted to a panel which may be removably mounted in the network access point.
As such, the FDT and/or the patch panel enclosure may act as or be a transition box having one or more removably mounted fiber optic adapters configured to receive one or more optical fibers of a riser cable to provide optical communication service from a service provider to a subscriber premises. Additionally, the transition box may have one or more removably mounted payout reels storing the slack of the riser cable or cables paid out in the MDU.
In this regard, FIGS. 1-6 illustrate exemplary embodiments of fiber optic networks in an MDU 10. FIG. 1 is a schematic diagram of a perspective elevation view of the MDU 10 with an exemplary fiber optic network 12 installed therein. A riser cable 14 with pre-set mid-span access points 16 extends from a payout reel 18. The mid-span access point 16 may comprise a FlexNAP System, as commercially available from Corning Cable Systems LLC, or other type of connection or system that provides for the separation of one or more optical fibers from the riser cable 14. The riser cable 14 pays out from a payout reel 18. Once the riser cable 14 is paid out from the payout reel 18 to multiple distribution levels 24, 26, 28, the payout reel 18 is removably mounted in a patch panel enclosure 20. Although, in FIG. 1 three higher levels 24, 26, 28 are illustrated, the fiber optic network 12 may have any number of distribution levels. The riser cable 14 is preconnectorized with multi-fiber connectors 30, 32 at each end of the riser cable 14. The patch panel enclosure 20 has a multi-fiber-to-multi-fiber adapter assembly 34 which receives a first multi-fiber connector 30. A distribution cable 36 preconnectorized with a multi-fiber connector 38, is received by and connects to the multi-fiber adapter assembly 34 in the patch panel enclosure 20 to establish an optical connection between the riser cable 14 and the distribution cable 36. The distribution cable 36 routes to a local convergence point (LCP) 40. The LCP 40 receives a feeder cable 42 which provides optical communication service to the MDU 10 from a service provider.
During installation, the riser cable 14 pays out from the payout reel 18 such that the riser cable 14 extends generally in an upward direction from the lower level 22 to each ascending distribution level 24, 26 in succession with distribution level 28 being the highest distribution level in the MDU 10. The mid-span access points 16 are preset such that they are separated by a distance “X” along the length of the riser cable 14. The distance “X” is preset at the factory to a certain value depending on the distance between adjoining distribution levels 24, 26. As examples, the distance “X” may be set at any desired distance, as examples, 10 feet, 12 feet, 14 feet, 15 feet, and the like. In this manner, as the riser cable 14 pays out and installed in the MDU 10, the preset mid-span access points will align, generally, with each distribution level 24, 26, 28 of the MDU 10. However, the one exception to this may be the highest distribution level 28, since the end of the riser cable 14 would extend to that level and would not have a mid-span access point. Any riser cable 14 slack due to the presetting of the distance “X” or otherwise, may be stored on the payout reel 18, in the patch panel enclosure 20 and/or a slack enclosure (not shown in FIG. 1). Slack may also be stored loosely at the lower level 22, and/or in one or more fiber distribution terminals 29 located at one or more of the distribution levels 24, 26, 28. Additionally, the payout reel 18 may be removably mounted in the slack housing or may be mounted or located separate from the patch panel enclosure 20 and/or slack enclosure and/or from the FDT 29 at one or more of the distribution levels 24, 26, 28.
The riser cable 14 may be any number of optical fibers, as non-limiting examples, 6-216 fibers. At each mid-span access point 16, certain ones of the optical fibers may be separated or furcated out from the riser cable 14 in a FDT 29 located at the distribution level 24, 26. As non-limiting examples, 6, 8 or 12 fibers may be furcated out from the riser cable 14 and terminated with the second multi-fiber connector 32. At the highest distribution level 28, the optical fibers remaining in the riser cable 14 after furcating out the optical fibers at lower distribution levels 24, 26 are terminated with the second multi-fiber connector 32. The second multi-fiber connector 32 may be received by a multi-fiber adapter assembly 34 removably mounted in the FDT 29 at the distribution level 24, 26, 28. The multi-fiber adapter assembly 34 may removably mounted in a connector module (not shown in FIG. 1), which may be removably mounted in the FDT 29.
A multi-fiber bundled drop cable 44 preconnectorized with a multi-fiber connector 38, is received by and connects to the multi-fiber adapter assembly 34, or the connector module, as the case may be, in the FDT 29 located at the distribution reel 24, 26, 28. In this manner an optical connection is established between the riser cable 14 and the multi-fiber bundled drop cable 44. The multi-fiber bundled drop cable 44 routes to one or more drop boxes 46 associated with subscriber premises 48 located at the distribution level 24, 26, 28. One or more optical fiber separates from the multi-fiber bundled drop cable 44 at the drop box 46 and extends to the subscriber premises 48. In this manner, optical communication service is provided to the subscriber premises 48.
Alternatively or additionally, one or more connectorized harnesses may be connected between the multi-fiber adapters in the multi-fiber adapter assembly 34 and extended to single fiber adapters (not shown in FIG. 1). In such a case, connectorized single fiber drop cables may connect to the harnesses to establish optical connection with the riser cable 14, and ultimately to the subscriber premises 48.
FIG. 2 is a schematic diagram of a perspective elevation view the MDU 10 with an exemplary fiber optic network 112 installed therein. The riser cable 14 with pre-set mid-span access points 16 extends from a payout reel 18 in a separate slack enclosure 50 located at the highest distribution level 28 to the other distribution levels 24, 26 and the lower level 22. The fiber optic network 112 is similar to fiber optic network 12 shown on FIG. 1, and, therefore, the aspects and/or components of the fiber optic network 112 described with respect to FIG. 1 will not be described again with respect to FIG. 2. In FIG. 2, after the riser cable 14 is paid out, the payout reel 18 is removably mounted in the slack enclosure 50 located at the highest level 28 instead of the patch panel enclosure 20. In this manner, during installation, the riser cable 14 pays out from the payout reel 18 such that the riser cable 14 extends generally in a downward direction from the highest distribution level 28 to each descending distribution level 24, 26 in succession, and to the patch panel enclosure 20.
The patch panel enclosure 20 includes a multi-fiber adapter assembly 34 but may not include the payout reel 18 since that is located at the highest distribution level 28 in fiber optic network 112. However, the multi-fiber adapter assembly 34 in the patch panel enclosure 20 receives the first multi-fiber connector 30 and optically connects it with the multi-fiber connector 38 of the distribution cable 36 to establish an optical connection between the riser cable 14 and the distribution cable 36 as described above with respect to FIG. 1.
FIG. 3 is a schematic diagram of a perspective elevation view of the MDU 10 with an exemplary fiber optic network 212 installed therein. The riser cable 14 with pre-set mid-span access points 16 extends from the payout reel 18 in the FDT 29 located at the highest distribution level 28 to the other distribution levels 24, 26. The fiber optic network 212 is similar to fiber optic network 12 shown on FIG. 1 and the fiber optic network 112 shown on FIG. 2 and, therefore, the aspects and/or components of the fiber optic network 212 described with respect to FIG. 1 and/or FIG. 2 will not be described again with respect to FIG. 3. In FIG. 3, after the riser cable 14 is paid out, the payout reel 18 is removably mounted in the FDT 29 located at the highest distribution level 28 instead of the slack enclosure 50, as described with respect to FIG. 2. In this way, the slack enclosure 50 is not needed at the highest distribution level 28 conserving space. The paying out and installation of the riser cable 14 may be the same as described with respect to FIG. 2.
FIG. 4 is a schematic diagram of a perspective elevation view of the MDU 10 with an exemplary fiber optic network 312 installed therein. A plurality of riser cables 14(1), 14(2), 14(3) each extend from a separate payout reel 18(1), 18(2), 18(3) in the patch panel enclosure 20 and extending to respective ones of the distribution levels 24, 26, 28. Each riser cable 14(1), 14(2), 14(3) pays out from respective payout reels 18(1), 18(2), 18(3). After the riser cable 14(1), 14(2), 14(3) is paid out, the respective payout reel 18(1), 18(2), 18(3) is removably mounted in the patch panel enclosure 20. The riser cables 14(1), 14(2), 14(3) extend generally in an upward direction from the lower level 22 to separate ascending distribution level 24, 26, 28. In this manner, a separate riser cable 14 provides optical service to a separate distribution level 24, 26, 28. Each of the riser cables 14(1), 14(2), 14(3) terminates with respective second multi-fiber connectors 32 which are received by and connected to the respective multi-fiber adapter assembly 34 in the FDT 29 located at the distribution levels 24, 26, 28. In the patch panel enclosure 20, the riser cables 14(1), 14(2), 14(3) extend from each of the payout reels 18(1), 18(2), 18(3) to the multi-fiber adapter assembly 34 located at the patch panel enclosure 20. The first multi-fiber connector 30 of each respective riser cable 14(1), 14(2), 14(3) is received by and connects to the multi-fiber adapter assembly 34 in the patch panel enclosure 20. The distribution cable 36 preconnectorized with a multi-fiber connector 38, is received by and connects to the multi-fiber adapter assembly 34 in the patch panel enclosure 20 to establish an optical connection between the riser cables 14(1), 14(2), 14(3) and the distribution cable 36. The distribution cable 36 routes to the LCP 40.
FIG. 5 is a schematic diagram of a perspective elevation view of the MDU 10 with an exemplary fiber optic network 412 installed therein. The plurality of riser cables 14(1), 14(2), 14(3) each extend from separate, respective FDTs 29 located on one of the distribution levels 24, 26, 28 to the patch panel enclosure 20. The fiber optic network 412 is similar to fiber optic network 312 shown on FIG. 4, and, therefore, the aspects and/or components of the fiber optic network 312 described with respect to FIG. 4 will not be described again with respect to FIG. 5. Each riser cable 14(1), 14(2), 14(3) pays out from respective payout reels 18(1), 18(2), 18(3). After the necessary length of riser cable 14(1), 14(2), 14(3) is paid out, the payout reel 18(1), 18(2), 18(3) is removably mounted in separate, respective FDTS 29 located at respective distribution levels 24, 26, 28. The riser cables 14(1), 14(2), 14(3) extend generally in a downward direction from the respective FDTs 29 located at respective distribution levels 24, 26, 28 to the lower level 22. In this manner, a separate riser cable 14 provides optical service to a separate distribution level 24, 26, 28. Each of the riser cables 14(1), 14(2), 14(3) terminates with respective second multi-fiber connectors 32(1), 32(2), 32(3) which are received by and connected to the respective multi-fiber adapter assembly 34 in the FDT 29 located at the distribution levels 24, 26, 28. In the patch panel enclosure 20, the first multi-fiber connector 30(1), 30(2), 30(3) of each respective riser cable 14(1), 14(2), 14(3) is received by and connects to the multi-fiber adapter assembly 34 in the patch panel enclosure 20. The distribution cable 36 preconnectorized with a multi-fiber connector 38, is received by and connects to the multi-fiber adapter assembly 34 in the patch panel enclosure 20 to establish an optical connection between the riser cables 14(1), 14(2), 14(3) and the distribution cable 36. The distribution cable 36 routes to the LCP 40.
Referring now to FIG. 6, the portion of the fiber optic networks 12, 112, 212, 312, 412 at the distribution level 24, 26, 28 is illustrated. The multi-fiber bundled drop cable 44 extends from the FDT 29 at the distribution level 24, 26, 28 to drop box 46 associated with and located at the subscriber premises 48. The multi-fiber bundled drop cable 44 includes multiple fiber optic cables 52 retained together by one or more helically wrapped external binders 54. One or more of the multiple fiber optic cables is separated from the multi-fiber bundled drop cable 44 by removing the multiple fiber optic cable from the retainage of the one or more external binders. The separated fiber optic cable 52 may then extend to the subscriber premises 48.
FIG. 7 is a schematic diagram of an elevation view of an exemplary preconnectorized riser installation assembly 56 with a plurality of preconnectorized riser cables 14(1), 14(2), 14(3) being extended from respective payout reels 18(1), 18(2), 18(3) located at a lower level 22 by a leader 58 with extending features 60 attached to the leader 58 at preset locations at a distance “Y” along the length of the leader 58. The extending feature 60 may be any type of loop, hook, swivel, or the like, configured to attach to the second multi-fiber connectors 32(1), 32(2), 32(3), or to some type of pull device attached to the second multi-fiber connectors 32(1), 32(2), 32(3) to provide for safely and effectively paying out the riser cables 14(1), 14(2), 14(3).
FIG. 7A is a detail view of a pull device assembly 62 which may be attached to the end of the riser cable 14 to facilitate extending the riser cable 14 from the payout reel 18. The pull device assembly 62 attaches to the riser cable 14 around the second multi-fiber connector 32 enclosing the second multi-fiber connector 32, boot and a portion of the riser cable 14. The pull device assembly 62 has a swivel end 64 and a body 66. The body 66 may enclose and/or support the second multi-fiber connectors 32. The swivel end 64 is allowed to rotate freely and independently of the body 66 and, therefore, the second multi-fiber connector 32 and the riser cable 14. The swivel end 64 comprises a hole through which the extending feature 60 inserts. As the riser cable 14 is pulled through the MDU 10 particularly in conduit using a pull loop 68 attached to the end of the leader 58, and the extending feature 60 attached to the swivel end 64, the swivel end 64 it is allowed to independently rotate from the rest of the pull device assembly 62. This independent rotation eliminates twisting of the riser cable 14 and the second multi-fiber connector 32. In this manner, as the leader 58 is pulled through the MDU 10 particularly in conduit, the leader 58, the extending feature 60 and the swivel end 64 reduce or may eliminate any induce additional torsional stresses on the riser cable 14 and/or the second multi-fiber connector 32.
Referring again to FIG. 7, the distance “Y” is preset to a certain value depending on the distance between adjoining distribution levels 24, 26, 28. As examples, the distance “Y” may be set at 10 feet, 12 feet, 14 feet, 15 feet, and the like. In this manner, as the leader 58 is pulled through the MDU 10, riser cables 14(1), 14(2), 14(3) each pays out to a point that will align, generally, with each respective distribution level 24, 26, 28 of the MDU 10. Any riser cable 14 slack due to the presetting of the distance “Y” or otherwise, may be stored on the respective payout reel 18(1), 18(2), 18(3) and/or loosely in an patch panel enclosure 20 and/or a slack enclosure (not shown in FIG. 7). Additionally, slack may be stored loosely, on the payout reels 18(1), 18(2), 18(3) and/or the FDT 29 at one or more of the distribution levels 24, 26, 28. Each second multi-fiber connectors 32(1), 32(2), 32(3), may then be connected to the respective multi-fiber adapter assembly 34 removably mounted in the FDT 29 located at the respective distribution level 24, 26, 28. Additionally, the first multi-fiber connectors 30(1), 30(2), 30(3) attached to respective riser cables 14(1), 14(2), 14(3) may be connected to the respective multi-fiber adapter assembly 34 removably mounted in the patch panel enclosure 20.
FIG. 8 is a flowchart illustrating a method of installing a plurality of preconnectorized riser cables 14(1), 14(2), 14(3), from payout reels 18(1), 18(2), 18(3) located at a lower level 22 to FDTs 29 located at upper levels 24, 26, 28 according to an exemplary embodiment. The payout reels 14(1), 14(2), 14(3) are positioned in the lower level 22 (Step 1000). Optionally, a pull device assembly 62 may be attached to the end of each riser cable 14(1), 14(2), 14(3) (Step 1002). A leader 58 with extending features 60 located at the pre-set distance “Y” along the length of the leader 58 is provided (Step 1004). The extending features 60 are attached to the end of each riser cable 14(1), 14(2), 14(3), particularly to each pull device assembly 62 if such is provided (Step 1006). A pull rope is attached to the end of the leader 58 through a pull loop 68 (Step 1008) and, using the pull rope, the leader 58 is pulled to the distribution levels 24, 26, 28 of the MDU 10 in an ascending order paying out the riser cables 14(1), 14(2), 14(3) from the respective payout reels 18(1), 18(2), 18(3) (Step 1010). At each successive distribution level 24, 26, 28 in the ascending order, the leader 58 is accessed and the appropriate riser cable 14(1), 14(2), 14(3) for that distribution level 24, 26, 28 is extended. The appropriate riser cable 14(1), 14(2), 14(3) is disconnected from the extending feature 60 and the second multi-fiber connector 32(1), 32(2), 32(3) to the respective multi-fiber adapter assembly 34 in the FDT 29 at the distribution level 24, 26, 28 (Step 1012). The first multi-fiber connectors 30(1), 30(2), 30(3) may be connected to the multi-fiber adapter assembly 34 located in the patch panel enclosure 20 (Step 1014). Riser cable 14 slack may be stored in the FDT 29 at the distribution level 24, 26, 28 and/or in the payout reels 18(1), 18(2),18(3) (Step 1016). The payout reels 18(1), 18(2),18(3) may be removably mounted in the patch panel enclosure 20.
FIG. 9 is a schematic diagram of an elevation view of an exemplary preconnectorized riser installation assembly 70 with a plurality of preconnectorized riser cables 14(1), 14(2), 14(3) being extended from payout reels 18(1), 18(2), 18(3) each located at respective distribution levels 24, 26, 28 of the MDU 10. The riser cables 14(1), 14(2), 14(3) by a leader 58 with extending features 60 attached to the leader 58 at preset locations at a distance “Z” along the length of the leader 58. The extending feature 60 may be any type of loop, hook, swivel, or the like, configured to attach to the second multi-fiber connectors 32(1), 32(2), 32(3), or to some type of pull device attached to the second multi-fiber connectors 32(1), 32(2), 32(3) to provide for safely and effectively paying out the riser cables 14(1), 14(2), 14(3). The pull device assembly 66 described with respect to FIG. 7A, above, may be attached to the end of the riser cables 14(1), 14(2), 14(3) to facilitate extending the riser cables 14(1), 14(2), 14(3) from the payout reels 18(1), 18(2),18(3).
The distance “Z” is preset to a value, as a nonlimiting example, 6 inches, to allow the leader 58 to be accessed at each succeeding distribution level 24, 26, 28 in descending order to attach extending feature 60 to the particular riser cable 14(1), 14(2), 14(3). In other words, the riser cable 14(3) for the highest distribution level 28 is attached to the leader first. Then the riser cable 14(2) for then next lower distribution level 26 is attached to the leader 58. Then the riser cable 14(1) for the next lower distribution level 24 is attached to the leader 58. The leader 58 extends to the lower level 22. Any riser cable 14 slack may be stored on the respective payout reel 18(1), 18(2), 18(3) and/or loosely in the FDT 29 and/or a slack enclosure (not shown in FIG. 9) at the distribution level 24, 26, 28. Additionally, slack may be stored in the patch panel enclosure 20. Each second multi-fiber connectors 32(1), 32(2), 32(3), may then be connected to the respective multi-fiber adapter assembly 34 removably mounted in the FDT 29 located at the respective distribution level 24, 26, 28. Additionally, the first multi-fiber connectors 30(1), 30(2), 30(3) attached to respective riser cables 14(1), 14(2), 14(3) may be connected to the respective multi-fiber adapter assembly 34 removably mounted in the patch panel enclosure 20.
FIG. 10 is a flowchart illustrating a method of installing a plurality of preconnectorized riser cables 14(1), 14(2), 14(3) from payout reels 18(1), 18(2), 18(3) located at distribution levels 24, 26, 28 of MDU 10 to the patch panel enclosure 20, according to an exemplary embodiment. The payout reels 14(1), 14(2), 14(3) are each positioned at respective distribution levels 24, 26, 28 (Step 2000). Optionally, a pull device assembly 62 may be attached to the end of each riser cable 14(1), 14(2), 14(3) (Step 2002). A leader 58 with extending features 60 located at the pre-set distance “Z” along the length of the leader 58 is provided (Step 2004). A pull rope is attached to the pulling loop 68 at the end of the leader 58 (Step 2006). One of the extending features 60, which may be the first extending feature 60 closest to the pulling loop 68 is attached to the riser cable 14(3) from the payout reel 18(3) located at the highest distribution level 28 in the MDU 10 (Step 2008). The leader 58 is extended to the next succeeding distribution level 26, 24 in descending order (Step 2010). At the next succeeding distribution level 26, 24, the leader 58 is accessed and the next extending feature 60 is attached to the end of that riser cable 14(2), 14(3) (Step 2012). The leader 58 is extended to all of the distribution levels and the riser cable attached in the same manner. The leader 58 is extended to the lower level 22 (Step 2014). The riser cables 14(1), 14(2), 14(3) are disconnected from the leader 58 and each first multi-fiber connector 30(1), 30(2), 30(3) is connected to the multi-fiber adapter assembly 34 in the patch panel 20 enclosure (Step 2016). Each second multi-fiber connector 32(1), 32(2), 32(3) is connected to respective multi-fiber adapter assemblies 34 in the FDT 29 located at the distribution levels 24, 26, 28 (Step 2018). Riser cable 14 slack may be stored in the FDT 29 at the distribution level 24, 26, 28 and/or in the payout reels 18(1), 18(2),18(3) (Step 2020). The payout reels 18(1), 18(2),18(3) may be removably mounted in the FDT 29. Slack may also be stored in the patch panel enclosure 20.
FIG. 11 is a schematic diagram of a front, perspective view of an exemplary LCP 40 for use with a fiber optic network in a MDU 10. The LCP 40 comprises an enclosure 72 with a door 74 hingedly attached to the enclosure 72. The door 74 closes to restrict and/or prohibit access to the interior 76 of the enclosure 72 and the components mounted therein, and opens to allow access to the interior 76 and the components mounted therein. A swingable adapter panel 78 mounts in the interior 76. The adapter panel 78 has a first side 80 (not visible in FIG. 11) and a second side 82 to provide connections of optical fibers 83 between a feeder side and a distribution side. Pivot points 96 positioned at the top and bottom of the interior 76 allow the adapter panel to swing to provide access to the first side 80 or the second side 82 depending on the positioning of the adapter panel 78. Additionally, the adapter panel is lockable in one or more positions. The adapter panel 78 splits the interior 76 into a first section 84 and a second section 86. The LCP 40 is flexible such that either or both the first section 84 or the second section 86 can be configured to support feeder side optical fiber 83 management and/or connections, and/or distribution side optical fiber 83 management and/or connections.
The adapter panel 78 has a connection field 88 that supports fiber optic adapters and connections, as well as pass-through adapters and connections. In FIG. 11, the feeder cable 42 is shown as entering the LCP 40 at the bottom into the first section 84 and connecting to splice trays 92. A continuing section 42(1) of the feeder cable 42 extends from the bottom of the second side 86 to further provide optical connection from the service provider to other areas of the MDU 10 and/or to other MDU's and/or facilities. The distribution cable 36 extends from the top of the first section 84. The distribution cable 36 optically connects to one or more riser cables 14, which may be through a multi-fiber adapter assembly 34 in a patch panel housing 20. One or more splitters 94 may also be mounted in the LCP 40 to split the optical signal carried by the feeder cable 42 into multiple optical signals for distribution. Fiber routing guides 98 and fiber management guides 100 may also be mounted in the first section 84 and/or the second section 86.
FIGS. 11A, 11B and 11C are schematic diagrams of front, perspective, exploded views of the LCP 40 illustrating interior panels 102(1), 102(2), 102(3) which may be used in the LCP 40. The interior panels 102(1), 102(2), 102(3) are interchangeable and allow the LCP 40 enclosure 72 to be easily reconfigured at the factory or in the field. This allows the enclosure 72 to be configured and reconfigured to support multiple applications and changing subscriber situations. In this manner, the interior panels 102(1), 102(2), 102(3) can support, without limitation, fiber splicing, multiple splitter form factors, cable entries and other various modifications or arrangements of the LCP 40. Additionally, the interior panels 102(1), 102(2), 102(3) can be installed on the either the first section 84 or second section 86 of the interior 76 using any type of fasteners 104, such as, without limitation, screws, latches and the like allowing for removable attachment.
In this regard, FIG. 11A illustrates an interior panel 102(1) removably mountable to the enclosure 72 in the interior 76 in the first section 84 configured to support optical fiber splicing having splice trays 92 and optical fiber management guides 100. FIG. 11B illustrates an interior panel 102(2) removably mountable to the enclosure 72 in the interior 76 in the second section 86 configured to support optical fiber splitting having splitters 94 and optical fiber management guides 100. FIG. 11C illustrates an interior panel 102(2) removably mountable to the enclosure 72 in the interior 76 in the second section 86 configured to support optical fiber splicing having splice trays 92 and optical fiber management guides 100. Similarly, although not shown, an interior panel 102 removably mountable to the enclosure 72 in the interior 76 in the first section 84 may be configured to support optical fiber splitting having splitters 94 and optical fiber management guides 100. Additionally or alternatively, the interior panels 102 may be configured to support any type of function or component, as examples, without limitation, furcation devices, ribbon fan-out bodies, wave division multiplexing, coarse wave division multiplexing and others.
The LCP 40 provides for a smaller form factor while allow a high density of optical fiber connections for distribution of optical service to the MDU 10. Additionally, the LCP 40 allows for various options for feeder and distribution cables and of multiple splitters including, without limitation, at least five 1×32 splitters. The LCP 40 can also function as a demarcation point providing 1×1 input to output connections.
FIG. 12 is a schematic diagram of front, elevation views of an exemplary transition box 20 with a multi-fiber adapter assembly 34 and multiple payout reels 18 removably mounted therein. The transition box 20 has a door 104 hingedly attached thereto. The door 104 closes to restrict and/or prohibit access to the interior 106 of the patch panel enclosure 20 and the components mounted therein, and opens to allow access to the interior 106 and the components mounted therein. In FIG. 12, a multi-fiber adapter assembly 34 and multiple payout reels 18(1), 18(2), 18(3), 18(4), are shown mounted in the interior 106. The riser cables 14(1), 14(2), 14(2), 14(2) are shown as having been paid out from the payout reels 18(1), 18(2), 18(3), 18(4) which are now being used to store riser cable 14(1), 14(2), 14(2), 14(2) slack. The payout reels 18(1), 18(2), 18(3), 18(4) are shown as being collapsible being collapsed to a smaller form factor allowing for storing in the transition box 20. The first multi-fiber connectors 30(1), 30(2), 30(3), 30(4) route and connect to one side of the with the multi-fiber adapter assembly 34. The distribution cable 36 connects to the other end of the multi-fiber adapter assembly 34 and extends from the bottom of the transition box 20. Mounting holes 108 allow the transition box 20 to be wall mounted, rack mounted, or any type of mounting.
FIG. 13 is a schematic diagram of a front, perspective view of a FDT 129 having a payout reel 18 and an adapter module assembly 110 with an adapter module 112 and a multi-fiber adapter assembly 34 removably mounted therein. In the embodiment depicted in FIG. 13, the FDT 129 is configured to be mounted in-line with and supported by conduit 113 carrying the riser cable 14 and may be mounted at one or more distribution levels 24, 26, 28. The FDT 129 has an enclosure 114 with a door 116 hingedly attached thereto. The door 116 closes to restrict and/or prohibit access to the interior 118 of the FDT 129 and the components mounted therein, and opens to allow access to the interior 118 and the components mounted therein. In FIG. 13, the adapter module assembly 110 is shown mounted to the door 116 in the interior 118. The adapter module assembly 110 comprises a connector panel 120 to which the adapter module 112 and the multi-fiber adapter assembly 34 attach. The multi-fiber adapter assembly 34 has multi-fiber adapters 120. Additionally, the adapter module 112 has a multi-fiber adapter 122 and multiple single fiber adapters 124. In this manner, the adapter module assembly 110 can receive and connect the riser cable 14 to drop cables 44 extending to subscriber premises 48 located on the distribution levels 24, 26, 28.
Routing guides 126 to route and manage fiber optic cables mount to the door 116 in the interior 118 in addition to the adapter module assembly 110. The door 116 has a flange 128 having a tool lock mechanism 130 and a pad lock hole 132. A flange 134 on the enclosure 114 has a tool lock receiver 136 and pad lock hole 138, which mate with the tool lock mechanism 130 and a pad lock hole 132 when the door 116 is closed to provide for locking the FDT 129. The riser cable 14 is shown as having been paid out from the payout reel 18 which is now being used to store riser cable 14 slack. The payout reel 18 is shown as being collapsible being collapsed to a smaller form factor allowing for storing in the FDT 129.
FIG. 14 is a schematic diagram of a front, perspective view of an exemplary FDT 229 having a payout reel 18 removably mounted therein and an adapter module assembly 210 pivotably mounted therein. The FDT 229 has an enclosure 214 with a door 216 hingedly attached thereto, and may be located at one or more distribution levels 24, 26, 28. The door 216 closes to restrict and/or prohibit access to the interior 218 of the FDT 229 and the components mounted therein, and opens to allow access to the interior 218 and the components mounted therein. The adapter module assembly 210 has a cradle 136 adapted to removably hold one or more adapter modules 112. The cradle 136 has a slack storage area 138 for storing the slack of drop cables 44 extending to subscriber premises 48 located at the distribution level 24, 26, 28. A routing guide 240 connecting to and extending from the cradle provides for drop cable 44 routing and management in the FDT 229. One or more mounting ears 142 extend from the enclosure 214 allowing the enclosure 214 to be mounted to a wall, for example in a closet, at the distribution level 24, 26, 28. The door 216 has a flange 228 having a tool lock mechanism 130 and a pad lock hole 132. A flange 234 on the enclosure 214 has a tool lock receiver 136 and pad lock hole 138, which mate with the tool lock mechanism 130 and a pad lock hole 132 when the door 116 is closed to provide for locking the FDT 229. The riser cable 14 is shown as having been paid out from the payout reel 18 which is now being used to store riser cable 14 slack. The payout reel 18 is shown as being collapsible being collapsed to a smaller form factor allowing for storing in the FDT 229.
FIG. 15 is a schematic diagram of the front, perspective view of the FDT 229 with the adapter module assembly 210 pivoted to an open position. The adapter module assembly 210 has a pivot assembly 144 connected to the bottom of the enclosure 214. In FIG. 15, the pivot assembly 144 is illustrated as a cradle bracket 146 and a cradle hinge 148. However, the pivot assembly 144 can be any mechanical or structural design that allows the adapter module assembly 210 to pivot. Sealing feature 150 allows the riser cable 14 and drop cables 44 to enter the enclosure 214 while maintaining the FDT 229 in an environmentally sealed condition. One or more strain relief brackets 152 provide strain relief for the riser cable 14 and drop cables 44 in the FDT 229.
FIGS. 16 and 17 illustrate a transition box 230 with a chamber wall 232 that divides the interior of the transition box into a dry chamber 234 and a wet chamber 236. Fiber optic cable, such as riser cable 14, may enters the transition box 230 in the wet chamber 236. The riser cable 14 may be front loaded into slot 238. A slotted foam seal 240 may be provided in the slot 238. While the seal 240 provides protection against foreign particle entry, it may not provide a water tight seal. The riser cable 14 is forms into a drip loop 240 in the wet chamber such that any water entering the transition box 230 is restricted to the wet chamber 236. The riser cable 14 extends to optical components, for example, connectors 30, adapters assembly 34 and cable reels 18 mounted in the dry chamber 234.
Many modifications and other embodiments set forth herein will come to mind to one skilled in the art to which the embodiments pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the description and claims are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. It is intended that the embodiments cover the modifications and variations of the embodiments provided they come within the scope of the appended claims and their equivalents. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

## Claims

1. A transition box for a fiber optic network for a multiple distribution unit (MDU), comprising:
an enclosure comprising an interior area;
at least one fiber optic adapter removably mounted in the interior area of the enclosure, wherein the at least one fiber optic adapter is configured to receive one or more optical fibers of a riser cable to provide optical communication service from a service provider to a subscriber premises; and
at least one payout reel removably mounted in the interior area of the enclosure, wherein the at least one payout reel stores slack of the riser cable paid out to at least one of one or more distribution levels in the MDU.

2. The transition box of claim 1, wherein the at least one fiber optic adapter is comprised of at least one multi-fiber adapter configured to receive at least one first multi-fiber connector connected to a first end of the riser cable.

3. The transition box of claim 1, wherein the at least one fiber optic adapter is comprised of at least one multi-fiber adapter configured to receive at least one second multi-fiber connector connected to a second end of the riser cable.

4. The transition box of claim 1, wherein the enclosure comprises at least one patch panel enclosure located at a lower level of the MDU.

5. The transition box of claim 4, wherein the at least one fiber optic adapter provides optical connection between one or more optical fibers of the riser cable and one or more optical fibers of a distribution cable, and wherein the distribution cable extends to a local convergence point (LCP), and wherein optical connection between the one or more optical fibers of the distribution cable and one or more optical fibers of a feeder cable is established at the LCP.

6. The transition box of claim 5, wherein the at least one fiber optic adapter provides optical connection between at least one first multi-fiber connector at a first end of the riser cable and at least one multi-fiber connector at an end of the distribution cable.

7. The transition box of claim 1, wherein the enclosure comprises a fiber distribution terminal (FDT) located at one of the one or more distribution levels.

8. The transition box of claim 7, wherein the FDT is a pipe-in-box mounted on and supported by a conduit carrying the riser cable.

9. The transition box of claim 7, wherein the FDT is a closet box separately mountable on a surface at the distribution level.

10. The transition box of claim 7, wherein the at least one fiber optic adapter provides optical connection between one or more optical fibers of the riser cable and one or more optical fibers of a drop cable, and wherein the drop cable extends to a subscriber premises.

11. The transition box of claim 10, wherein the at least one fiber optic adapter provides optical connection between at least one second multi-fiber connector at a second end of the riser cable and at least one multi-fiber connector at an end of the drop cable.

12. The transition box of claim 10, wherein the at least one fiber optic adapter provides optical connection between at least one second multi-fiber connector at a second end of the riser cable and at least one multi-fiber connector at an end of a cable harness.

13. The transition box of claim 12, wherein the cable harness extends and connects to one or more single fiber adapters.

14. The transition box of claim 13, wherein at least one of the one or more single fiber adapters provides an optical connection between an optical fiber of the cable harness and an optical fiber of a drop cable.

15. The transition box of claim 14, wherein the drop cable extends to a subscriber premises.

16. A transition box for a fiber optic network for a multiple distribution unit (MDU), comprising:
an enclosure comprising an interior area;
a module removably mounted in the interior area of the enclosure;
at least one fiber optic adapter assembly pivotably mounted in the module, wherein the at least one fiber optic adapter assembly comprises at least one multi-fiber adapter and at least one single fiber adapter, and wherein a riser cable optically connects at the fiber optic adapter assembly to provide optical communication service to a subscriber premises; and
at least one payout reel removably mounted in the interior area of the enclosure, wherein the at least one payout reel stores slack of the riser cable paid out to extend to at least one of one or more distribution levels in the MDU.

17. The transition box of claim 16, wherein the at least one multi-fiber adapter at a first end receives at least one multi-fiber connector connected to an end of the riser cable and at a second end receives at least one multi-fiber connector connected to an end of a drop cable.

18. The transition box of claim 17, wherein the drop cable is a multi-fiber bundled drop cable.

19. The transition box of claim 18, wherein the drop cable is a multi-fiber bundled drop cable.

20. The transition box of claim 19, wherein the drop cable extends to a drop box located at a subscriber premises.

21. The transition box of claim 20, wherein at least one optical fiber of the drop cable separates from the drop cable and extends to the subscriber premises.

22. The transition box of claim 16, wherein the at least one multi-fiber adapter at a first end receives at least one multi-fiber connector connected to an end of the riser cable and at a second end receives at least one multi-fiber connector connected to a cable harness.

23. The transition box of claim 22, wherein the optical fibers of the cable harness furcate, and wherein an end of at least one of the optical fibers has at least one single fiber connector.

24. The transition box of claim 23, wherein one of the at least one single fiber adapter at a first end receives the at least one single fiber connector of the optical fiber of the cable harness, and at a second end receives at least one single fiber connector at the end of a drop cable.

25. The transition box of claim 24, wherein the drop cable extends to a subscriber premises.

26. The transition box of claim 1, wherein the at least one payout reel is configured to be collapsed from a first form factor to a second form factor smaller than the first form factor in the interior area of the enclosure.

27. The transition box of claim 16, further comprising a cradle disposed in the interior area of the enclosure, the cradle removably holding the module in the interior area of the enclosure to mount the module in the interior area of the enclosure.

28. The transition box of claim 27, wherein the at least one payout reel is configured to be collapsed from a first form factor to a second form factor smaller than the first form factor in the interior area of the enclosure.