WO2019143510A1

WO2019143510A1 - Fiber-to-the-home architecture

Info

Publication number: WO2019143510A1
Application number: PCT/US2019/012903
Authority: WO
Inventors: Motaz Mohd ABULIBEH; Mahmoud B. ELMADHOUN; David B. Hughes
Original assignee: Commscope Technologies LLC
Current assignee: Commscope Technologies LLC
Priority date: 2018-01-16
Filing date: 2019-01-09
Publication date: 2019-07-25
Anticipated expiration: 2020-07-16
Also published as: SA520412440B1

Abstract

Aspects of the present disclosure relate to fiber optic devices, systems, networks, and methods that allow for a fiber optic distribution network to be expanded over time. The fiber optic devices include a terminal having a terminal housing and a demateable fiber optic connector port accessible from outside the terminal housing. Each fiber optic device includes an exterior mechanical interface configured to couple an add-on splitter module to the terminal housing.

Description

FIBER-TO-THE-HOME ARCHITECTURE

Cross-Reference to Related Application

[0001] This application is being filed on January 9, 2019 as a PCT International Patent Application and claims the benefit of U.S. Patent Application Serial No. 62/617,859, filed on January 16, 2018, the disclosure of which is incorporated herein by reference in its entirety.

Technical Field

[0002] The present disclosure relates generally to fiber optic devices, systems, networks, and methods. More specifically, the present disclosure relates to add-on fiber optic devices or modules that can be selectively, individually added onto primary fiber optic devices to expand the capacity of the primary fiber optic devices.

Background

[0003] Fiber optic communication systems are becoming prevalent in part because service providers want to deliver high bandwidth communication capabilities (e.g., data invoice) to customers. Fiber optic communication systems employ a network of fiber optic cables to transmit large volumes of data and voice signals over relatively long distances. Fiber optic connectors and fiber optic enclosures are an important part of most fiber optic communication systems.

[0004] A common fiber-to-the-home (FTTH) architecture includes a network of fiber optic distribution cables routed from a central office (e.g., a service provider location) to a plurality of enclosures such as fiber distribution hubs (FDH). A typical fiber distribution hub includes one or more passive optical power splitters. The network architecture also includes a plurality of multi-fiber optical cables that radiate outwardly from the fiber distribution hubs toward the edge of the fiber optic network. It will be appreciated that the edge of the fiber optic network is typically the portion of the fiber optic network closest to the subscriber locations.

[0005] Multi-service terminals (e.g., drop terminals) are optically connected to the fiber optic cables radiating outwardly from the fiber distribution hubs at locations along the fiber optic cables generally in the vicinity of subscriber locations. The multi-service terminals each include a plurality of hardened fiber optic adapter ports that are accessible from outside the multi-service terminals. Example multi-service terminals having multiple hardened adapter ports are disclosed by U.S. Patent No. 8,363,999.

[0006] For a typical architecture, it is desirable for the multi-service terminals to have significantly more hardened fiber optic adapter ports than are intended to be coupled to subscribers during initial deployment. By providing an excess number of hardened adapter ports, excess capacity is provided to allow for future expansion. Flowever, such initially unused hardened adapter ports can significantly increase cost of the initial deployment. Additionally, with this type of architecture, once all of the excess hardened adapter ports have been utilized, further expansion is difficult.

Summary

[0007] Aspects of the present disclosure relate to fiber optic devices, systems, networks, and methods adapted to reduce the complexity in deploying a fiber optic network. Other aspects relate to fiber optic devices, systems, networks, and methods that enhance the speed of deployment of a fiber optic network and also enhance optical line terminal (OLT) utilization. Still other aspects of the present disclosure relate to fiber optic devices, systems, networks, and methods adapted to reduce the initial investment costs associated with deploying a fiber optic network while also allowing for the effective and efficient expansion of the network to meet subscriber demand. A further aspect of the present disclosure relates to fiber optic devices, systems, networks, and methods that allow fiber optic networks to be deployed with relatively simple surveys. In certain examples, initial fiber optic networks can have relatively simple designs that can be expanded to accommodate a wide number of subscriber locations.

[0008] In one example of the present disclosure, fiber optic devices each including a primary terminal having a demateable fiber optic connector port accessible from outside a terminal housing are integrated throughout a fiber optic network. In certain examples, the primary terminals are arranged in a satellite-type network architecture.

[0009] In one example, primary fiber optic devices having primary terminals each including only one demateable fiber optic connector port are expandable in capacity from only one port to two, four, eight, sixteen, thirty-two, sixty -four, or more ports. In certain examples, the fiber optic devices include primary terminals and add-on modules that are highly modular and that are connectable by plug-and play connections. In certain examples, the primary terminals and add-on terminals have sealed and hardened configurations adapted for outdoor environmental use. In certain examples, the primary terminals include hardened demateable fiber optic connection locations that have plug-and play configurations, that are environmentally sealed, and that can be accessed from outside the terminal housing without accessing an interior of the terminal housing. In certain examples, the primary terminals in accordance with the principles of the present disclosure include relatively robust connector fastening interfaces such as threaded interfaces, bayonet-style interfaces, or other robust mechanical interfaces for allowing hardened fiber optic connectors to be secured to the terminals.

[0010] One aspect of the present disclosure relates to a fiber optic device comprising: a terminal including a terminal housing and a demateable fiber optic connector port accessible from outside the terminal housing, the terminal housing also including an exterior mechanical interface configured to couple to an add-on splitter module; and a fiber optic tether cable having a first end coupled to the terminal housing and a second end being remote from the terminal housing, the fiber optic tether cable having an optical fiber configured for optical coupling at the demateable fiber optic connector port of the terminal housing from outside the terminal housing. In one example, the optical fiber includes a connectorized first end within the terminal housing, the connectorized first end is supported by a non-ruggedized connector, the demateable fiber optic connector port includes a fiber optic adapter including an inner connector port accessible from inside the terminal housing for receiving the non-ruggedized connector, and the fiber optic adapter also includes an outer connector port accessible from outside the terminal housing, the outer connector port being configured for receiving a hardened fiber optic connector. In one example, the outer connector port includes a twist-to-lock interface to connect with the hardened fiber optic connector. In another example, the fiber optic device further comprises a dust plug to environmentally seal the outer connector port when not receiving the hardened fiber optic connector, the fiber optic adapter is environmentally sealed relative to the terminal housing, and an environmental seal is provided between the fiber optic adapter and the hardened fiber optic connector when the hardened fiber optic connector is secured within the outer connector port. In a further example, the fiber optic tether cable includes an outer jacket surrounding the optical fiber and a reinforcing strength layer including aramid yarn positioned between the optical fiber and the jacket. In one example, the second end of the fiber optic tether cable is either connectorized or splice-ready.

[0011] Another aspect of the present disclosure relates to a fiber optic device including a terminal having a terminal housing with a single demateable fiber optic connector port accessible from outside the terminal housing. The terminal housing also includes an exterior mechanical interface for mechanically coupling an add-on splitter module to the terminal housing. The fiber optic device further includes a fiber optic tether cable having a first end coupled to the terminal housing and a second end that can be positioned remote from the terminal housing. The fiber optic tether cable includes a single optical fiber available for optical connection (e.g., to a hardened fiber optic connector) at the single demateable fiber optic connector port of the terminal housing from outside the terminal housing. In certain examples, the demateable fiber optic connection interface can be provided by a male fiber optic connector (e.g., a hardened male fiber optic connector) or a female fiber optic connector (e.g., a hardened female fiber optic connector) such as a fiber optic adapter defining a port for receiving a hardened male fiber optic connector. In one example, the single demateable fiber optic connector port is provided by a hardened fiber optic adapter that is mounted in a sealed relation relative to the terminal housing. An example hardened fiber optic adapter is disclosed by U.S. Patent No. 7,952,590, which is hereby incorporated by reference in its entirety. In certain examples, both the terminal housing and the add-on splitter module are adapted for outside use and are

environmentally sealed. In certain examples, the fiber optic tether cable of the fiber optic device is relatively long and can have a length of at least 10 meters, or at least 25 meters, or at least 50 meters, or at least 75 meters, or at least 100 meters, or at least 250 meters, or at least 500 meters. In certain examples, the second end of the fiber optic tether cable can be connectorized with either a hardened or non-hardened fiber optic connector or alternatively can be splice-ready.

[0012] A further aspect of the present disclosure relates to a fiber optic system comprising: a primary fiber optic device including: a primary terminal including a primary terminal housing and a primary fiber optic adapter including an inner connector port accessible from inside the primary terminal housing and an outer connector port accessible from outside the primary terminal housing, the primary terminal also including a primary exterior mechanical interface; and a primary fiber optic tether cable having a first end coupled to the primary terminal housing and a second end being remote from the primary terminal housing, the primary fiber optic tether cable having a primary tether optical fiber including a connectorized first end received within the inner connector port of the primary fiber optic adapter; and a secondary fiber optic device including: a secondary terminal including a secondary terminal housing containing an optical power splitter, the secondary terminal including a secondary exterior mechanical interface configured to couple to the primary exterior mechanical interface to mount the secondary terminal housing to the primary terminal housing, the secondary terminal including a plurality of secondary fiber optic adapters having inner connector ports accessible from inside the secondary terminal housing and outer connector ports accessible from outside the secondary terminal housing, the secondary terminal including splitter output optical fibers having first ends optically coupled to an output of the optical power splitter and second ends positioned at the inner connector ports, the second ends of the splitter output optical fibers being connectorized; and a secondary fiber optic tether cable having a first end coupled to the secondary terminal housing and an opposite second end terminated by a hardened fiber optic connector configured to mate with the outer connector port of the primary fiber optic adapter, the secondary fiber optic tether cable also including a secondary tether optical fiber having a first end optically coupled to an input of the optical power splitter and a second end terminated by the hardened fiber optic connector; and the primary tether optical fiber is optically coupled to the secondary tether optical fiber and an output of the optical power splitter when the hardened fiber optic connector is secured within the outer connector port of the primary fiber optic adapter. In one example, the fiber optic system further comprises a plurality of secondary fiber optic devices each having a different optical split ratio.

[0013] Another aspect of the present disclosure relates to a fiber optic system including a primary fiber optic device and a secondary fiber optic device. The primary fiber optic device includes a primary terminal including a primary terminal housing and a primary fiber optic adapter including a first connector port accessible from inside the primary terminal housing and a second connector port accessible from outside the primary terminal housing. The primary terminal also includes an exterior first mechanical interface. The primary fiber optic device further includes a primary fiber optic tether cable having a first end coupled to the primary terminal housing and a second end that can be positioned remote from the terminal housing. The primary fiber optic tether cable has a single primary tether optical fiber including a connectorized end received within the first connector port of the primary fiber optic adapter. The secondary fiber optic device includes a secondary terminal including a secondary terminal housing containing a passive optical power splitter. The secondary terminal includes a second mechanical interface adapted to couple to the first mechanical interface of the primary terminal to mount the secondary terminal housing to the primary terminal housing. The secondary terminal includes a plurality of secondary fiber optic adapters having first connector ports accessible from inside the secondary terminal housing and second connector ports accessible from outside the secondary terminal housing. In certain examples, the second connector ports of the secondary fiber optic adapters are hardened. The second terminal housing includes splitter output fibers having first ends coupled to outputs of the passive optical power splitter and second ends positioned at the first connector ports. The second ends of the splitter output optical fibers are connectorized. The secondary fiber optic device also includes a secondary fiber optic tether cable having a first end coupled to the secondary terminal housing and an opposite second end terminated by a hardened fiber optic connector configured to mate with the second connector port of the primary fiber optic adapter. The secondary fiber optic tether cable includes a secondary tether optical fiber having a first end optically coupled to an input of the passive optical power splitter and a second end supported by the hardened fiber optic connector. By inserting the hardened fiber optic connector terminating the second end of the secondary fiber optic tether cable into the second connector port of the primary fiber optic adapter, the single primary tether optical fiber is optically connected to the secondary tether optical fiber and thus is also optically coupled to the input of the passive optical power splitter.

[0014] A further aspect of the present disclosure relates to a fiber optic network comprising: a fiber distribution hub optically coupled to a service provider location by a primary multi-fiber distribution cable, the fiber distribution hub including one or more optical power splitters each having a different optical splitter output; a secondary multi- fiber distribution cable routed outwardly from the fiber distribution hub, the secondary multi-fiber distribution cable including optical fibers optically coupled to the one or more optical power splitters; and primary fiber optic devices each including a terminal having a demateable fiber optic connector port accessible from outside the terminal and each including an exterior mechanical interface configured to mechanically couple an add-on splitter module to the terminal of the primary fiber optic device, each primary fiber optic device also including a primary fiber optic tether cable extending outwardly from the terminal, the primary fiber optic tether cables each being optically coupled to one of the optical fibers of the secondary multi-fiber distribution cable. In one example, the primary fiber optic tether cables are optically coupled to the optical fibers of the secondary multi fiber distribution cable at a closure through which the secondary multi-fiber distribution cable passes through. In another example, the fiber optic network further comprises drop cables that extend between the demateable fiber optic connector ports and subscriber locations. In a further example, the primary fiber optic devices include first and second primary fiber optic devices, the first primary fiber optic device being optically coupled to a first subscriber location by a drop cable having a hardened fiber optic connector plugged into the demateable fiber optic connector port of the first primary fiber optic device; and the fiber optic network further comprising an add-on splitter module, the add-on splitter module including an optical power splitter having an output coupled to a plurality of splitter output ports, the add-on splitter module also including a secondary terminal containing the optical power splitter and being mechanically coupled to the terminal of the second primary fiber optic device at the exterior mechanical interface; wherein an input of the optical power splitter being optically coupled to the second primary fiber optic device by a secondary fiber optic tether cable having a hardened fiber optic connector plugged into the demateable fiber optic connector port of the second primary fiber optic device; and wherein a drop cable provides an optical connection between one of the splitter output ports of the add-on splitter module and a second subscriber location. In another example, the fiber optic network further comprises a plurality of add-on splitter modules at the fiber distribution hub, the plurality of add-on splitter modules including first and second optical power splitters, the first optical power splitter has a higher split ratio than the second optical power splitter, wherein a first primary fiber optic device is optically coupled to a splitter output of the first optical power splitter, and a second primary fiber optic device is optically connected to a splitter output of the second optical power splitter.

[0015] Another aspect of the present disclosure relates to a fiber optic network configuration including a fiber distribution hub optically connected to a service provider location by a first fiber optic distribution cable. The fiber distribution hub includes one or more optical power splitters each having a different optical splitter outputs. A multi-fiber optical distribution cable is routed outwardly from the fiber distribution hub. The multi- fiber optical distribution cable includes optical fibers optically coupled to the splitter outputs of the one or more optical power splitters. The fiber optic network configuration also includes a plurality of primary fiber optic devices each including a primary terminal defining a single hardened connector port accessible from outside the primary terminal. The primary terminals also include exterior mechanical interfaces for mechanically coupling add-on splitter modules to the primary terminals. The primary fiber optic devices also include primary fiber optic tethers that extend outwardly from the primary terminals. The primary fiber optic tethers each are optically connected to one of the optical fibers of the multi-fiber distribution cable and each primary fiber optic tether includes a single optical fiber.

[0016] A further aspect of the present disclosure relates to a method for expanding a fiber optic network, the fiber optic network including a fiber distribution hub including a first optical power splitter, the fiber optic network also including a primary terminal that is remotely positioned with respect to the fiber distribution hub, the primary terminal having a demateable fiber optic connector port accessible from outside the terminal, the demateable fiber optic connector port being coupled to an output of the first optical power splitter, the fiber optic network also including a first drop cable routed from the demateable fiber optic connector port of the primary terminal to a first subscriber location, the method comprising: disconnecting the first drop cable from the demateable fiber optic connector port of the primary terminal; mechanically attaching an add-on splitter module to the primary terminal, the add-on splitter module including a secondary terminal housing containing a second optical power splitter, the second optical power splitter including additional splitter output ports coupled to an output of the first optical power splitter; coupling an input of the second optical power splitter to the demateable fiber optic connector port of the primary terminal; routing the first drop cable from a first splitter output port of the add-on splitter module to the first subscriber location; routing a second drop cable from a second splitter output port of the add-on splitter module to a second subscriber location; and disconnecting the demateable fiber optic connector port of the primary terminal from the output of the first optical power splitter, and subsequently coupling the demateable fiber optic connector port of the primary terminal to an output of a third optical power splitter at the fiber distribution hub, the third optical power splitter having a lower split ratio than the first optical power splitter. In one example, the step of uncoupling the demateable fiber optic connector port from the output of the first optical power splitter is remotely controlled by a switching matrix to transfer the demateable fiber optic connector port to the output of the third optical power splitter at the fiber distribution hub.

[0017] Another aspect of the present disclosure relates to a method for expanding a fiber optic network. The fiber optic network includes a fiber distribution hub including a first optical power splitter. The fiber optic network also includes a primary terminal that is remotely positioned with respect to the fiber distribution hub. The primary terminal has a single hardened connector port accessible from outside the primary terminal. The single hardened connector port is coupled to an output of the first optical power splitter. The fiber optic network also includes a first drop cable routed from the hardened connector port of the primary terminal to a first subscriber location. The method includes disconnecting the first drop cable from the hardened connector port of the primary terminal. The method also includes mechanically attaching an add-on splitter terminal to the primary terminal. The add-on splitter terminal includes a module housing containing a second passive optical power splitter. The add-on splitter terminal also includes hardened output splitter ports coupled to outputs of the second passive optical power splitter. The method includes coupling an input of the second passive optical power splitter to the hardened connector port of the primary terminal. The method also includes connecting the first drop cable to a first one of the hardened connector ports of the add-on splitter module. The method further includes routing a second drop cable from a second one of the hardened connector ports of the add-on splitter module to a second subscriber location.

The method additionally includes disconnecting the single hardened connector port of the primary terminal from the output of the first passive optical power splitter and

subsequently coupling the single hardened connector port of the primary terminal to an output of a third passive optical power splitter at the fiber distribution hub. The third passive optical power splitter has a lower split ratio than the first passible optical power splitter.

[0018] A variety of additional aspects will be set forth in the description that follows. The aspects relate to individual features and to combinations of features. It is to be understood that both the forgoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the examples disclosed herein are based. Brief Description of the Drawings

[0019] Figure 1 schematically illustrates a fiber optic system.

[0020] Figure 2 illustrates a primary fiber optic device of the fiber optic system.

[0021] Figure 3 illustrates another view of the primary fiber optic device.

[0022] Figure 4 illustrates a hardened fiber optic adapter that can be used with primary fiber optic devices and secondary fiber optic devices.

[0023] Figure 5 illustrates a cross-sectional view taken lengthwise through the hardened fiber optic adapter of Figure 4.

[0024] Figure 6 illustrates an exploded view showing the hardened fiber optic adapter of Figure 4 coaxially aligned with and positioned between a non-ruggedized fiber optic connector and a hardened fiber optic connector.

[0025] Figure 7 illustrates the hardened fiber optic adapter and the hardened fiber optic connector of Figure 6.

[0026] Figure 8 illustrates a secondary fiber optic device of the fiber optic system.

[0027] Figure 9 is another view of the secondary fiber optic device of Figure 8.

[0028] Figure 10 schematically illustrates an initially deployed fiber optic network in accordance with the principles of the present disclosure.

[0029] Figure 11 schematically illustrates another view of the initially deployed fiber optic network of Figure 10.

[0030] Figure 12 schematically illustrates a later deployed fiber optic network in accordance with the principles of the present disclosure.

[0031] Figure 13 schematically illustrates another view of the later deployed fiber optic network of Figure 12.

[0032] Figure 14 is a cross-sectional view of a fiber optic tether cable taken through section line 14-14 of Figure 1. Detailed Description

[0033] Figure 1 illustrates a fiber optic system 20 in accordance with the principles of the present disclosure. The fiber optic system 20 includes a primary fiber optic device 22 and a plurality of secondary fiber optic devices 24a-24e. The secondary fiber optic devices 24a-24e are preferably add-on fiber optic devices or splitter modules that can be selectively, individually added onto the primary fiber optic device 22 to expand the capacity of the primary fiber optic device 22.

[0034] The primary fiber optic device 22 includes a primary terminal 26 including a primary terminal housing 28. The primary terminal 26 includes a single demateable fiber optic connector port 30 accessible from outside the primary terminal housing 28. The primary terminal housing 28 includes a primary exterior mechanical interface 32 that can be used to mechanically couple a selected one of the secondary fiber optic devices 24a-24e to the primary terminal housing 28.

[0035] The secondary fiber optic devices 24a-24e each include a secondary exterior mechanical interface 34 adapted to interlock, fasten, attach, or otherwise engage with the primary exterior mechanical interface 32.

[0036] Still referring to Figure 1, the primary fiber optic device 22 further includes a primary fiber optic tether cable 36 having a first end 38 coupled to the primary terminal housing 28 and a second end 40 that can be positioned remote from the primary terminal housing 28. In one example, the primary fiber optic tether cable 36 has an optical fiber 42 (see Figures 2, 3, and 14) available for optical connection to a fiber optic connector (e.g., a hardened fiber optic connector) at the single demateable fiber optic connector port 30 from outside the primary terminal housing 28.

[0037] The secondary fiber optic devices 24a-24e can be used to expand the capacity of the primary fiber optic device 22. For example, when the primary fiber optic device 22 is initially deployed, the single demateable fiber optic connector port 30 provides an optical connection location where a drop cable can be connected for connecting the primary fiber optic device 22 to a subscriber location. Over time, additional connector ports may be needed. By adding one of the secondary fiber optic devices 24a-24e to the primary fiber optic device 22, the port count of the primary fiber optic device 22 can be increased. [0038] The port count may be gradually increased by coupling the secondary fiber optic devices 24a-24e with progressively higher port counts to the primary fiber optic device 22 over time. For example, a secondary fiber optic device 24a-24e with a lower port count can be replaced with a secondary fiber optic device 24a-24e with a higher port count over time. Typically, only one of the secondary fiber optic devices 24a-24e would be mounted to the primary fiber optic device 22 at a given moment in time.

[0039] Referring still to Figure 1, the secondary fiber optic devices 24a-24e are depicted as add-on splitter modules each containing a passive optical power splitter 54.

The secondary fiber optic devices 24a-24e each include a secondary terminal 50 including a secondary terminal housing 52 containing a passive optical power splitter 54. Each of the secondary terminal housings 52 includes a secondary exterior mechanical interface 34 that is adapted to couple with the primary exterior mechanical interface 32 of the primary terminal 26. Each of the secondary terminals 50 includes a plurality of splitter output ports 56 with the port count of each of the primary terminals being equal to the split ratio of the passive optical power splitter 54 provided therein.

[0040] Each secondary fiber optic devices includes a secondary fiber optic tether cable 58 having a first end 60 coupled to the secondary terminal housing 52 and an opposite second end 62 terminated by a hardened fiber optic connector 64 configured to mate with the demateable fiber optic connector port 30 of the primary terminal 26.

[0041] To install one of the secondary fiber optic devices 24a-24e on the primary terminal 26, the secondary exterior mechanical interface 34 of the selected secondary fiber optic device 24a-24e is coupled to the primary exterior mechanical interface 32 of the primary terminal 26, and the hardened fiber optic connector 64 of the secondary fiber optic tether cable 58 corresponding to the selected secondary fiber optic device 24a-24e is plugged into the demateable fiber optic connector port 30 of the primary fiber optic device 22. In this way, the port count provided at the primary fiber optic device 22 can be increased over time as needed due to growing subscriber demands.

[0042] In certain examples, secondary fiber optic devices 24a-24e each contain a passive optical power splitter 54 having a different split ratio. For example, secondary fiber optic device 24a includes a 1x2 passive optical power splitter and includes 2 splitter output ports 56, the secondary fiber optic device 24b includes a 1x4 passive optical power splitter and includes 4 splitter output ports 56, the secondary fiber optic device 24c includes a 1x8 passive optical power splitter and includes 8 splitter output ports 56, the secondary fiber optic device 24d includes a 1x16 passive optical power splitter and includes 16 splitter output ports 56, the secondary fiber optic device 24e includes a 1x32 passive optical power splitter and includes 32 splitter output ports 56. Additional secondary fiber optic devices with other split ratios and port counts can also be used.

Also, rather than providing a passive optical power splitter within the given secondary fiber optic device, an alternative type of splitting device such as a wavelength division multiplexer can be used to split optical signals based on wavelength. In this regard, the term optical splitter includes both passive optical power splitters as well as wavelength splitters such as wavelength division multiplexers.

[0043] The primary and secondary exterior mechanical interfaces 32, 34 are preferably mechanical interfaces that allow the secondary terminals 50 to be individually attached to the primary terminal 26. In certain examples, the primary and secondary exterior mechanical interfaces 32, 34 include snap-fit connections, slide interlocks, mating mechanical interfaces, or other attachment techniques. In further examples, the primary and secondary exterior mechanical interfaces 32,34 include fasteners such as clips, bolts, latches, screws, or other fasteners. As depicted, each secondary exterior mechanical interface 34 includes a male part 66 that fits within a female part 68 of the primary terminal 26. Also, the primary exterior mechanical interface 32 can include a fastener opening 70 such as an internally threaded blind opening for receiving a fastener such as a bolt that extends through a corresponding fastener opening 72 in the secondary exterior mechanical interface 34.

[0044] The primary terminal 26 can include structure for mounting the primary terminal 26 in the field. For example, it may be desirable to mount the primary terminal 26 to a wall, to a pole, in a hand hole, or to other locations in the field. As depicted at Figure 2, the primary terminal 26 can include tabs 74 defining fastener openings 76 for receiving fasteners that can be used to secure the primary terminal 26 to another structure. In further examples, the primary terminal 26 can include brackets, flanges, other fastener openings, or other arrangements for allowing ready securement of the primary terminal 26 to another structure in the field. [0045] In certain applications, the primary terminal 26 is installed at a location remote from a multi-fiber distribution cable. For example, the primary terminal 26 can be installed at the edge of a fiber optic network near or at a subscriber location. Thus, the primary fiber optic tether cable 36 can have a predetermined length. For example, the primary fiber optic tether cable 36 can be at least 10 meters long, or at least 25 meters long, or at least 50 meters long, or at least 100 meters longs, or at least 250 meters long, or at least 500 meters long. Additional predetermined lengths for the primary fiber optic tether cable 36 are possible.

[0046] In certain examples, the fiber optic tether cables 36, 58 are reinforced with a reinforcing strength layer to provide tensile and/or compressive reinforcement to the tethers. In certain examples, the reinforcing strength layer includes reinforcing yarns such as Aramid yarn or reinforcing rods such as fiberglass reinforced epoxy rods. In certain examples, the first ends 38, 60 of the respective fiber optic tether cables 36, 58 are secured to the terminal housings 28, 52 by attaching the strength members to the respective housings. For example, the strength members can be attached by crimps or fasteners or clamps or other means. The fiber optic tether cables 36, 58 can include outer jackets for surrounding the optical fibers and the reinforcing strength layer.

[0047] Figure 14 shows an example configuration for a primary fiber optic tether cable 36 in which a reinforcing strength layer 80 such as a layer of Aramid yarn is provided between an optical fiber 42 and an outer jacket 82 of the primary fiber optic tether cable 36. The primary terminals 26 include sealing for sealing the locations where the fiber optic tether cables 36, 58 enter the terminals. The sealing can include gel seals, compression seals, heat-shrink seals, gasket-type seals or other sealing techniques.

[0048] The primary terminal housing 28 and the secondary terminal housings 52 include demateable fiber optic connector ports that are accessible from outside the housings. In preferred examples, the demateable fiber optic connector ports are defined by hardened fiber optic adapters. A hardened fiber optic adapter can be described as a hardened female connector having a port accessible from outside the terminal which is adapted to receive a hardened male connector. In other examples, male connectors may alternatively be used at the terminal housings. For example, male or female connectors could be mounted on tethers that extend from the housings. [0049] Referring now to Figure 3, the primary fiber optic device 22 is shown with the demateable fiber optic connector port 30 defined by a hardened fiber optic adapter 90. As shown at Figures 4-6, the fiber optic adapter 90 includes a hardened outer connector port 92 that is accessible from outside the primary terminal housing 28 and a non-hardened inner connector port 94 that is accessible from inside the primary terminal housing 28.

The fiber optic adapter 90 includes an adapter body 96 which may be one or more pieces. The adapter body 96 at least partially defines the hardened outer connector port 92 and the non-hardened inner connector port 94. A ferrule alignment sleeve 98 is mounted within the adapter body 96 in coaxial alignment with the non-hardened inner connector port 94 and the hardened outer connector port 92.

[0050] As shown at Figure 5, the fiber optic adapter 90 can be mounted within an opening 100 defined through a wall of the primary terminal housing 28. The fiber optic adapter 90 is environmentally sealed relative to the primary terminal housing 28 by a seal 102 that provides environmental sealing between the adapter body 96 and the primary terminal housing 28. A nut 104 is threadable onto a threaded portion of the adapter body 96 to clamp the adapter body 96 in place relative to the primary terminal housing 28 and to compress the seal 102. When the hardened outer connector port 92 is not in use (i.e., when a hardened fiber optic connector is not inserted therein), a dust plug 93 having a seal 95 and threads 97 can be threaded into the hardened outer connector port 92 to keep the hardened outer connector port 92 environmentally sealed.

[0051] As further shown in Figure 3, the optical fiber 42 of the primary fiber optic tether cable 36 includes a single primary tether optical fiber 106 having a connectorized first end 108 received within the non-hardened inner connector port 94 of the fiber optic adapter 90. The connectorized first end 108 includes a non-ruggedized connector 110 such as an LC connector or an SC connector. In one example, the non-ruggedized connector 110 includes a ferrule for supporting an end of the single primary tether optical fiber 106. In alternative examples, ferrule-less connectors may be used. In the example shown in FIG. 3, the non-ruggedized connector 110 includes a ferrule 112 received within the ferrule alignment sleeve 98 of the fiber optic adapter 90.

[0052] The ferrule 112 supports an end of the single primary tether optical fiber 106. The single primary tether optical fiber 106 extends from the connectorized first end 108 to the second end 40 of the primary fiber optic tether cable 36. The second end 40 can be connectorized or splice-ready. As used herein, the term“single optical fiber” means that the optical fiber provides one optical transmission path (e.g., it functions as one wave guide). The single optical fiber may include one continuous uninterrupted segment of optical fiber, or may include multiple segments of optical fiber that are optically spliced together to form the single optical transmission path.

[0053] In certain examples, the hardened outer connector port 92 of the fiber optic adapter 90 includes a twist-to-lock interface suitable for mating with a corresponding twist-to-lock interface provided on a hardened fiber optic connector designed to be inserted within the hardened outer connector port 92. Example twist-to-lock interfaces include threaded interfaces and bayonet-style interfaces.

[0054] As shown at Figure 6, the twist-to-lock interface includes a threaded interface 114 defined within the hardened outer connector port 92 which is adapted to mate with a threaded interface 116 provided on a threaded fastener 118 of a hardened fiber optic connector 120 designed to fit within the hardened outer connector port 92. The hardened fiber optic connector 120 includes a seal 122 (see Figure 7) that provides environmental sealing between the fiber optic adapter 90 and the hardened fiber optic connector 120 when the hardened fiber optic connector 120 is secured within the hardened outer connector port 92.

[0055] The hardened fiber optic connector 120 further includes a plug 124 that fits within the hardened outer connector port 92. A ferrule 126 is positioned at an end of the plug 124. The ferrule 126 can support an optical fiber 128 of an optical cable 130 secured to the hardened fiber optic connector 120. When the hardened fiber optic connector 120 is installed within the hardened outer connector port 92, the ferrule 126 fits within the ferrule alignment sleeve 98 such that the optical fiber 128 is co-axially aligned with the single primary tether optical fiber 106 supported by the ferrule 112 of the non-ruggedized connector 110 at the connectorized first end 108 of the single primary tether optical fiber 106. In this way, an optical connection is made between the optical fiber 128 and the single primary tether optical fiber 106.

[0056] Referring to Figures 8 and 9, the secondary fiber optic device 24b is depicted in more detail. It will be appreciated that the secondary fiber optic device 24b is

representative of the secondary fiber optic devices 24a-24e such that all of the secondary fiber optic devices have the same basic configuration, but for the split ratio of the optical power splitter 54 and the number of splitter output ports 56 provided.

[0057] Referring to Figures 8 and 9, the secondary terminal housing 52b is provided with four demateable fiber optic connector ports which are depicted as splitter output ports 56. It will be appreciated that the splitter output ports 56 can be defined by fiber optic adapters 90 of the type described above which are mounted to the secondary terminal housing 52b. For example, each splitter output port 56 includes a fiber optic adapter 90 having a hardened outer connector port 92 which is adapted to receive hardened fiber optic connectors such as the hardened fiber optic connector 120. As used herein, a connector port is a port adapted to receive a fiber optic connector.

[0058] Referring to Figure 9, the secondary fiber optic device 24b includes secondary terminal housing 52 containing a passive optical power splitter 54. The secondary terminal housing 52 further includes a plurality of fiber optic adapters 90 each having a non-hardened inner connector port 94 accessible from inside the secondary terminal housing 52 and a hardened outer connector port 92 accessible from outside the secondary terminal housing 52.

[0059] The secondary terminal housing 52 further includes splitter output optical fibers 140 each having a first end 142 optically coupled to an output of the passive optical power splitter 54 and each having a second end 144 at the non-hardened inner connector ports 94. The second ends 144 of the splitter output optical fibers 140 are connectorized by non-ruggedized connectors 146. The non-ruggedized connectors 146 include ferrules 148 supporting the second ends 144 of the splitter output optical fibers 140. The ferrules 148 are received within ferrule alignment sleeves 98 of the fiber optic adapters 90. In this way, the splitter output optical fibers 140 can be readily optically connected to the optical fibers corresponding to hardened fiber optic connectors inserted within the hardened outer connector ports 92 of the fiber optic adapters 90.

[0060] Still referring to Figure 9, the secondary fiber optic tether cable 58 of the secondary terminal 50 has the first end 60 coupled to the secondary terminal housing 52 and the opposite second end 62 terminated by the hardened fiber optic connector 64. In one example, the hardened fiber optic connector 64 has the same configuration as the hardened fiber optic connector 120 and is configured to be received within the hardened outer connector port 92 of the fiber optic adapter 90 which forms the demateable fiber optic connector port 30 of the primary terminal 26. In this way, the secondary fiber optic tether cable 58 can be optically connected to the primary terminal 26 in a plug-and-play manner without requiring optical splicing.

[0061] The secondary fiber optic tether cable 58 includes a single secondary tether optical fiber 150 having a first end 152 optically coupled to an input of the passive optical power splitter 54 and a second end 154 supported by a ferrule 156 of the hardened fiber optic connector 64. Inserting the hardened fiber optic connector 64 into the demateable fiber optic connector port 30 of the primary terminal 26, optically couples the single primary tether optical fiber 106 (see Figure 3) of the primary fiber optic tether cable 36 to the single secondary tether optical fiber 150 and also to the input of the passive optical power splitter 54.

[0062] In practice, it may be desirable to initially construct a fiber-to-the-home network by using the primary fiber optic devices 22. For example, the primary fiber optic devices 22 can be installed at the outer edge of a fiber optic network. In this way, the primary fiber optic devices 22 each provide a single demateable fiber optic connector port 30 adapted for allowing subscribers to be connected to the network via fiber optic drop cables routed from the subscriber locations to the single demateable fiber optic connector port 30. The primary fiber optic devices 22 can be installed near to locations of known subscribers or potential subscribers for future expansion opportunities. Because the primary fiber optic devices 22 each have only a single demateable fiber optic connector port 30, it is possible to defer costs associated with building out the network incurred by a large number of unused ports at the initial install of the network. Instead, when new subscribers are desired to be added to the network, the secondary fiber optic devices 24a- 24e can be added to the primary fiber optic devices 22 in the vicinity of the new subscribers. In this way, the port count can be gradually increased by using secondary fiber optic devices with smaller split ratios (e.g., secondary fiber optic devices 24a and 24b), or the port count can be rapidly increased by using secondary fiber optic devices with higher split ratios (e.g., secondary fiber optic devices 24d and 24e) to match growing subscriber demands. This type of configuration allows service providers to effectively use optical line terminals to satisfy customer demand as may be needed or desired. [0063] Figures 10 and 11 show a fiber optic network 10 at initial deployment. As shown in Figure 11, the fiber optic network 10 includes a central office 200 (e.g., a service provider location) where an optical line terminal 202 is located. A primary multi-fiber distribution cable 204 having optical fibers optically coupled to the optical line terminal 202 extends outwardly from the central office 200 and is passed through a plurality of fiber distribution hubs 206.

[0064] As shown in Figure 10, the fiber distribution hubs 206 each include one or more passive optical power splitters 208a-208e. As shown, the passive optical power splitters 208a-208 each have a different optical splitter output. The fiber distribution hubs 206 also include patch panels 210 including arrays of fiber optic adapters and can also include splicing capability. As shown in Figure 11, the fiber distribution hubs 206 provide locations for connecting optical fibers of the primary multi-fiber distribution cables 204 to the optical fibers of secondary multi-fiber distribution cables 212. The connections can be made by splicing or by connectorized patching.

[0065] As shown in Figure 11, the secondary multi-fiber distribution cables 212 are routed outwardly from the fiber distribution hubs 206. The secondary multi-fiber distribution cables 212 are passed through closures 2l4a, 2l4b such as splice closures.

[0066] The primary fiber optic devices 22a-22f can be used to form outer extensions of the fiber optic network 10 that extend from the closures 214a, 214b to the outer edges of the fiber optic network 10 in close proximity to subscriber locations 2l6a-2l6f.

[0067] As shown at Figure 11, the primary fiber optic devices 22a-22f have been installed to extend the fiber optic network 10 to the outer edges. For example, primary fiber optic devices 22a-22c have been installed with the second ends 40 of their corresponding primary fiber optic tether cables 36 optically coupled to optical fibers of the secondary multi-fiber distribution cable 212 at the closure 2l4a.

[0068] In one example, the single primary tether optical fibers 106 can be spliced to the optical fibers of the multi-fiber distribution cable 212 within the closure 2l4a or if connectorized, the single primary tether optical fibers 106 can be connected to the optical fibers of the multi -fiber distribution cable 212 by demateable connections within the closure 2l4a. Similarly, the second ends 40 of the primary fiber optic tether cables 36 of the primary fiber optic devices 22d-22f are optically coupled to optical fibers of the secondary multi-fiber distribution cable 212 at the closure 2l4b.

[0069] The primary terminal 26 of the primary fiber optic device 22a is installed in close proximity to a subscriber location 216a, the primary terminal 26 of the primary fiber optic device 22b is installed in close proximity to a subscriber location 216b, the primary terminal 26 of the primary fiber optic device 22c is installed in close proximity to a subscriber location 2l6c, the primary terminal 26 of the primary fiber optic device 22d is installed in close proximity to a subscriber location 2l6d, the primary terminal 26 of the primary fiber optic device 22e is installed in close proximity to a subscriber location 216e and the primary terminal 26 of the subscriber fiber optic device 22f is installed in close proximity to a subscriber location 2l6f. The subscriber locations can include individual residences, businesses, single family homes, multi-dwelling units, apartment buildings, high rise buildings or other subscriber locations.

[0070] Fiber optic drop cables 2l8a -218f are used to connect the primary fiber optic devices 22a-22f to their respective subscriber locations 216a-216f. The fiber optic drop cables 2l8a-218f can be terminated by hardened fiber optic connectors (such as the hardened fiber optic connector 120 described above), and the fiber optic drop cables 218a- 218f can be coupled to the primary fiber optic devices 22a-22f by inserting the hardened fiber optic connectors into the single demateable fiber optic connector ports 30 of the primary fiber optic devices 22a-22f. As shown at Figure 10, the primary fiber optic devices 22a-22f are optically coupled to a high-split ratio passive optical power splitter 208a within the fiber distribution hub 206 at the initial deployment time.

[0071] Figures 12 and 13 show the fiber optic network 10 of Figures 10 and 11 after the fiber optic network has been upgraded to expand the capacity of the fiber optic network to accommodate more subscribers. For example, the fiber optic network 10 has been expanded to provide expanded service in the regions serviced by the primary fiber optic device 22c and the primary fiber optic device 22e. In this example, the primary fiber optic device 22c is shown servicing a multi-dwelling unit (e.g., subscriber location 216c) where additional residents have requested service. Also, in this examples, additional development has taken place in the vicinity near the primary fiber optic device 22e which has resulted in a need for at least one additional subscriber. [0072] To accommodate the increased demand at the primary fiber optic device 22c, the fiber optic drop cable 2l8c is disconnected from the single demateable fiber optic connector port 30 of the primary fiber optic device 22c. Next, the secondary fiber optic device 24c having a 1x8 splitter is used to expand the capacity of the primary fiber optic device 22c. Specifically, the secondary terminal 50 of the secondary fiber optic device 24c is coupled to the primary terminal 26 of the primary fiber optic device 22c by coupling the secondary exterior mechanical interface 34 of the secondary terminal 50 to the primary exterior mechanical interface 32 of the primary terminal 26. In this way, the secondary terminal 50 is mechanically coupled to the primary terminal 26.

[0073] Next, the hardened fiber optic connector 64 of the secondary fiber optic device 24c is plugged into the single demateable fiber optic connector port 30 of the primary terminal 26. In this way, the optical power splitter 54 of the secondary fiber optic device 24c is optically coupled to the primary fiber optic device 22c and provides an expanded number of splitter output ports 56 for connecting the additional number of subscribers to the fiber optic network 10 via fiber optic drop cables 218c routed from the splitter output ports 56 to the subscriber locations.

[0074] Due to the split ratio being increased at the outer edge of the fiber optic network 10 by coupling the secondary fiber optic device 24c to the primary fiber optic device 22c, it is desirable to reduce the split ratio provided to the primary fiber optic device 22c from the distribution cable 204 routed to the fiber distribution hub 206 to ensure that sufficient optical power is provided to the subscribers at the outer edge of the fiber optic network 10. Thus, as shown in FIG. 12, the primary fiber optic device 22c is uncoupled from the 1x32 optical power splitter 208a, and is optically coupled to a lower split ratio optical power splitter such as the 1x4 optical power splitter 208d.

[0075] The primary fiber optic device 22e can also be upgraded in a similar manner by disconnecting the fiber optic drop cable 2l8e from the single demateable fiber optic connector port 30 of the primary terminal 26 of the primary fiber optic device 22e and installing a secondary fiber optic device to the primary fiber optic device 22e. In the depicted example, only a small amount of growth has occurred in the vicinity of the primary fiber optic device 22e. Thus, a secondary fiber optic device having a smaller split ratio can be selected. In the depicted example, the secondary fiber optic device 24a having a 1x2 splitter is coupled to the primary terminal 26 of the primary fiber optic device 22e and the corresponding secondary fiber optic tether cable 58 of the secondary fiber optic device 24a is plugged into the single demateable fiber optic connector port 30 of the primary terminal 26 of the primary fiber optic device 22e. Thus, two splitter output ports 56 are provided at the location of the primary fiber optic device 22e for coupling subscribers to the fiber optic network 10 via fiber optic drop cables 218e.

[0076] Additionally, due to the split ratio being increased near the outer edge of the fiber optic network 10 where the primary fiber optic device 22e is located, it is desirable to reduce the amount of upstream splitting so that sufficient optical power is provided to the end subscribers where the primary fiber optic device 22e is located. As shown at Figure 12, the primary fiber optic device 22e is optically uncoupled from the passive optical power splitter 208a having a 1x32 split ratio and instead, is optically coupled to the passive optical power splitter 208b having a 1x16 split ratio.

[0077] Another aspect of the present disclosure relates to an automatic device for automatically controlling the uncoupling and coupling between the primary fiber optic devices 22a-22e and the passive optical power splitters 208a-208e.

[0078] In certain examples, the fiber optic system 20 includes a switching matrix 300 (see Figures 10 and 12) positioned within the fiber distribution hub 206. The switching matrix 300 includes an array of optical switches that are controlled by an electronic controller 302. The switching matrix 300 is arranged and configured to selectively connect any one of the passive optical power splitters 208a-208e to any one of the primary fiber optic devices 22a-22f. Thus, the switching matrix 300 is arranged and configured to direct split optical signals received from a passive optical power splitter 208a-208e to the fiber optic drop cables 218a-2l8f leading to subscribers.

[0079] In certain examples, it may be desirable to expand the capacity of a fiber optic network to accommodate more subscribers. As such, an installer may wish to add a secondary fiber optic device 24 including an optical power splitter 54 to the network to expand the capacity of a primary fiber optic device 22. The installer can remotely control the switching matrix 300 in order to transfer a connection from one optical power splitter 208a-208e to another optical power splitter 54.

[0080] In certain examples, an installer can directly control the switching matrix 300 within the fiber distribution hub 206 through a remote connection. For example, the installer can directly control the switching matrix 300 within the fiber distribution hub 206 using a smartphone, although alternatives are possible.

[0081] In certain examples, an installer can remotely communicate with the central office 200 to have the primary fiber optic device 22 and the secondary fiber optic device 24 automatically uncoupled from a passive optical power splitter 208a-208e and automatically coupled to a lower split ratio passive optical power splitter 208a-208e.

[0082] In certain examples, the fiber optic system 20 can automatically detect when a new optical power splitter 54 is installed via a secondary fiber optic device 24. For example, when a new optical power splitter 54 is installed, the switching matrix 300 can automatically adjust the split ratio allowing for sufficient optical power to be provided to the subscribers in view of the increased splitting that occurs at the outer edge of the network. An example of an automatic fiber management system is disclosed by U.S. Patent No. 8,755,688 B2, which is herein incorporated by reference in its entirety.

Claims

What is claimed is:

1. A fiber optic device comprising:

a terminal including a terminal housing and a demateable fiber optic connector port accessible from outside the terminal housing, the terminal housing also including an exterior mechanical interface configured to couple to an add-on splitter module; and

a fiber optic tether cable having a first end coupled to the terminal housing and a second end being remote from the terminal housing, the fiber optic tether cable having an optical fiber configured for optical coupling at the demateable fiber optic connector port of the terminal housing from outside the terminal housing.

2. The fiber optic device of claim 1, wherein the optical fiber includes a

connectorized first end within the terminal housing, wherein the connectorized first end is supported by a non-ruggedized connector, wherein the demateable fiber optic connector port includes a fiber optic adapter including an inner connector port accessible from inside the terminal housing for receiving the non-ruggedized connector, and the fiber optic adapter also including an outer connector port accessible from outside the terminal housing, the outer connector port being configured for receiving a hardened fiber optic connector.

3. The fiber optic device of claim 2, wherein the outer connector port includes a twist-to-lock interface to connect with the hardened fiber optic connector.

4. The fiber optic device of claim 2, further comprising a dust plug to

environmentally seal the outer connector port when not receiving the hardened fiber optic connector, wherein the fiber optic adapter is environmentally sealed relative to the terminal housing, and wherein an environmental seal is provided between the fiber optic adapter and the hardened fiber optic connector when the hardened fiber optic connector is secured within the outer connector port.

5. The fiber optic device of claim 1, wherein the fiber optic tether cable includes an outer jacket surrounding the optical fiber and a reinforcing strength layer including aramid yarn positioned between the optical fiber and the jacket.

6. The fiber optic device of claim 1, wherein the second end of the fiber optic tether cable is either connectorized or splice-ready.

7. A fiber optic system comprising:

a primary fiber optic device including:

a primary terminal including a primary terminal housing and a primary fiber optic adapter including an inner connector port accessible from inside the primary terminal housing and an outer connector port accessible from outside the primary terminal housing, the primary terminal also including a primary exterior mechanical interface; and a primary fiber optic tether cable having a first end coupled to the primary terminal housing and a second end being remote from the primary terminal housing, the primary fiber optic tether cable having a primary tether optical fiber including a connectorized first end received within the inner connector port of the primary fiber optic adapter; and a secondary fiber optic device including:

a secondary terminal including a secondary terminal housing containing an optical power splitter, the secondary terminal including a secondary exterior mechanical interface configured to couple to the primary exterior mechanical interface to mount the secondary terminal housing to the primary terminal housing, the secondary terminal including a plurality of secondary fiber optic adapters having inner connector ports accessible from inside the secondary terminal housing and outer connector ports accessible from outside the secondary terminal housing, the secondary terminal including splitter output optical fibers having first ends optically coupled to an output of the optical power splitter and second ends positioned at the inner connector ports, the second ends of the splitter output optical fibers being connectorized; and

a secondary fiber optic tether cable having a first end coupled to the secondary terminal housing and an opposite second end terminated by a hardened fiber optic connector configured to mate with the outer connector port of the primary fiber optic adapter, the secondary fiber optic tether cable also including a secondary tether optical fiber having a first end optically coupled to an input of the optical power splitter and a second end terminated by the hardened fiber optic connector; and wherein the primary tether optical fiber is optically coupled to the secondary tether optical fiber and an output of the optical power splitter when the hardened fiber optic connector is secured within the outer connector port of the primary fiber optic adapter.

8. The fiber optic system of claim 7, further comprising a plurality of secondary fiber optic devices each having a different optical split ratio.

9. A fiber optic network comprising:

a fiber distribution hub optically coupled to a service provider location by a primary multi-fiber distribution cable, the fiber distribution hub including one or more optical power splitters each having a different optical splitter output;

a secondary multi-fiber distribution cable routed outwardly from the fiber distribution hub, the secondary multi-fiber distribution cable including optical fibers optically coupled to the one or more optical power splitters; and

primary fiber optic devices each including a terminal having a demateable fiber optic connector port accessible from outside the terminal and each including an exterior mechanical interface configured to mechanically couple an add-on splitter module to the terminal of the primary fiber optic device, each primary fiber optic device also including a primary fiber optic tether cable extending outwardly from the terminal, the primary fiber optic tether cables each being optically coupled to one of the optical fibers of the secondary multi-fiber distribution cable.

10. The fiber optic network of claim 9, wherein the primary fiber optic tether cables are optically coupled to the optical fibers of the secondary multi-fiber distribution cable at a closure through which the secondary multi-fiber distribution cable passes through.

11. The fiber optic network of claim 9, further comprising drop cables that extend between the demateable fiber optic connector ports and subscriber locations.

12. The fiber optic network of claim 9, wherein the primary fiber optic devices include first and second primary fiber optic devices, the first primary fiber optic device being optically coupled to a first subscriber location by a drop cable having a hardened fiber optic connector plugged into the demateable fiber optic connector port of the first primary fiber optic device; and

the fiber optic network further comprising an add-on splitter module, the add-on splitter module including an optical power splitter having an output coupled to a plurality of splitter output ports, the add-on splitter module also including a secondary terminal containing the optical power splitter and being mechanically coupled to the terminal of the second primary fiber optic device at the exterior mechanical interface;

wherein an input of the optical power splitter being optically coupled to the second primary fiber optic device by a secondary fiber optic tether cable having a hardened fiber optic connector plugged into the demateable fiber optic connector port of the second primary fiber optic device; and

wherein a drop cable provides an optical connection between one of the splitter output ports of the add-on splitter module and a second subscriber location.

13. The fiber optic network of claim 9, further comprising a plurality of add-on splitter modules at the fiber distribution hub, the plurality of add-on splitter modules including first and second optical power splitters, wherein the first optical power splitter has a higher split ratio than the second optical power splitter, wherein a first primary fiber optic device is optically coupled to a splitter output of the first optical power splitter, and wherein a second primary fiber optic device is optically connected to a splitter output of the second optical power splitter.

14. A method for expanding a fiber optic network, the fiber optic network including a fiber distribution hub including a first optical power splitter, the fiber optic network also including a primary terminal that is remotely positioned with respect to the fiber distribution hub, the primary terminal having a demateable fiber optic connector port accessible from outside the terminal, the demateable fiber optic connector port being coupled to an output of the first optical power splitter, the fiber optic network also including a first drop cable routed from the demateable fiber optic connector port of the primary terminal to a first subscriber location, the method comprising:

disconnecting the first drop cable from the demateable fiber optic connector port of the primary terminal;

mechanically attaching an add-on splitter module to the primary terminal, the add-on splitter module including a secondary terminal housing containing a second optical power splitter, the second optical power splitter including additional splitter output ports coupled to an output of the first optical power splitter;

coupling an input of the second optical power splitter to the demateable fiber optic connector port of the primary terminal;

routing the first drop cable from a first splitter output port of the add-on splitter module to the first subscriber location;

routing a second drop cable from a second splitter output port of the add-on splitter module to a second subscriber location; and

disconnecting the demateable fiber optic connector port of the primary terminal from the output of the first optical power splitter, and subsequently coupling the demateable fiber optic connector port of the primary terminal to an output of a third optical power splitter at the fiber distribution hub, the third optical power splitter having a lower split ratio than the first optical power splitter.

15. The method of claim 14, wherein the step of uncoupling the demateable fiber optic connector port from the output of the first optical power splitter is remotely controlled by a switching matrix to transfer the demateable fiber optic connector port to the output of the third optical power splitter at the fiber distribution hub.