Abstract:
A ferrule for a fiber optic connector includes: a main body extending from a first end to a second end, the main body defining a bore extending from the first end to the second end; an end surface at the second end of the main body; and a raised portion on the end surface, the raised portion extending from the second end and surrounding the bore; wherein an optical fiber is configured to be positioned within the bore of the main body; and wherein the end surface is configured to be polished to remove the raised portion.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
       [0001]    This application is being filed on 18 Mar. 2014, as a PCT International Patent application and claims priority to U.S. Patent Application Ser. No. 61/802,989 filed on 18 Mar. 2013, the disclosure of which is incorporated herein by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates generally to hybrid optical fiber and electrical communication systems. 
       BACKGROUND 
       [0003]    Rapid growth of portable high-speed wireless transceiver devices (e.g., smart phones, tablets, laptop computers, etc.) continues in today&#39;s market, thereby creating higher demand for untethered contact. Thus, there is growing demand for integrated voice, data and video capable of being transmitted wirelessly at data rates of 10 Gbits/second and faster. To provide the bandwidth needed to support this demand will require the cost effective and efficient deployment of additional fixed location transceivers (i.e., cell sites or nodes) for generating both large and small wireless coverage areas. 
       SUMMARY 
       [0004]    One aspect of the present disclosure relates to an architecture that allows both power and communications to be transmitted over one cable to a device for generating a cellular coverage area (e.g., macrocell, microcell, metrocell, picocell, femtocell, etc.). In certain examples, aspects of the present disclosure are particularly advantageous for deploying small coverage area devices (e.g., microcell devices, picocell devices, femtocell devices). 
         [0005]    A further aspect of the present disclosure relates to systems, methods, and devices that facilitate the fast, low cost and simple deployment of optical fiber and power lines to interface with active devices such as devices for generating wireless communication coverage areas (e.g., wireless transceivers) and other active devices (e.g., cameras). 
         [0006]    Still other aspects of the present disclosure relate to systems, methods and devices that facilitate the deployment of wireless communication coverage areas at various locations such as stadiums, shopping areas, hotels, high rise office buildings, multi-dwelling units, suburban environments, corporate and university campuses, in-building areas, near-building areas, tunnels, canyons, roadside areas and coastal areas. 
         [0007]    Still further aspects of the present disclosure relate to systems and methods for enhancing the coverage areas provided by cellular technologies (e.g., GSM, CDMA, UMTS, LTE, WiMax, WiFi, etc.). 
         [0008]    A further aspect of the present disclosure relates to a method for providing electrical power and communication signals to an active device. The method includes converting the electrical power from a first voltage to a second voltage at a first location. The method also includes transmitting the electrical power having the second voltage through a hybrid cable from the first location to a second location, and transmitting the communication signals in an optical form through the hybrid cable from the first location to the second location. The method further includes converting the electrical power to a third voltage at the second location and converting the communication signals from the optical form to an electrical form at the second location. The method additionally includes powering the active device with the electrical power having the third voltage and supplying the communication signals to the active device at the second location. 
         [0009]    A variety of additional inventive aspects will be set forth in the description that follows. The inventive aspects can relate to individual features and to combinations of features. It is to be understood that both the foregoing 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 
         [0010]      FIG. 1  shows a system diagram showing an example distribution of wireless coverage areas deployed using a hybrid cable system in accordance with the principles of the present disclosure; 
           [0011]      FIG. 2  shows hybrid cable system in accordance with the principles of the present disclosure; 
           [0012]      FIG. 3  shows another system in accordance with the principles of the present disclosure; and 
           [0013]      FIG. 4  is a more detailed view of a network interface device of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Various examples will be described in detail with reference to the figures, wherein like reference numerals represent like parts and assemblies throughout the several views. Any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible variations of the inventive aspects disclosed herein. 
         [0015]      FIG. 1  shows a system  10  in accordance with the principles of the present disclosure for enhancing the coverage areas provided by cellular technologies (e.g., GSM, CDMA, UMTS, LTE, WiMax, WiFi, etc.). The system  10  includes a base location  11  (i.e., a hub) and a plurality of wireless coverage area defining equipment  12   a,    12   b,    12   c,    12   d,    12   e  and  12   f  distributed about the base location  11 . In certain example, the base location  11  can include a structure  14  (e.g., a closet, hut, building, housing, enclosure, cabinet, etc.) protecting telecommunications equipment such as racks, fiber optic adapter panels, passive optical splitters, wavelength division multi-plexers, fiber splice locations, optical fiber patching and/or fiber interconnect structures and other active and/or passive equipment. In the depicted example, the base location  11  is connected to a central office  16  or other remote location by a fiber optic cable such as a multi-fiber optical trunk cable  18  that provides high band-width two-way optical communication between the base location  11  and the central office  16  or other remote location. In the depicted example, the base location  11  is connected to the wireless coverage area defining equipment  12   a,    12   b,    12   c,    12   d,    12   e  and  12   f  by hybrid cables  20 . The hybrid cables  20  are each capable of transmitting both power and communications between the base location  11  and the wireless coverage area defining equipment  12   a,    12   b,    12   c,    12   d,    12   e  and  12   f.    
         [0016]    The wireless coverage area defining equipment  12   a,    12   b,    12   c,    12   d,    12   e  and  12   f  can each include one or more wireless transceiver  22 . The transceivers  22  can include single transceivers  22  or distributed arrays of transceivers  22 . As used herein, a “wireless transceiver” is a device or arrangement of devices capable of transmitting and receiving wireless signals. A wireless transceiver typically includes an antenna for enhancing receiving and transmitting the wireless signals. Wireless coverage areas are defined around each of the wireless coverage area defining equipment  12   a,    12   b,    12   c ,  12   d,    12   e  and  12   f.  Wireless coverage areas can also be referred to as cells, cellular coverage areas, wireless coverage zones, or like terms. Examples of and/or alternative terms for wireless transceivers include radio-heads, wireless routers, cell sites, wireless nodes, etc. 
         [0017]    In the depicted example of  FIG. 1 , the base location  11  is shown as a base transceiver station (BTS) located adjacent to a radio tower  24  supporting and elevating a plurality the wireless coverage area defining equipment  12   a.  In one example, the equipment  12   a  can define wireless coverage areas such as a macrocells or microcells (i.e., cells each having a coverage area less than or equal to about 2 kilometers wide). The wireless coverage area defining equipment  12   b  is shown deployed at a suburban environment (e.g., on a light pole in a residential neighborhood) and the equipment  12   c  is shown deployed at a roadside area (e.g., on a roadside power pole). The equipment  12   c  could also be installed at other locations such as tunnels, canyons, coastal areas, etc. In one example, the equipment  12   b,    12   c  can define wireless coverage areas such as microcells or picocells (i.e., cells each having a coverage area equal to or less than about 200 meters wide). The equipment  12   d  is shown deployed at a campus location (e.g., a university or corporate campus), the equipment  12   e  is shown deployed at a large public venue location (e.g., a stadium), and the equipment  12   f  is shown installed at an in-building or near-building environment (e.g., multi-dwelling unit, high rise, school, etc.). In one example, the equipment  12   d ,  12   e,  and  12   f  can define wireless coverage areas such as microcells, picocells, or femtocells (i.e., cells each having a coverage area equal to or less than about  10  meters wide). 
         [0018]      FIG. 2  shows a cable system  100  that can be used to transmit power and communications from a first location  102  to an active device  104  at a second location  106 . The second location  106  is remote from the first location  102 . In certain example, the first location  102  can be a base location and the active device  104  can include wireless coverage area defining equipment. Examples of wireless coverage area defining equipment and locations where such equipment may be installed are described above. Examples of other types of active devices include cameras such as high definition video cameras. 
         [0019]    The first location  102  receives optical signals from a remote location  108  via a fiber optic trunk cable  110 . Optical fibers of the trunk cable  110  can be separated at a fan-out device  111  at the first location. Alternatively, optical power splitters or wavelength division multi-plexers can be used to split optical communications signals from the trunk cable  110  to multiple optical fibers. The fibers can be routed to a patch panel  112  having fiber optic adapters  114  (i.e., structures for optically and mechanically interconnecting two fiber optic connectors  115 ). The first location  102  can also include a combined power/communication panel  116  having fiber optic adapters  117  paired with power adapters  118  (i.e., ports). Connectorized fiber optic patch cords  120  can be routed from the fiber optic adapters  114  to the fiber optic adapters  117 . 
         [0020]    The first location  102  can receive electrical power from a main power line  122 . In one example the main power line  122  can be part of a mains power system that provides 100-240 nominal volt alternating current (example frequencies include 50 and 60 Hertz). The first location  102  can include a converter  124  for converting the electrical power from the first voltage (e.g., 100, 120v, 220v, 230v, 240v etc. nominal voltage) to a second voltage that is less than the first voltage. In one example, the second voltage is less than or equal to 60 volts and less than or equal to 100 Watts such that the output voltage complies with NEC Class II requirements. In one example, the converter  124  is an AC/DC converter that converts the electrical power from alternating current to direct current. Connectorized power cords  126  can be used to route electrical power having the second voltage from the converter  124  to the power adapters  118 . In certain examples, the combined power/communications panel  116  can include at least 18, 24, 30 or 32 fiber optic adapters paired with corresponding power adapters  118 . In certain examples, the converter  124  is large enough to provide NEC Class II compliant power through separate hybrid cables to at least 18, 24, 30 or 32 active devices. Of course, converter having smaller capacities could be used as well. Additionally, the converter  124  can be part of a voltage conversion package including overvoltage protection that provides protection/grounding in the event of lightning strikes and main crosses. 
         [0021]    A hybrid cable  20  can be used to transmit electrical power and optical communication signals between the first and second locations  102 ,  106 . The hybrid cable  20  can include an outer jacket  150  containing at least one optical fiber  152  for carrying the optical communication signals and electrical conductors  154  (e.g., wires such as ground and power wires) for transmitting the electrical power having the second voltage. The hybrid cable  20  can include a first end  156  and a second end  158 . The first end  156  can include a first interface for connecting the hybrid cable to electrical power and fiber optic communication at the first location  102 . In one example, the first interface can include a power connector  160  (e.g., a plug) that connects the electrical conductors  154  to one of the connectorized power cords  126  at the power/communications panel  116 . The power connector  160  can be plugged into the adapter  118  and can be provided at a free end of a cord that extends outwardly from the outer jacket  150  at the first end of the hybrid cable  20 . The cord can contain the electrical conductors  154 . The first interface can also include a fiber optic connector  162  (e.g., an SC connector, LC connector, ST-style connector or other type of connector) that connects the optical fiber  152  to one of the patch cords  120 . The fiber optic connector  162  can plug into one of the fiber optic adapters  117  and can be mounted at the free end of a cord that contains the optical fiber  152  and extends outwardly from the outer jacket  150  at the first end of the hybrid cable  20 . 
         [0022]    The second end  158  of the hybrid cable  20  can include a second interface for connecting the hybrid cable  20  to the active device  104  such that electrical power is provided to the active device  104  and such that fiber optic communication signals can be transmitted between the first and second locations  102 ,  106 . The second interface includes an interface structure  164  including a power connection location  166  and a communication connection location  168 . In one example, the interface structure  164  includes a power converter  170  for converting electrical power carried by the hybrid cable  20  to a direct current third voltage that is less than the second voltage. In one example, the third voltage corresponds to an electrical voltage requirement of the active device  104 . In one example, the power converter  170  is a DC/DC converter. In one example, the third voltage is 12V, 24V or 48V. In examples where AC current is transmitted by the hybrid cable  20 , the power converter  124  can be an AC/AC converter and the power converter  170  can be an AC/DC converter. In certain examples, the interface structure  164  can include an optical-to-electrical converter for converting the communications signals carried by the optical fiber  152  from an optical form to an electrical form. In other examples, optical-to-electrical conversion can be performed by the active device  104  or can take place between the active device  104  and the interface structure  164 . 
         [0023]    In one example, the interface structure  164  includes a converter interface that allows power converters  170  with different conversion ratios to interface and be compatible with the interface structure  164 . The conversion ratio of the particular power converter  170  used can be selected based on factors such as the voltage requirement of the active device  104  and the length of the hybrid cable  20 . The power converters  170  can have a modular configuration can be installed within the interface structure  168  in the field or in the factory. In one example, the power converters  170  can have a “plug-and-play” interface with the interface structure. The modular configuration also allows the power converter  170  to be easily replaced with another power converter  170 , if necessary. In certain examples, the interface structure  164  can include overvoltage protection and grounding arrangements such as fuses, metal oxide varistors, gas tubes or combinations thereof. 
         [0024]    In one example, the electrical power having the third voltage can be output to the active device  104  through the power connection location  166 . The power connection location  166  can include a power connector, a power port, a power cord or like structures for facilitating connecting power to the active device  104 . In one example, the power connection location  166  can have a modular configuration that allows interface connectors having different form factors to be used. 
         [0025]    In one example, the communications signals can be transferred between the hybrid cable  20  and the active device through the communication connection location  168 . The communication connection location  168  can include a connector, a port, a cord or like structures for facilitating connecting to the active device  104 . In one example, the communication connection location  168  can have a modular configuration that allows interface connectors having different form factors to be used. In the case where the optical to electrical converter is provided within the interface structure  164 , the connection location can include electrical communication type connectors (e.g., plugs or jacks) such as RJ style connectors. In the case where the optical to electrical converter is provided at the active device  104 , the communication connection location  168  can include fiber optic connectors and or fiber optic adapters (e.g., SC connectors/adapters; LC connectors/adapters, etc.). In certain examples, ruggedized, environmentally sealed connectors/adapters can be used (e.g., see U.S. Pat. Nos. 8,556,520; 7,264,402; 7,090,407; and 7,744,286 which are hereby incorporated by reference in their entireties. It will be appreciated that when the active devices include wireless transceivers, the active devices can receive wireless signals from the coverage area and such signals can be carried from the active devices to the base station  11  via the hybrid cables. Also, the active devices can covert signals received from the hybrid cables into wireless signals that are broadcasted/transmitted over the coverage area. 
         [0026]    In one example, the second voltage is less than the first voltage and greater than the third voltage. The third voltage is the voltage required by the active device at the second location. In one example, the second voltage is sufficiently larger than the third voltage to account for inherent voltage losses that occur along the length of the hybrid cable. 
         [0027]      FIG. 3  shows another system  210  in accordance with the principles of the present disclosure. The system  210  is adapted for inexpensively providing optical signals and power to a relatively small number of small cell devices  212  (i.e., transceivers). In certain examples, the system  210  provides optical signals and power to only 4, 3 or two small cell devices  212 . In other examples, provides optical signals and power to a single small cell device  212 . 
         [0028]    Referring to  FIG. 3 , the system  210  includes a network interface device  214  which typically includes a housing, box or enclosure that may mount at a subscriber location (e.g., on an exterior wall). The network interface device  214  connects to an interface  216  (e.g., a customer/subscriber interface, a central office interface, etc.) via line  218  such that two-way communication of data, voice and video can be provided between the network interface device  214  and the interface  216 . In certain examples, the line  218  can include a patch cord having connectorized ends that are plugged into corresponding ports provided at the interface  216  and at the network interface device  214 . In other examples, the line  218  can include spliced connections with the interface  216  and/or with the network interface device  214 . In some examples, optical signals are conveyed through the line  218 . In such examples, the network interface device  214  includes structure that optically couples the line  218  to an optical fiber of a hybrid cable  220  routed form the network interface device  214  to a device interface  222  that interfaces with the small cell device  212 . Signals received from the hybrid cable  220  by the small cell device  212  can be wirelessly transmitted by the small cell device  212  to the coverage area. Wireless signals received by the small cell device  212  can be transmitted back through the hybrid cable  220  and the line  218  to the interface  216 . 
         [0029]    In other examples, electrical signals can be conveyed through the line  218 . In such examples, the network interface device  214  can include a media converter (e.g., and electrical to optical converter) for converting the electrical signals received from the interface  216  to optical signals that are conveyed through an optical fiber of the hybrid cable  220  to the device interface  222  that interfaces with the small cell device  212 . The media converter also converts optical signals received from the hybrid cable  220  to electrical signals sent to the interface  216  via the line  218 . Signals received from the hybrid cable  220  by the small cell device  212  can be wirelessly transmitted by the small cell device  212  to the coverage area. Wireless signals received by the small cell device  212  can be transmitted back through the hybrid cable  220  and the line  218  to the interface  216 . 
         [0030]    The network interface device  214  also receives power from a small scale power supply  224 . In one example, the small scale power supply  224  includes a small scale AC/DC converter  226  (e.g., a wall wart type device having a converter brick with an integrated or corded plug) that converts only enough power to support no more than 4, 3, 2 or 1 active devices. In one example, the small scale power supply supports only one active device per each AC/DC converter  226  provided. Thus, separate AC/DC converters  226  can be provided for each active device needed to be powered. In certain examples, each AC/DC converter  226  provides DC voltage that is less than or equal to 60 volts and less than or equal to 100 Watts. Each AC/DC converter  226  can interface with an uninterrupted power supply unit (UPS)  228  that receives power from a mains power system  230  (e.g., a power system/grid having AC power ranging from 100-240 volts). In certain examples, separate UPS  228  units can be provided for each AC/DC converter  226 . The UPS  228  provides a battery back-up so that the power supply  224  continues to provide power for a predetermined amount of time even if power from the mains power system  230  is interrupted. 
         [0031]    The network interface device  214  includes circuitry for electrically connecting the power from the small scale power supply  224  to electrical conductors of the hybrid cable  220 . The electrical conductors of the hybrid cable  220  carry power to the device interface  222  which supplies power to the space cell device  212 . The device interface  222  can include overvoltage protection and can include voltage conversion circuitry. For example, the device interface  222  can reduce the DC voltage from the hybrid cable to a lower voltage compatible with the small cell device  212 . The network interface device  214  also includes circuitry for providing overvoltage protection. In certain examples, the level of overvoltage protection provided by the interface device  214  can be compatible with or equal to the levels of safety and protection of present POTS telephone systems. As depicted at  FIG. 4 , the overvoltage protection provided at the network interface device  214  can include gas discharge tubes  230  that connect to ground when the interior gas is ionized by high voltage, metal oxide varistors  232  that couple to ground in response to voltage surges, and fast acting fuses  234 . It will be appreciated that the various electrical components within the network interface device  214  can be circuit board mounted. 
         [0032]    In certain examples, the AC/DC converter  226  and the UPS  228  are not housed within the housing of the network interface device  214 . Instead a power line  235  directs power from the small scale power supply  224  to the network interface device  214 . Conductors of the power line  235  are coupled to the conductors of the hybrid cable  220  at the network interface device  214 . 
         [0033]    Various modifications and alterations of this disclosure will become apparent to those skilled in the art without departing from the scope and spirit of this disclosure, and it should be understood that the scope of this disclosure is not to be unduly limited to the illustrative examples set forth herein.