Patent Description:
Cellular tower sites are increasingly distributed around the world to provide mobile communications for a variety of devices. Such sites typically include a radio unit connected to an antenna using radio frequency (RF) cabling, where the radio unit is supplied power by an input power cable (e.g., at -<NUM> volts DC) and a return cable back to a power supply located in a shelter. Additionally, data is communicated between one or more base station units (also located in the shelter) and the radio unit over fiber optic cabling.

The cellular site also performs various processing to, for example, determine the appropriate frequency band for a transmission, amplify a signal, transmit and receive signals, etc. In older networks, this type of processing was typically done at the base inside the shelter, but after the introduction of third-generation (<NUM>) and fourth-generation (<NUM>) networks, at least some such processing (e.g., analog/digital conversion) has largely been moved from the base station unit in the shelter to a processing unit located near the top of the cellular tower, since a considerable amount of energy would otherwise be lost via the radio frequency (RF) cable connection between the base station unit and the antenna(s) at the top of the tower.

However, while performing processing at the top of the tower near the antenna helps to minimize energy loss, additional power and fiber optic cabling is required to supply power and data from the shelter to the unit on the tower. Conventional processing units are thus susceptible to damage and disruption from overvoltage and surge current when a lightning strike hits the tower (or nearby). Additionally, towers may host a number of different radio/antenna combinations, thus providing an issue for routing multiple DC link cables to fit the radios, and protecting the connections from overvoltage.

In some cases, hybrid cables are used in cellular sites to combine both fiber and power conductors. Inside such hybrid cables, there are copper wires that feed several radios with power, along with fiber optic cabling to provide a data connection to the radios. Typically, the hybrid cable is terminated in an enclosure and individual surge protectors are provided for each of the DC circuits that feed the radio. The fibers from the fiber optic cabling are terminated inside the enclosure and fiber jumpers are used to connect them to the radios. Likewise, power jumpers are used to connect the power wiring to each radio to the enclosure. An example of a cable breakout assembly is described in <CIT>.

One significant issue arising in conventional cellular sites is that the space available for the fiber optic breakout assembly (and other components) is extremely limited on the cellular tower, and this space is often costly for cellular operators to rent from owners of the tower. Embodiments of the present disclosure address this issue (among others) by providing a hybrid distribution unit that can distribute both power and data connections from a power and fiber cables (or from a hybrid cable containing both power and fiber) within a compact enclosure that helps reduce the overall footprint of the hybrid distribution unit mounted on a cellular tower.

<CIT> discloses a breakout enclosure for distribution power and fiber from a hybrid trunk cable. Two copper bus bars are mounted inside of the disclosure. The bus bars are connected with power conductors of the hybrid cable and with a hybrid connector via further conductors. Moreover, fibers of the hybrid trunk cable are connected to the hybrid connector.

The included drawings are for illustrative purposes and serve to provide examples of possible structures and operations for the disclosed inventive systems, apparatus, methods and computer-readable storage media.

The disclosed embodiments relate to methods and systems for a hybrid distribution unit. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the exemplary embodiments and the generic principles and features described herein will be readily apparent. The disclosed embodiments are mainly described in terms of particular methods and systems provided in particular implementations. However, the methods and systems will operate effectively in other implementations. Phrases such as "one embodiment" and "another embodiment" may refer to the same or different embodiments. The embodiments will be described with respect to systems and/or devices having certain components. However, the systems and/or devices may include more or less components than those shown, and variations in the arrangement and type of the components may be made without departing from the scope of the invention. The disclosed embodiments will also be described in the context of particular methods having certain steps. However, the method and system operate effectively for other methods having different and/or additional steps and steps in different orders that are not inconsistent with the exemplary embodiments.

<FIG> illustrates one example of a power and communication system <NUM> that provides suppression for a distributed wireless communication station. A building <NUM> contains computing equipment for a base transceiver communication station (BTS) <NUM>, which may also be referred to herein as a "baseband unit. " Communication station <NUM> is connected through fiber optic cables <NUM> to different radios <NUM> (also referred to herein as "remote radio units") located on the top of a tower <NUM>. A Direct Current (DC) power plant <NUM> is connected through DC power cables <NUM> to the different radios <NUM> on tower <NUM>. The power plant <NUM> may also be referred to herein as a "power supply unit. " In one example, DC power cables <NUM> include sets of -<NUM> DC volt power cables <NUM>, return power cables <NUM>, and associated ground cables. In one example, power cables <NUM> and fiber optic cables <NUM> are run through a same hybrid trunk cable <NUM> that is routed out of building <NUM> and up tower <NUM> to a hybrid antenna distribution unit <NUM> of the disclosed embodiments.

A local base suppression unit <NUM> may be located inside of building <NUM> and connected to the local ends of power cables <NUM> relatively close to DC power plant <NUM> and communication station <NUM>. In one embodiment, base suppression unit <NUM> is located in a rack <NUM> that also contains DC power plant <NUM>. In another example, base suppression unit <NUM> is located in another rack or some other location next to power plant <NUM>. Examples of base suppression units are described in <CIT>.

Hybrid antenna distribution unit (also referred to herein as a "hybrid distribution unit") <NUM> is attached to a support <NUM> on top of tower <NUM> and is connected to the remote ends of power cables <NUM> and fiber optic cables <NUM> proximate to radios <NUM> and antennas <NUM>. In one example, distribution unit <NUM> is located within <NUM> meters of radios <NUM>. Radios <NUM> may be connected to their respective antennas <NUM> via short RF cables.

The hybrid distribution unit may also be referred to herein as a hybrid fiber to the antenna (FTTA) / power to the antenna (PTTA) distribution unit. As illustrated in <FIG>, the hybrid distribution unit <NUM> may be installed on a mobile communications tower or mast (such as tower <NUM>) to provide for the connection and distribution of the hybrid trunk cable <NUM> to the jumpers <NUM> coupled to the remote radio units <NUM>. As described in more detail, below, the hybrid distribution unit <NUM> also provides integrated over voltage protection (OVP) modules to help protect the remote radio units <NUM> (also referred to herein as "RRUs").

Among other things, hybrid FTTA/PTTA distribution units of the present disclosure help provide higher installation capacity compared to conventional distribution units, as the hybrid distribution units of the present disclosure can support a high number of RRUs in a small footprint. Furthermore, the hybrid distribution units of the present disclosure help simplify deployment and accelerate installations as they can be provided pre-terminated (e.g., no cable connections required in the field).

<FIG> illustrates an interior view of a hybrid antenna distribution unit <NUM> in accordance with some embodiments. Hybrid distribution unit <NUM> includes an enclosure <NUM> having an interior portion as shown. A cable entry and clamping mechanism <NUM> is disposed at the bottom of the enclosure <NUM> and is configured to receive a hybrid trunk cable <NUM> that includes one or more sets of power cables and one or more fiber optic cables. In alternate embodiments, the cable entry and clamping mechanism may be configured to receive separate power and data cables, such as a first trunk cable that includes one or more sets of power cables and a second trunk cable that includes one or more fiber optic cables.

Among other things, the enclosure <NUM> allows both the factory and field installation of the trunk cable(s) to the hybrid distribution unit <NUM>. For example, in some cases the hybrid distribution unit may be pre-wired and terminated during factory assembly such that an installer is not required to make any cable connections in the field. Additionally or alternatively, a user may remove the external dust cover of the hybrid distribution unit <NUM> (described in more detail below) to access the internal portion of the enclosure to add or modify wiring connections.

The enclosure may be sized and dimensioned to effectively route power and data cabling while only requiring a minimal footprint on the cellular tower. As shown in <FIG>, for example, the enclosure is tapered at the bottom such that the width of the top of the enclosure is wider than the width of the bottom. This helps to conserve space while still providing an efficient and effective routing of the cabling that can easily be accessed by installers or maintenance personnel.

The enclosure <NUM> may house one or more overvoltage protection (OVP) modules. In the example shown in <FIG>, OVP modules 215a, 215b, and 215c are disposed at the bottom of the interior portion of the enclosure, with OVP module 215a coupled to a first elongated bus bar 220a extending along a portion of the length of enclosure <NUM> (along the left side of the enclosure) and a second elongated bus bar 220b extending along a portion of the length of enclosure <NUM> parallel to the first bus bar 220a. In this example, the first bus bar 220a is an input power bus bar (-48V in this example) and the second bus bar 220b is a return power bus bar. In <FIG>, a ground plate <NUM> is disposed in the bottom of the enclosure <NUM> and is configured to extend and connect (e.g., through ground wiring) to the OVP modules 215a, 215b, and 215c.

<FIG> provides a more detailed view of the power connections within the enclosure <NUM>. In this example, there are three pairs of elongated bus bars (a -48V bar and corresponding return "RTN" bar) running lengthwise within the enclosure, though in alternate embodiments there may be more or fewer sets of bus bars.

As illustrated in <FIG>, The power conductors of the hybrid (or power) trunk cable are connected to the terminals of the OVP modules 215a, 215b, and 215c at the bottom of the housing. To optimize the cable routing and minimize the assembly and installation time, two bars, -48V and RTN, equipped with lugs are connected to each OVP module and run lengthwise along the housing. For example, OVP 215a is connected to bars 220a and 220b.

As shown in <FIG>, short factory terminated power cables are used for the connection of the bars' lugs to the proper terminals of the hybrid (or power) adaptors. For example, short power cable <NUM> connects the input power connection from adaptor <NUM> to the lug <NUM> on the first bus bar 220a.

The fiber optic portion of the hybrid cable (or the fiber optic cable in case of separate power and fiber optic trunk cables) is routed above the OVP modules through the interior portion of the enclosure <NUM>. <FIG> illustrates the enclosure <NUM> with the addition of fiber optic cable support elements <NUM> coupled to opposite sides of the enclosure. The fiber optic cable support elements <NUM> are configured to retain one or more fiber optic cables using one or more fasteners. In this example, three fiber optic cable support elements <NUM> are depicted running across the width of the enclosure, but in alternate embodiments more or fewer support elements may be used, and the elements may run in any suitable configuration (e.g., lengthwise) in the enclosure.

The fiber optic cable support elements <NUM> allow portions of the fiber optic cables <NUM> to be fastened to the support elements <NUM> using, for example, hook-and-loop fasteners coupled to the support elements <NUM>. The support elements <NUM> are disposed between the fiber optic cabling <NUM> and the removably attachable dust cover (discussed below) to help protect the fiber optic cable against crimping or other damage during the assembly of the housing. <FIG>, <FIG>, and <FIG> are exploded views of the hybrid antenna distribution unit shown in <FIG>.

<FIG> and <FIG> illustrate an example of the exterior portion <NUM> of hybrid distribution unit <NUM>. Portion <NUM> is coupled (e.g., using screws or nuts and bolts around the perimeter of portion <NUM>) to a dust cover <NUM> that encloses and protects the interior portion of the enclosure <NUM>. The dust cover <NUM> may also include (or be coupled to) support brackets <NUM> that allows the hybrid distribution unit <NUM> to be mounted on the cellular tower <NUM>. <FIG> illustrates a cut-away view of the exterior portion of the hybrid distribution unit shown in <FIG> and <FIG>.

As shown in <FIG>, the exterior portion <NUM> includes a plurality of angled tiered platforms <NUM>, with each platform configured to retain a row of adapters <NUM>. In this example, four angled platforms are shown, each with three adaptors per platform, but alternate embodiments may include more or fewer platforms, and more or fewer adaptors per platform. In this example, the plurality of angled tiered platforms <NUM> are angled toward the bottom of the enclosure. Among other things, this assists an installer (usually standing below the hybrid distribution unit <NUM> on a ladder or other support) to connect or disconnect cabling to the adaptors <NUM>.

<FIG> illustrates a detailed view of the terminals of a hybrid adaptor <NUM> that may be used in conjunction with embodiments of the present disclosure. In alternate embodiments, hybrid distribution units of the present disclosure may operate in conjunction with adaptors of any suitable size, shape, and configuration. In the example depicted in <FIG>, adaptor <NUM> includes a pair of power terminals <NUM>, corresponding to an input power terminal and return power terminal as discussed above. The adaptor <NUM> further includes fiber optic connectors <NUM>. The power terminals <NUM> and fiber optic terminals <NUM> connect to the power cables and fiber optic cables, respectively, as shown in the interior view of the hybrid distribution unit <NUM> in <FIG>. For example, power jumper cables (e.g., power jumper cable <NUM>) and fiber optic jumper cables (e.g., fiber optic jumper cable <NUM>) plug into the ends of power terminals <NUM> and fiber optic terminals <NUM>, respectively. <FIG> illustrates an example of a hybrid cable that may be used to connect to the adaptors <NUM>. In this example, the hybrid RRU jumper cable includes supply power (-<NUM>) and return (RTN) power lines, along with fiber optic connectors <NUM>. There are two pairs of fiber optic connectors <NUM> in this example, one pair for the top set of connectors <NUM> and one for the pair for the bottom set of connectors <NUM> shown in <FIG>.

<FIG> illustrates an example of a process for manufacturing a hybrid distribution unit according to various embodiments. The hybrid distribution units of the present disclosure provide a number of advantages over conventional systems. For example, embodiments of the disclosure help provide both overvoltage protection and fiber/power cabling distribution in a small footprint housing. The mechanical design and the use of bars in the interior of the housing allow the reduction of the required volume for the connection of the cables. The hybrid distribution units of the present disclosure provide space for the safe routing of the fiber optic cables, taking into consideration the minimum bend radius requirements, while also protecting the fiber cabling from damage and doing so with a minimal footprint. Additionally, the hybrid distribution units of this disclosure can either factory terminated or installed in the field, and can be configured to be compatible with a variety of hybrid trunk cabling or stand-alone power/fiber cabling.

The figures listed above illustrate examples of embodiments of the application and the operation of such examples. In the figures, the size of the boxes is not intended to represent the size of the various physical components. Where the same element appears in multiple figures, the same reference numeral is used to denote the element in all of the figures where it appears.

Claim 1:
A hybrid distribution unit apparatus comprising:
an enclosure (<NUM>) having an interior portion, exterior portion, a bottom, and a length;
a first elongated bus bar (220a) extending along at least a portion of the length of the interior portion of the enclosure (<NUM>) and configured to connect to a first set of one or more power cables entering the interior portion from the bottom of the enclosure;
a second elongated bus (220b) bar extending along at least a portion of the length of the interior of the enclosure (<NUM>) and configured to connect to a second set of one or more power cables entering the interior portion from the bottom of the enclosure; and
a plurality of adapters (<NUM>) extending from the exterior portion of the enclosure (<NUM>), each adapter (<NUM>) including a first set of one or more connectors (<NUM>) configured to connect one or more power jumper cables to the first and second elongated bus bars (220a, 220b) and a second set of one or more connectors (<NUM>) configured to connect one or more fiber optic jumper cables to the ends of one or more fiber optic cables entering the interior portion of the enclosure from the bottom of the enclosure,
wherein the unit is characterised in that the unit further comprises:
one or more fiber optic cable support elements (<NUM>) coupled to opposite sides of the enclosure and configured to retain one or more fiber optic cables using one or more fasteners, wherein the one or more fiber optic cable support elements are disposed between the one or more retained fiber optic cables and a dust cover (<NUM>) that is removably attachable to the hybrid distribution unit apparatus.