Abstract:
A cell site sector includes: a mounting frame; an RF antenna mounted to one side of the mounting frame; and at least one (RRU mounted to a second, opposed side of the mounting frame md operationally connected with the antenna. The RRU and the RF antenna have horizontal width and depth dimensions, the width dimension art g greater than the depth dimension, wherein the width dimension of the RRU is generally parallel with the width dimension of the RF antenna.

Description:
RELATED APPLICATION 
       [0001]    The present application claims priority from and the benefit of U.S. Provisional Patent Application No. 62/366,395, filed Jul. 25, 2016, the disclosure of which is hereby incorporated herein in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    present inventions relate generally to wireless communications. In particular, they relate to improvements in wireless base station antenna and radio deployments. 
       BACKGROUND 
       [0003]    One known wireless radio network system that may be mounted at the top of the tower comprises a remote radio unit (RRU) and a separate antenna. These components are mounted in separate locations and are then cabled together using jumper cables to pass the radio frequency (RF) signal between them. Such an installation, when done on site, may involve complex and time consuming installations, and may introduce opportunities for installation errors. For example, current installations typically require multiple jumper cables and multiple mounting kits/hardware. This involves substantial installation time (approximately 12-15 hours per site). In addition, doing this installation at the site outdoors in variable temperature and humidity conditions can adversely affect interconnect quality and overall system performance. 
         [0004]    Typically, it is up to the installation team to determine a mounting method. For example, once the antenna and RRU are mounted at the tower top, it is up to the installer to cable and connect the components together correctly. The installer will need a schematic or wiring diagram to understand how such connections should be made. This introduces the possibility of installing cables at the wrong locations, installing cables of incorrect lengths, improperly assembling connectors to the jumper cables, not engaging them correctly, or other installation errors. 
         [0005]    One approach involves the use of a pre-assembled cell site sector. This approach, illustrated in  FIG. 1  and described in detail in WO 2015/095779 (incorporated herein by reference in its, entirety), employs two parallel vertical members  12 ,  14  that are spanned by RRU mounting sites  16  on which RRUs  32  are mounted. The vertical member  12  provides a site for mounting of an antenna  34 , and the other vertical member  14  can be mounted to the leg of an antenna tower or the like. The ability to assemble the entire site remotely, confirm that the connections have been made correctly and test their performance, then mount it in place on an antenna tower, can provide significant time savings for installation. 
       SUMMARY 
       [0006]    As a first aspect, embodiments of the invention are directed to a cell site sector. The cell site sector comprises: a mounting frame; an RF antenna mounted to one side of the mounting frame; and at least one (RRU mounted to a second, opposed side of the mounting frame and operationally connected with the antenna. The RRU and the RF antenna have horizontal width and depth dimensions, the width dimension being greater than the depth dimension, wherein the width dimension of the RRU is generally parallel with the width dimension of the RF antenna. 
         [0007]    In some embodiments, three cell site sectors are mounted to a tri-sector frame having three vertical mounting members, wherein each of the cell site sectors is mounted to a respective one of the vertical mounting members. 
         [0008]    In other embodiments, the mounting frame comprises a backplane. The backplane may include connectors configured to connect with the RRU. A fiber/power distribution unit mounted to the second side of the backplane. In some embodiments, the RRU includes connectors, and the RRU connectors are blind-mated to connectors mounted on the backplane. 
         [0009]    In additional embodiments, the mounting frame further comprises a subfloor attached to the backplane, wherein the antenna is mounted to the subfloor and the RRU is mounted to the backplane. Other components, such as a battery, an RF conditioning unit, a fiber/power distribution unit (including at least one of a voltage regulator, a power redundancy circuit, and an overvoltage protection unit) may be mounted on the backplane. 
         [0010]    The mounting frame may also include baffling to promote cooling. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0011]      FIG. 1  is a side view of a prior pre-assembled cell site sector. 
           [0012]      FIG. 2  is a perspective view of a pre-assembled cell site sector according to embodiments of the invention. 
           [0013]      FIG. 3  is an enlarged perspective view of the tap portion of the cell site sector of  FIG. 2 . 
           [0014]      FIG. 4  is a side view of another pre-assembled cell site sector according to additional embodiments of the invention. 
           [0015]      FIG. 5  is a top view of three cell site sectors of  FIG. 4  mounted to a tri-sector fame. 
           [0016]      FIG. 6  is a perspective view of the frame of  FIG. 5 . 
           [0017]      FIG. 7  is a perspective view of the cell site sectors and frame of  FIG. 5 . 
           [0018]      FIG. 8  is a perspective view of two tri-sector frames and cell site sectors mounted on the top of a pole. 
           [0019]      FIG. 9  is a perspective view of three cell site sectors of  FIG. 4  mounted to a monopole with mounting brackets. 
           [0020]      FIG. 10  is a perspective view of a backplane-based cell site sector according to additional embodiments of the invention. 
           [0021]      FIG. 11  is an exploded perspective view of a backplane-based cell site sector according to additional embodiments of the invention. 
           [0022]      FIG. 12  is an enlarged exploded perspective view of one end of the cell site sector of  FIG. 11 . 
           [0023]      FIG. 13  is a perspective view of a backplane-based cell site sector covered by a cover panel according to further embodiments of the invention. 
           [0024]      FIG. 14  is an exploded perspective view of the cell site sector and cover panel of  FIG. 13 . 
           [0025]      FIG. 15  is a perspective view of cell site sectors of  FIG. 11  mounted on an upper story of a building, with reflective film on two of the cell site sectors to encourage “blending” with the environment. 
           [0026]      FIG. 16  is a perspective view of the cell site sector of  FIG. 11  with an AC-DC converter module mounted thereon. 
           [0027]      FIG. 17  is a perspective view of the cell site sector of  FIG. 11  illustrating how the cell site sector could be provided in modular fashion. 
           [0028]      FIG. 18  is a perspective view of an RRU for a cell site sector of  FIG. 11  being transported by a drone. 
           [0029]      FIG. 19  is a perspective view of the drone and RRU of  FIG. 18  hovering for remote installation of the RRU onto an existing cell site sector. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]    The present invention is described with reference to the accompanying drawings, in which certain embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments that are pictured and described herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It will also be appreciated that the embodiments disclosed herein can be combined in any way and/or combination to provide many additional embodiments. 
         [0031]    Unless otherwise defined, all technical and scientific terms that are used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the below description is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in this disclosure, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that when an element (e.g., an assembly, a housing, a cable, etc.) is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. 
         [0032]    Referring now to the drawings, a cell site sector according to embodiments of the invention, designated broadly at  110 , is shown in  FIG. 2-4 . The cell site sector  110  includes a single vertical mounting member  112  (typically formed of aluminum) on which an antenna  134  and three RRUs  132  are mounted. The vertical member  112  may have a cross-section that is round, square (which can provide increased wind load resistance) or another shape as desired. Two horizontal members  114  are fixed to the vertical mounting member  112  and extend rearwardly (i.e., away from the antenna  134 ). Each of the horizontal members  114  has a clamp  136  on its free end; each clamp  136  has two clamp brackets  138 ,  140  that may be clamped together via bolts  142 . The clamps  136  are employed to mount the cell site sector  110  to a mounting structure such as an antenna tower or the like (see  FIG. 4 , which illustrates the clamps  136  mounted to a vertical adapter pipe  118  that is mounted to an antenna tower  119  via U-bolts  121 ). Note that the upper horizontal member is shown at  114  in  FIG. 2 , at  114 ′ in  FIG. 3 , and at  114 ″ in  FIG. 4  to illustrate three different locations on the vertical member  112 . 
         [0033]    Two mounts  126  are fixed to the front surface of the vertical member  112  and provide mounting locations for the antenna  134  (see  FIG. 4 ). Four horizontal mounts  120  are fixed to the, rear surface of the vertical member  112  and provide mounting locations for the three RRUs  132  and for fiber/power distribution and RF signal combining units  122 ,  124  ( FIGS. 2 and 4 ). Notably, the mounts  120  are configured so that each RRU  132  is oriented with its width dimension (i.e., the larger of its horizontal dimensions) generally parallel with the width dimension of the antenna  134 , and its depth dimension (i.e., the smaller of its horizontal dimensions) generally perpendicular to the width dimension of the antenna  134 . In this orientation, the cell site sector  110  may experience a reduced wind load compared to prior cell site sectors, as winds blowing parallel to the width direction face a reduced surface area from the RRUs  132 , and winds perpendicular to the width direction are blocked from the RRUs  132  by the antenna  134  (or from the antenna  134  by the RRUs  132 ). 
         [0034]    Referring again to  FIG. 4 , the vertical adapter pipe  118  used to mount the cell site sector  110  to the antenna tower  119  has a safety stop collar  127  at its lower end. The adapter pipe  118  serves as an axis of azimuth rotation A for the cell site sector  110 . The safety stop collar  127  is configured to prevent the cell site sector  110  from slipping off of the lower end of the adapter pipe  118  when the clamps  136  are loosened to allow for azimuth adjustment of the antenna  134 . 
         [0035]    As shown in  FIG. 3 , the cell site sector  110  may have a lifting hoist flange  144  located at the upper end of the vertical member  112 . The hoist flange  144  (or other hoisting device) may be positioned at or near the vertical center of gravity of the cell site sector  110  to reduce rocking, swaying, twisting or the like during hoisting of the cell site sector  11  during installation. 
         [0036]    Referring now to  FIGS. 5-7 , a tri-sector assembly  150  is shown therein. The assembly  150  includes three cell site sectors  110  largely as described above. The cell site sectors  110  are mounted to a frame  160  (best seen in  FIG. 6 ) that includes three vertical members  162  spanned by numerous braces  164  that form a triangular pattern. End plates  166  are attached at the upper and lower ends of the vertical members  162 .  FIG. 5  shows that the cell site sectors  110  may he mounted to the vertical members  162  of the frame  160  via clamps  136  as shown in  FIG. 4 . Alternatively, as shown in  FIG. 7 , each of the three cell site sectors  110  nay be mounted to a respective vertical member  162  via U-bolts  168  inserted into a plate  167  mounted on the ends of the horizontal members  114 . 
         [0037]      FIG. 7  illustrates the assembly  150  mounted atop a pole or tower  170 . Notably, the tri-sector assembly  150  can be fully assembled on the ground, then hoisted in its entirety to the top of a structure for mounting.  FIG. 8  illustrates two tri-sector assemblies  150  mounted in vertically stacked fashion on top of the pole/tower  170 . Such an arrangement may he particularly advantageous if different cell site operators own and deploy each of the tri-sector assemblies  150 . 
         [0038]      FIG. 9  illustrates a tri-sector assembly  150 ′ that is mounted on a monopole  180 . The assembly  150 ′ includes three cell site sectors  110  with vertical adapter poles  114 . Each of the adapter poles  114  is mounted to a respective pair of six brackets  171  that are secured with horizontal bolts  172  to form two mounting rings  174 . The mounting rings  174  are then secured onto the monopole  180  at a desired height. As with the assembly  150 , the assembly  150 ′ can be fully assembled on the ground and hoisted in its entirety for mounting on the monopole  180 . 
         [0039]    Referring now to  FIG. 10 , another cell site sector, designated broadly at  210 , is shown therein. The cell site sector  210  includes an antenna  234 , three RRUs  232 , and a fiber/power distribution unit  236 . These are all mounted to a structural backplane  238 , which replaces the vertical member, horizontal members, mounts, etc. of the cell site sector  110  as a mounting frame, with the RRUs  232  and fiber/power distribution unit  236  mounted on one side of the backplane  238 , and the antenna  234  mounted on the opposite side. Mounting features for mounting the RRUs  232  and the antenna  234  onto the backplane  238  are integrated into the backplane  238 . 
         [0040]    The backplane  238  includes three sets of connectors  240 . Each of the RRUs  232  is mounted to the backplane  238  adjacent the connectors  240 , such that connectors  242  on each RRU  232  can be connected to the adjacent set of connectors  240  via jumper cords  244 . The antenna  234  is connected to mating connectors (not shown) on the opposite side of the backplane  238  via jumper cables (also not shown). In this manner the RRUs  232  are connected to the antenna  234 . The short length of jumper cords  244  can improve signal propagation, and the proximity of the connectors  242  of the RRUs  232  to the connectors  240  of the backplane  238  can reduce the risk of incorrect connections. 
         [0041]    The fiber/power distribution unit  236  is mounted directly to the backplane  238 . Three hybrid fiber/&#39;power connectors  246  are located on the lower end of the fiber/power distribution unit  236  to receive cables routed from the ground. In some embodiments, the connectors  246  may be separate power and fiber connectors to receive separate fiber and power cables routed from the bottom of the tower. 
         [0042]    A horizontal mounting bar  248  extends from the fiber/power distribution unit  236  to a mounting panel  250  with U-bolts  252 . A horizontal mounting bar  254  extends rearwardly from the opposite end of the backplane  238 . A mounting panel  256  with U-bolts  258  is attached to the free end of the mounting bar  254 . The cell site sector  210  can be mounted to an antenna tower or the like via the U-bolts  252 ,  258  in much the manner described above. 
         [0043]    Referring now to  FIGS. 11 and 12 , another embodiment of a cell site sector, designated broadly at  310 , is illustrated therein. The cell site sector  310  includes an antenna  334 , three RRUs  332 , a structural backplane  338  to which the RRUs  332  mount, and further includes a subfloor  340  that is sandwiched between the antenna  334  and the backplane  338 . The subfloor  340  is spaced from and sealed to the backplane  338  to form a cavity  339 . These components are described in greater detail below. 
         [0044]    In addition to being structurally mounted to the backplane  338 , each of the RRUs  332  is electrically connected directly to connectors  342  mounted in the backplane  338 . Each RRU  332  includes connectors (for example, connectors that satisfy the “4.3/10” standard proposed by the International Electrical Commission (46F/243/NP)) that blind mate with the connectors  342  mounted on the backplane  338 . Exemplary connectors include, for example, those described in U.S. patent application Ser. No. 14/594,727, filed Jan. 12, 2015, and U.S. patent application Ser. No. 15/141,526, filed Apr. 28, 2016, the disclosures of which are hereby incorporated herein by reference in their entirety. In some embodiments, the blind mating connection may occur with the RRUs  332  simply being slid into place along a direction normal to the backplane  338  (see the arrows in  FIG. 11 ). An exemplary configuration is shown in U.S. Patent Publication No. 2016/0104969, filed Oct. 8, 2015, the disclosure of which is hereby incorporated herein in its entirety. 
         [0045]    Antenna interface connections  344  are mounted to the subfloor  340  to enable interconnection with the antenna  334 . The cavity  339  between the subfloor  340  and the backplane  338  allows room for cables to extend between the connectors  342  and the antenna interface connections  344 . The subfloor  340  also serves as a potential mounting location for RF conditioning components  346 , such as RF combiners, RF diplexers, RF filters, and the like. 
         [0046]    A fiber/power distribution unit  337  is mounted on the backplane  338  ( FIG. 12 ). The fiber/power distribution unit  337  includes connectors  339  on its lower surface to receive cables routed up the tower. In addition to the conventional fiber/power distribution components typically found in such a unit, the fiber/power distribution unit  337  may also include other components that can improve/facilitate performance of the cell site sector  310 . Such components may provide voltage regulation, power redundancy, overvoltage protection, and the like. Any of all of these components may be configured to be replaceable in a “plug and play” manner. Exemplary components are discussed in U.S. Provisional Patent Application Nos. 62/280,549, filed Jan. 19, 2016, and 62/256,318, filed Nov. 17, 2015, the disclosures of which are hereby incorporated herein in their entirety. 
         [0047]    Referring now to  FIGS. 13 and 14 , a backplane-based cell site sector  410  is illustrated therein that includes an optional cover panel  450  that overlies the backplane  438  and contacts the antenna  434 . The cover panel  450  has ventilation perforations  452  at each end that allow air to flow through the cavity created beneath the cover panel  450  in a directed manner. In some embodiments, baffling  456  is included near and between the RRUs  432  to direct air flow within the cavity, providing some cooling for heat-sensitive components, such as the RRUs  432 . The perforations  452  should be sized to provide adequate air flow, but prevent insect and/or animal intrusion. 
         [0048]      FIGS. 13 and 14  also illustrate a cable cover  458  that compliments the cover panel  450  at the lower end of the cell site sector  410 . The cable cover  458  provides shelter for cables  460  routed to the RRUs  432  from the fiber/power distribution unit  436 , as well as any cables  462  routed from the RRUs  432  to the antenna  434 . 
         [0049]      FIG. 15  illustrates that a cover panel and/or an antenna itself may be covered with a reflective film that can “match” the cell site sector color to the sky or background. Such a covering (seen in antenna  534  in FIG,  15 , but not in antenna  534 ′) can provide some degree of camouflage to enable an antenna to blend in with its surroundings for aesthetic reasons. 
         [0050]      FIG. 16  illustrates an alternative cell site sector  610  that includes a battery module  664  mounted in a position occupied by an RRU in embodiments discussed above (the cell site sector  610  still includes two RRUs  632  in other positions). The presence of the battery module  664  can provide reserve capacity to power the RRUs  632  in the event of a grid power failure. Because the battery module  664  is located at the top of the antenna tower (rather than at the base of the tower as is typical), opportunities for theft are reduced considerably, and lower line losses are present due to a much shorter cable length from battery to RRU.  FIG. 16  also illustrates an integrated AC-DC converter  666  attached to (or integrated with) the battery module  664  that accepts AC power at the top of the tower and delivers steady state or backup power to the RRUs  632 . Locating the AC-DC converter  666  at the top of the tower provides AC power at the top of the tower (rather than at the bottom of the tower), thereby reducing energy losses. 
         [0051]      FIG. 17  illustrates a modular cell site sector  710  that includes one RRU  732  and one antenna  734  per module  733 . The lowermost module  733  includes the fiber/power distribution unit  737  (potentially with the components discussed above with respect to unit  337  discussed above) as well as the RF conditioning components  746  mounted on the subfloor  740 . Subsequent modules  733  can be added later (likely in a stacked fashion as illustrated) and can utilize the fiber/power distribution unit  737  and the RF conditioning components  746  of the lowermost module  733 . 
         [0052]      FIGS. 18 and 19  illustrate one of the potential advantages of the “plug and play” nature of the RRUs of the cell site sectors discussed in  FIGS. 11-17 . For the purposes of installing, or replacing, an RRU  832  in a cell site sector  810 , a flighted drone  870  may be employed to both transport an old RRU  832  from the cell site sector  810  as it is mounted on the top of the tower and convey a new RRU  832  from the ground to the top of the tower and mount it thereon. Such operations may be much quicker and less expensive than requiring a technician to scale the tower to perform such a replacement operation. 
         [0053]    It should also be noted that the cell site sectors discussed above may be combined with a system for adjusting the beam of the antennas mounted thereon, whether the systems are manually adjusted, automatically adjusted, or even adjusted in real time. Such systems are discussed, for example, in U.S. Provisional Patent Application No. 62/331,703, filed May 4, 2016, the disclosure of which is hereby incorporated herein by reference in its entirety. 
         [0054]    The several embodiments of cell sector radio assemblies and their components described herein and/or shown in the drawings are presented by way of example only and are not limiting as to the scope of the invention. Unless otherwise specifically stated, individual aspects and components of the cell sector radio assemblies may be modified without departing from the scope and spirit of the invention.