Patent Publication Number: US-11644631-B2

Title: Sealed optical fiber terminal

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application Ser. No. 62/740,135 filed Oct. 2, 2018, which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to optical fiber communications, and more specifically to sealed optical fiber terminals. 
     BACKGROUND 
     Data, voice, and other communication networks are increasingly using fiber optics to carry information. In a fiber optic network, each individual fiber is generally connected to both a source and a destination device. Additionally, along the fiber optic run between the source and the destination, various connections or couplings may be made on the optical fiber to adjust the length of the fiber or to provide termination connection ports for end users at which one or more fibers may be branched from a feed cable. In instances when the connection may be exposed to weather conditions, an essentially waterproof configuration of components is needed. 
     To interconnect the cables, various cable connector designs provide for low insertion loss and stability. Some example connectors may include, but are not limited to, SC, Dual LC, LC, ST and MPO connectors. In most of these designs, ferrules (one in each connector, or one in the connector and one in the apparatus or device), each containing an optical fiber end, are butted together end to end and light travels across the junction. 
     With the increasing desire for completely optical networks, “fiber to the premises” (FTTP) or “fiber to the home” (FTTH) systems are being developed to provide optical fibers that extend from the source to the site of the end-user. For this purpose, optical connection terminals are needed for interconnection of various lines with drop cables that extend to user locations. Further, there is a need for flexible, customizable fiber distribution systems that may be easily expanded or reconfigured. 
     SUMMARY 
     In at least some embodiments, the present disclosure describes a sealed terminal. The sealed terminal includes a housing including an interior compartment. The sealed terminal also includes a cover connected to the housing to close the interior compartment. The cover includes a plurality of input ports for receiving one or more cables, and an output adapter module including a plurality of distribution ports each for receiving a connector for active connection to the one or more cables. The sealed terminal additionally includes a splice tray positioned in the interior compartment and including one or more cable retainers configured to route the one or more cables within the interior compartment. The sealed terminal further includes an adapter plate connected to the splice tray and including a plurality of adapters for connecting the one or more cables to the plurality of distribution ports. The sealed terminal also includes a splice chip connected to the splice tray and including a plurality of slots for receiving and routing at least one of the one or more cables. 
     According to some disclosed embodiments, the housing includes a distal end having a radiused wall for routing the one or more cables within the interior compartment without bending of the one or more cables. 
     According to some disclosed embodiments, the splice tray includes a radiused wall parallel to the radiused wall of the housing. 
     According to some disclosed embodiments, the one or more cables is a flat drop cable. 
     According to some disclosed embodiments, the one or more cables is a round drop cable. 
     According to some disclosed embodiments, the plurality of distribution ports comprise flexible ports. 
     According to some disclosed embodiments, the flexible port comprises a seal, a press-in element, and a clip. 
     According to some disclosed embodiments, the connector is a round plug-in connector configured to contact the seal. 
     According to some disclosed embodiments, the splice tray comprises a first cavity and a second cavity separated by an interior support wall. 
     According to some disclosed embodiments, the first cavity and the second cavity are formed by a perimeter wall surrounding and perpendicular to the interior support wall. 
     According to some disclosed embodiments, the perimeter wall is radiused for routing the one or more cables within the interior compartment without bending of the one or more cables. 
     According to some disclosed embodiments, splice chip is connected to the interior support wall. 
     According to some disclosed embodiments, the splice chip includes chip ends at edges of a base of the splice chip and the interior support wall comprises a plurality of undercuts configured to receive the plurality of chip ends so as to couple the splice chip to the splice tray. 
     According to some disclosed embodiments, the plurality of adapters correspond to the plurality of distribution ports. 
     According to some disclosed embodiments, the adapter plate includes four adapters and the output adapter includes four distribution ports. 
     According to some disclosed embodiments, the adapter plate includes twelve adapters and the output adapter includes twelve distribution ports. 
     According to some disclosed embodiments, the one or more cable retainers include a plurality of prongs for contacting at least one of the one or more cables. 
     According to some disclosed embodiments, the one or more cables include at least one input cable and a plurality of spliced cables connected to the at least one input cable and being greater in number than the at least one input cable. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG.  1 A  is a perspective view of one embodiment of a terminal configured according to aspects of the present disclosure; 
         FIG.  1 B  is a perspective view of the terminal of  FIG.  1 A , further showing incoming cables according to aspects of the present disclosure; 
         FIG.  2 A  is a perspective view of another embodiment of a terminal configured according to aspects of the present disclosure; 
         FIG.  2 B  is a perspective view of the terminal of  FIG.  2 A , further showing incoming cables according to aspects of the present disclosure; 
         FIG.  3    is a perspective view of the terminal of  FIG.  2 A , further showing connectors installed in the ports according to aspects of the present disclosure; 
         FIG.  4 A  is a front view of one embodiment of a cover having ports configured according to aspects of the present disclosure; 
         FIG.  4 B  is a front view of another embodiment of a cover having ports configured according to aspects of the present disclosure; 
         FIG.  5    is a perspective view of the terminal of  FIG.  2 A , further showing the interior compartment according to aspects of the present disclosure; 
         FIG.  6    is a perspective view of one embodiment of a flexible port (FlexPort) according to aspects of the present disclosure; 
         FIG.  7    is a perspective view of the terminal of  FIG.  2 A , further showing a splice chip in the interior compartment according to aspects of the present disclosure; 
         FIG.  8 A  is a top view of one embodiment of a splice chip configured according to aspects of the present disclosure; 
         FIG.  8 B  is a perspective view of the splice chip of  FIG.  8 A ; 
         FIG.  8 C  is a cross-sectional side view of the splice chip of  FIG.  8 A ; 
         FIG.  9    is a close-up view of a splice chip showing stacked loose tube fiber splices disposed therein according to aspects of the present disclosure; 
         FIG.  10 A  is an exploded perspective view of an optical fiber cassette having a loose tube fiber splice chip configured according to aspects of the present disclosure; 
         FIG.  10 B  is a perspective view of the optical fiber cassette of  FIG.  10 A ; 
         FIG.  11 A  is a top view of the splice tray of the optical fiber cassette of  FIG.  10 A  having a single splice chip according to aspects of the present disclosure; 
         FIG.  11 B  is a top view of the splice tray of the optical fiber cassette of  FIG.  10 A  having two splice chips according to aspects of the present disclosure; 
         FIG.  12 A  is a side view of a portion of a splice tray configured for receiving a splice chip according to aspects of the present disclosure; and 
         FIG.  12 B  is a side view of the splice tray of  FIG.  12 A  with the splice chip inserted therein according to aspects of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Aspects of the present disclosure provide sealed optical fiber terminals and components that are flexible and customizable. Terminals may be configured differently and customized according to service provider and customer needs. 
     Various embodiments provide multiple distribution ports. For example, one embodiment may provide four distribution ports. Another embodiment may provide twelve distribution ports. Various embodiments may accept different types of cables, such as flat drop cable or round drop cable. 
     In some embodiments, the interior compartment of the terminal may incorporate fiber management and bend-radius protection into the design. The unique shape of the interior compartment of the terminal may control fiber bends. Various embodiments may have adapters and may further include a splice tray and a splice chip. 
     The present disclosure is not limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. 
       FIG.  1 A  is a perspective view of one embodiment of a terminal  100 . The terminal  100  includes a housing  102  and a cover  104  configured to couple to the housing of the terminal. The cover  104  may include one or more protrusions  106  having openings  108  configured to receive tabs  110  located on the housing so as to snap the cover to the housing. In other embodiments, the tabs  110  may be located on the cover and the openings  108  may be placed on the housing  102 . In yet other embodiments, other types of coupling and locking mechanisms may be used to lock the cover to the housing. For example, latches, bolts, clips, seals, or other locking mechanisms may be used. In some embodiments, the cover  104  may be removable. In other embodiments, the cover  104  may be hinged to the housing  102  such that it is movable with respect to the housing. 
     The cover  104  may include a plurality of ports, including incoming cable ports  112  and distribution ports  114 . In this example, the terminal  100  includes 12 distribution ports. Although the embodiment of  FIG.  1 A  shows two incoming cable ports  112  and 12 distribution ports  114 , other embodiments may include a different number of each type of port. In one example, each incoming cable port  112  may be a sealed port, and each distribution port  114  may be a sealed port. Each distribution port  114  may have a breakoff cap. In some embodiments, the distribution ports  114  may have anti-rotation locking features. The distribution ports  114  may be Clearfield FlexPorts. The ports  112  and  114  may include knock-out covers that can be removed once a port  112  and  114  is used. The ports may also be arranged in a different configuration than the embodiment shown in  FIG.  1 A . 
       FIG.  1 B  is a perspective view of the terminal  100  of  FIG.  1 A , further showing incoming cables  116  inserted into the incoming cable ports  112 . The incoming cables  116  are round cables. In other embodiments, the terminal may be configured to receive other types of cables such as a flat drop cable, as shown and described below in relation to  FIG.  2 B . 
       FIG.  2 A  is a perspective view of another embodiment of a terminal  120 . The terminal  120  includes a housing  122  and a cover  124  configured to couple to the housing of the terminal. The cover  124  may include one or more protrusions  126  having openings  128  configured to receive tabs  130  located on the housing so as to snap the cover to the housing. In other embodiments, the tabs  130  may be located on the cover and the openings  128  may be placed on the housing  122 . In yet other embodiments, other types of coupling and locking mechanisms may be used to lock the cover to the housing. For example, latches, bolts, clips, seals, or other locking mechanisms may be used. In some embodiments, the cover  124  may be removable. In other embodiments, the cover  124  may be hinged to the housing  122  such that it is movable with respect to the housing. 
     The cover  124  may include a plurality of ports, including incoming cable ports  132  and distribution ports  134 . In this example, the terminal  120  includes 4 distribution ports. Although the embodiment of  FIG.  2 A  shows two incoming cable ports  132  and 4 distribution ports  134 , other embodiments may include a different number of each type of port. In one example, each incoming cable port  132  may be a sealed port, and each distribution port  134  may be a sealed port. Each distribution port  134  may have a breakoff cap. In some embodiments, the distribution ports  134  may have anti-rotation locking features. The distribution ports  134  may be Clearfield FlexPorts. The ports  132  and  134  may include knock-out covers that can be removed once a port  132  and  134  is used. The ports may also be arranged in a different configuration than the embodiment shown in  FIG.  2 A . 
       FIG.  2 B  is a perspective view of the terminal  120  of  FIG.  2 A , further showing incoming cables  136  inserted into the incoming cable ports  132 . The incoming cables  136  are flat drop cables. In other embodiments, the terminal may be configured to receive other types of cables such as a round cable, as shown and described above in relation to  FIG.  1 B . 
       FIG.  3    is a perspective view of the terminal  120  of  FIG.  2 A , further showing connectors  140  installed in the distribution ports  134 . In various embodiments, the distribution ports  134  may be Clearfield FlexPorts and the connectors  140  may be Clearfield Flex Connectors. 
       FIG.  4 A  is a front view of one embodiment of a cover  142  having two incoming cable ports  144  and four distribution ports  146 . Other embodiments may include a different number of each type of port. Each of the incoming cable ports  142  and the distribution ports  144  may be a sealed port. The incoming cable ports  144  are configured to receive round cables. In some embodiments, each of the incoming cable ports may be configured to accept multiple cable types. The cover  142  further includes protrusions  148  having openings  150  configured to receive respective tabs of a terminal housing to couple the cover to the housing. 
       FIG.  4 B  is a front view of another embodiment of a cover  152  having an incoming cable port  154  and twelve distribution ports  156 . Other embodiments may include a different number of each type of port. The incoming cable port  154  is configured to receive a flat drop cable. Each of the incoming cable port  154  and the distribution ports  156  may be a sealed port. The cover  152  further includes protrusions  158  having openings  160  configured to receive respective tabs of a terminal housing to couple the cover to the housing. In various embodiments disclosed herein, each distribution port, such as distribution ports  146  and  156 , may have a respective entrance tab disposed within the cover or the housing of the terminal. The entrance tabs must be broken off to use the respective ports. 
       FIG.  5    is a perspective view of the terminal  120  of  FIG.  2 A , further showing the interior compartment  162 . The interior compartment  162  includes at least one adapter plate  164 . The adapter plate  164  may include a plurality of adapters. The adapters may correspond to the distribution ports  134 . For example, the adapter plate  164  includes 4 adapter slots  166 , each slot corresponding to a respective one of the 4 distribution port  134 . Other embodiments may comprise a different number of ports and adapters slots. 
     The interior compartment  162  has a unique shape configured to control fiber bends. The interior compartment  162  is further configured to hold at least one fiber splice tray  168 . In some embodiments, the terminal  120  may include a module or cassette having splice and fiber management area. The cassette may be configured to terminate the fiber that runs into the terminal  120 . Various embodiments may include different types or configurations of cassettes. In various embodiments, the interior compartment may provide slack storage capacity. A splice tray may comprise a plurality of prongs  169  for fiber management and storage. 
     In various embodiments disclosed herein, the plurality of distribution ports may be configured to be sealed ports. In one embodiment, each distribution port may be sealed by installing a flexible port (Clearfield FlexPort) therein.  FIG.  6    is a perspective view of one embodiment of a flexible port  170  (FlexPort). The flexible port  170  comprises a seal, such as an O-Ring  172 , a press-in element  174  and a clip  176 . In some embodiments, a flexible port  170  may be pre-installed within the distribution ports  134  of the terminal  120 . In other embodiments, a flexible port  170  may be installed in the field. A flexible port  170  may be installed by placing the seal or O-ring  172  into the desired port hole, placing the press-in element  174  into the hole, and installing the clip  176  into the press-in element. The flexible ports  170  may further comprise entrance tabs that must be broken off prior to usage of the flexible ports. 
     In various embodiments disclosed herein, the splice trays may include stackable loose tube fiber splice chips, as discussed below in relation to  FIGS.  8 A to  8 C .  FIG.  7    is a perspective view of the terminal  120  of  FIG.  2 A , further showing a splice chip  180  in the interior compartment  162 . 
       FIG.  8 A  is a top view of one embodiment of a splice chip  180 ,  FIG.  8 B  is a perspective view of the splice chip  180 , and  FIG.  8 C  is a cross-sectional side view of the splice chip  180 . Referring now to  FIGS.  8 A to  8 C , the splice chip  180  includes a plurality of central posts  182  spaced apart from each other. For example, the central posts  182  may be spaced apart equidistantly from each other, forming a plurality of slots  184 , each slot located between a pair of posts. As shown in  FIGS.  8 B and  8 C , the plurality of posts  182  may be arranged vertically along an elongated base  186 . 
     Each post  182  has a plurality of protrusions emanating therefrom, on either side of the base  186 . The protrusions may comprise lower protrusions  188  that emanate from a lower portion of the posts  182 , and upper protrusions  190  that emanate from upper portions of the posts  182 , as shown for example in  FIG.  8 C . Thus, the lower protrusions  188  and the upper protrusions  190  divide each slot  184  into two stacked slots comprising a lower slot  192  and an upper slot  194 . The lower protrusions  188  and the upper protrusions  190  may be angled relative to each other as shown for example in  FIGS.  8 A and  8 B , and may form stacked elongated slots  192  and  194  for storing loose tube fiber splices. All the lower protrusions  188   a  on a first side (side a) of the base  186  may be oriented substantially parallel to each other, and all the upper protrusions  190   a  on the first side of the base may be oriented substantially parallel to each other. Further, all the lower protrusions  188   b  on a second side (side b) of the base  186  may be oriented substantially parallel to each other, and all the upper protrusions  190   b  on the second side of the base may be oriented substantially parallel to each other. In one embodiment, the lower protrusions  188   a  on one side of the base  186  may be oriented substantially parallel to the upper protrusions  190   b  on the other side of the base. Similarly, the upper protrusions  190   a  on one side of the base  186  may be oriented substantially parallel to the lower protrusions  188   b  on the other side of the base, so as to form an “X” pattern of protrusions  188  and  190  emanating from a plurality of posts  182 . 
     As shown in  FIGS.  8 A to  8 C , the splice chip  180  has six elongated upper slots  194 . The splice chip  180  also has six elongated lower slots  192 . Each of the lower slots  192  is located under a corresponding upper slot  194 . Thus, each splice chip  180  holds 12 loose tube fiber splices: six splices stacked on top of six splices. 
     In various embodiments disclosed herein, a splice tray may be configured to receive one or more splice chips  180 . A splice tray may include a plurality of slots, each slot being configured to receive a respective splice chip  180 . For example, a slot may be configured to couple to at least portion of the base  186  of a splice chip  180 . Other embodiments of splice trays and splice chips may comprise a different mechanism for coupling. 
       FIG.  9    is a close-up view of a splice chip  180 , showing splices  200  and  202  stored in the top and bottom rows or slots of the splice chip, respectively. Thus, the splice chip  180  accommodates stacked loose tube fiber splices  200  and  202 , up to a maximum of 12 splices. 
     Some embodiments of the terminals disclosed herein may comprise fiber management modules or cassettes. Various embodiments of fiber management cassettes may comprise stackable loose tube fiber splice chips such as the splice chip  180  illustrated in  FIGS.  8 A to  8 C .  FIG.  10 A  is an exploded perspective view of one embodiment of an optical fiber cassette  206  having a loose tube fiber splice chip  180 . The cassette  206  comprises a base  208  having mounting tabs  210 . The cassette  206  further comprises a splice tray  212  and a splice tray cover  214  configured to couple to the splice tray. The splice tray is configured to receive at least one splice chip  180 . The base  208  comprises a slack storage area and is configured to couple to a slack storage cover  216 . The cassette  206  further comprises an adapter plate  218  and a top cover  220  configured to couple to the base  208 .  FIG.  10 B  is a perspective view of the assembled optical fiber cassette  206 , showing the adapter plate  218  positioned at the front of the cassette and the top cover  220  positioned at the top of the cassette. 
       FIG.  11 A  is a top view of the splice tray  212  of the optical fiber cassette  206 . The splice tray  212  includes a single splice chip  180 . The splice tray  212  may also accommodate two splice chips  180 , as shown for example in  FIG.  11 B . Other embodiments of splice trays and cassettes may accommodate a different number or arrangement of splice chips. The splice tray further comprises a fiber routing and management area. 
       FIG.  12 A  is a side view of a portion of the splice tray  212  configured for receiving a splice chip  180 . The splice chip  180  includes a plurality of chip ends  222  at the edges of the base  186  of the splice chip. The splice tray  212  includes a plurality of undercuts  224  configured to receive the plurality of chip ends  222  so as to couple the splice chip  180  to the splice tray. The chip ends  222  may be bent down as shown by the arrows and may be inserted below the undercuts  224  in the splice tray  212 .  FIG.  12 B  shows the splice chip  180  inserted into the splice tray  212 , with the chip ends  222  positioned below the undercuts  224  of the splice tray. In other embodiments, different mechanisms may be used to couple the splice chips to the splice tray. 
     Embodiments of terminals disclosed herein, such as terminal  120 , may be used in optical fiber distribution systems. For example, an incoming cable port of terminal  120  may be configured to receive an incoming cable having a plurality of fibers into the terminal. The terminal may be configured to allow connecting the fibers to a cassette, module or adapters within the terminal. Drop cables may be supplied to user locations through one or more distribution ports. Various user locations may be equipped with tap boxes configured to receive one or more fibers and to connect them to the user locations. 
     Various embodiments of terminals disclosed herein provide flexible and hardened terminals. Various embodiments of terminals disclosed herein are environmentally sealed terminals, thereby providing maximum reliability and durability in the harshest OSP environments. 
     This disclosure is not limited to the particular systems, devices and methods described, as these may vary. The terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope. 
     In the above detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be used, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the Figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein. 
     The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods, reagents, compounds, compositions or biological systems, which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. 
     As used in this document, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. Nothing in this disclosure is to be construed as an admission that the embodiments described in this disclosure are not entitled to antedate such disclosure by virtue of prior invention. As used in this document, the term “comprising” means “including, but not limited to.” 
     While various compositions, methods, and devices are described in terms of “comprising” various components or steps (interpreted as meaning “including, but not limited to”), the compositions, methods, and devices can also “consist essentially of” or “consist of” the various components and steps, and such terminology should be interpreted as defining essentially closed-member groups. 
     With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity. 
     It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.” 
     In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group. 
     As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as “up to,” “at least,” and the like include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth. 
     Various of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art, each of which is also intended to be encompassed by the disclosed embodiments.