Optical networks are becoming prevalent in part because service providers want to deliver high bandwidth communication capabilities to customers. An example network may include one or more central offices that connects a number of end subscribers (also called end users) in a network. The central offices may additionally connect to a larger network such as the Internet and/or to a public switched telephone network (PSTN). The network may also include fiber distribution hubs (FDHs) having one or more optical splitters that generate a number of individual fibers that may lead to the premises of an end user.
Improvements are desired.
The present disclosure relates generally to a distribution cable defining one or more intermediate break-out locations at which various optical fibers of the distribution cable can be accessed.
In accordance with some aspects of the disclosure, a distribution cable arrangement includes optical fibers extending along a length; a jacket defining an access region to provide access to at least one of the optical fibers; and a closure disposed around the jacket to cover the access region. At least one of the optical fibers is cut to provide a first cut end and a second cut end. Both cut ends are routed out of the jacket through the access region. The first cut end is terminated at a first optical connector and the second cut end is terminated at a second optical connector. The first and second optical connectors are positioned relative to the closure to be mateable to optical cables that are external of the closure.
In some examples, the first and second optical connectors are disposed within the closure. For example, the first and second optical connectors can be received at internal ports of ruggedized optical adapters carried by the closure. In certain implementations, the closure includes a clam-shell configuration.
In other examples, the first and second optical connectors are disposed external of the closure. For example, the first and second optical connectors can be ruggedized. In certain implementations, the closure includes a heat-recoverable closure.
In some implementations, the first and second cut ends are directly terminated by the first and second optical connectors, respectively. In other implementations, the first and second cut ends are spliced to tether cables that are directly terminated by the first and second optical connectors, respectively.
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 forgoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based.
The accompanying drawings, which are incorporated in and constitute a part of the description, illustrate several aspects of the present disclosure. A brief description of the drawings is as follows:
Reference will now be made in detail to exemplary aspects of the present disclosure that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
The present disclosure relates generally to a distribution cable defining one or more intermediate break-out locations at which various optical fibers of the distribution cable can be accessed.
The jacket (i.e., overjacket) 103 of the cable 100 defines one or more access regions 109 located at various intermediate positions along the length of the cable 100. A portion of the jacket 103 is removed at each access region 109 to provide access to the optical fibers 105 or cables 104. In some examples, a window can be cut through the circumferential wall of the jacket 103 to provide access to the optical fibers 105 or cables 104 within the jacket 103. In other examples, the jacket 103 can be partially or fully removed from an axial segment of the cable 100. In certain examples, a portion of a buffer tube 104 also is removed at the access region 109 to provide access to the optical fibers 105 or cables 104 within the buffer tube 104.
At least one optical fiber 105′ of the optical fibers 105 is cut at or near the access region 109 to form a first cut end 106 and a second cut end 107. In certain examples, at least a first optical cable 104′ of the optical cables 104 is cut to form the first cut end 106 and the second cut end 107. At least the first cut end 106 is routed out of the jacket 103 at the access region 109. The first cut end 106 is terminated by a first optical connector 110. In an example, a single-fiber connector 110 (e.g., an LC connector, an SC connector, a DLX connector, and LX.5 connector, etc.) is terminated to the first cut end 106 of the optical fiber 105′. In another example, a multi-fiber connector 110 (e.g., an MPO connector, and HMFOC connector, etc.) is terminated to the first cut end 106 of the optical cable 104′. For ease of description, the remainder of this disclosure will refer to cutting an optical cable 104′ to produce the first and second cut ends 106, 107. It will be understood, however, that one or more optical fibers 105 can be utilized in place of the cables 104.
As the term is used herein, “terminated” refers to optically coupling the first cut end 106 to an optical connector 110 either directly or indirectly. In some examples, the first cut end 106 can be directly terminated to the optical connector 110. In such examples, the optical connector 110 is mounted directly to the first cut end 106 (e.g., see
In certain implementations, a plurality of the separate cables 104 can be cut at the access region 109. In such implementations, the cut ends of the optical cables 104 are routed out of the jacket 103. In some implementations, each cut end can be terminated by a separate optical connector 110. In other implementations, one or more of the cut ends can be left unterminated.
A closure mounts over the cable 100 at the access region 109. The closure is configured to cover the access region 109 of the cable 100. The first optical connector 110 is positioned relative to the closure to be mateable to an optical cable that is external of the closure. In an example, the first optical connector 110 is plugged into an internal port of an optical adapter carried by the closure. In another example, the first optical connector 110 is disposed external of the closure. In examples, unterminated cut ends can be disposed within the closure.
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The cable port 125 is configured to align the optical connector 110 with an optical connector of an external cable. For example, an optical adapter 126 can be disposed at the cable port 125. As the term is used herein, an “optical adapter” is a structure configured to align at least one optical fiber of a first optical connector with at least one fiber of a second optical connector so that optical signals may be passed therebetween. The optical adapter 126 is disposed at the cable port 125 so that a first port of the optical adapter 126 (i.e., an external port) is accessible externally of the closure 120 and a second port of the optical adapter 126 (i.e., an internal port) is accessible internally of the closure 120.
In accordance with some aspects of the disclosure, the connection system between the optical adapter 126 and the optical connector 110 can be ruggedized. As the term is used herein, a connection is “ruggedized” when the optical connector and optical adapter are configured to environmentally seal together and are configured to robustly connect together. As the term is used herein, a “robust connection” refers to a connection of an optical connector to an optical adapter such that the optical connector can withstand an axial load of at least 100 pounds without pulling out of the optical adapter. In certain examples, a robust connection structure includes twist-to-lock connections. In an example, a twist-to-lock connection includes a bayonet connection. In another example, a twist-to-lock connection includes a threaded connection.
As the term is used herein, an optical adapter 126 is “ruggedized” when the optical adapter 126 environmentally seals to the closure 120 (e.g., using a gasket) and when at least one port of the optical adapter 126 is configured to provide a ruggedized connection to an optical connector received at the port. In some examples, a ruggedized port can include a seal (e.g., a gasket) disposed therein to press against an optical connector received in the port. In other examples, the ruggedized port can include a wall or other structure against which a seal on the connector may press when the connector is received at the port.
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In some implementations, the closure 120 defines multiple cable ports 125. In certain implementations, fewer than all of the cable ports 125 of the closure 120 are populated when the cable 100 is deployed in the field. In certain implementations, a ruggedized plug 129 is received at any unpopulated cable ports 125. In the example shown in
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In certain examples, the opposite ends 101, 102 of the distribution cable 100 can be optically coupled to one or more central offices from which optical signals are provided to the optical network. For example, the cut optical cables 104′ can carry a first optical signal from a central office at the first end 101 of the cable 100 to the first cut end 106 and the cut optical cable 104′ can carry a second optical signal from a central office at the second end 102 of the cable 100 to the second cut end 107. In an example, each end 101, 102 of the cable 100 connects to a different central office. In another example, the ends 101, 102 of the cable 100 connect to the same central office. The cut ends 106, 107 of the optical cables 104′ can be optically coupled to cables leading to subscribers or other distribution points in the network. Accordingly, the optical signals can be provided to the subscribers from the central office(s) at either end of the distribution cable 100.
A closure is formed around the access region 109 to environmentally seal the cable 100 at the access region 109 to protect the optical fibers 105/cables 104. Cables located external of the closure can be mated to the optical connectors 110, 115 terminating the first and second cut ends 106, 107. The external cables can be routed to subscribers or to other distribution points of an optical network. In some implementations, the first and second optical connectors 110, 115 are disposed within the closure. In other implementations, the first and second optical connectors 110, 115 are disposed external of the closure.
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The closure 130 also defines a routing cavity 134 into which the first cut end 106 extends out of the jacket 103. The closure 130 defines two or more cable ports 135 at which external cables (e.g., connectorized with hardened multi-fiber optical connectors) can be mated to the optical connectors 110, 115. The routing cavity 134 is sufficiently sized for routing the first and second optical connectors 110, 115 to the respective ports 135 without violating a minimum bend radius of the optical fibers 105.
In the example shown, the closure 130 defines a first cable port 135 at which an external cable can be mated to the first optical connector 110 and a second cable port 135b at which another external cable can be mated to the second optical connector 115. In some implementations, the first and second cable ports 135a, 135b are disposed at a common end (e.g., first end 136, second end 137) or side of the closure 130. In other implementations, cable ports 135 can be defined at both ends 136, 137 of the closure 130. In still other implementations, cable ports 135 can be defined at any desired portion of the closure 130.
In some implementations, a ruggedized optical adapter 126 (e.g., the ruggedized optical adapter 126 described above with reference to
Cut ends 106, 107 of one or more optical cables 104′ are routed out of the jacket 103, through the routing cavity 134, and to the internal ports of the optical adapters 126a, 126b. The first optical connector 110 is plugged into the internal port of the first optical adapter 126a and the second optical connector 115 is plugged into the internal port of the second optical adapter 126b. In the example shown in
In some implementations, the closure 130 can define cable ports 135 in addition to the first and second cable ports 135a, 135b. In certain implementations, fewer than all of the cable ports 135 of the closure 130 are populated when the cable 100 is deployed in the field. In certain implementations, a ruggedized plug 129 is received at any unpopulated cable ports 135. In the example shown in
In some implementations, each of the first and second optical connectors 110, 115 can include a watertight external seal configured to cooperate with a mating connector or mating adapter port to environmentally seal the optical fibers terminated by the first and second optical connectors 110, 115. In other implementations, each of the first and second optical connectors 110, 115 is configured to receive a mating connector or be received at a mating adapter having a watertight seal to environmentally seal the optical fibers terminated by the first and second optical connectors 110, 115. In some implementations, the first and second optical connectors 110, 115 include coupling nuts having internal threads. In other implementations, the first and second optical connectors 110, 115 include coupling nuts having external threads. In still other implementations, the first and second optical connectors 110, 115 include bayonet connection structure.
In some implementations, the first cut ends 106, 107 of the cut optical cable 104′ are directly terminated to the respective connectors 110, 115 by routing a length of each cut end 106, 107 out of the jacket 103 to extend along the cable 100 so that the optical connectors 110, 115 are directly terminated to the cut ends 106, 107 at a location spaced from the access region 109. In other implementations, the cut ends 106, 107 of the cut optical cable 104′ are terminated to the respective connectors 110, 115 by optically splicing (e.g., mechanically splicing, fusion splicing, etc.) the cut end 106, 107 to respective tether cables 114, 118 (e.g., by splicing the optical fibers 105′ at the cut ends 106, 107 to stub fibers 111, 116 of the tether cables 114, 118). The first and second tether cables 114, 118 are terminated by the first and second optical connectors 110, 115, respectively.
In some implementations, the closure 150 includes a heat recoverable closure that surrounds the cable 100 at the access region 109 and does not enclose the first and second optical connectors 110, 115. In certain implementations, the heat recoverable closure 150 also surrounds jacketed portions of the cable at opposite ends of the access region 109. In certain implementations, the heat recoverable closure 150 surrounds and protects (e.g., environmentally seals, inhibits access to, etc.) the splices between the cut ends 106, 107 and the stub fibers 111, 116.
In some implementations, the heat recoverable closure 150 includes a heat-recoverable material that is wrapped around the cable 100 at the access region 109. A clamp member (e.g., a metal clamp) can be disposed around the wrapped heat-recoverable material. In other implementations, the heat recoverable closure 150 can include a sheath threaded onto the cable 100 from one end 101, 102 of the cable 100.
Referring to the figures in general, an optical cable 100 can be manufactured with one or more of any of the above-described break-out locations at intermediate locations along a length of the cable 100. For example, one or more break-out locations can be formed on the cable 100 at a factory prior to deployment of the optical cable in the field. In other implementations, one or more break-out locations can be formed on the cable 100 in the field after deployment of the optical cable 100.
To add a break-out location to the optical cable 100, a portion of the jacket 103 is removed to provide an access region 109. At least one optical fiber 105′ of the cable 100 is accessed and cut at the access region 109. The first cut end 106 of the optical fiber(s) 105′ is terminated by the first optical connector 110. The second cut end 107 of the optical fiber(s) 105′ is terminated by the second optical connector 115. A closure 120, 130, 150 is disposed at the access region 109 of the cable 100.
In certain implementations, a first housing piece 121, 131 is positioned partially around the jacket 103 at the access region 109. A second housing piece 122, 132 is positioned partially around the jacket 103 so that the first and second housing pieces 121, 122, 131, 132 cooperate to form the closure 120, 130 that surrounds the jacket 103 and covers the access region 109. In examples, the first and second optical connectors 110, 115 are routed towards a common end of the closure 120, 130.
In some examples, the first optical connector 110 is plugged into an interior port of a first ruggedized optical adapter 126 carried by the closure 120, 130. In certain examples, the second optical connector 115 is plugged into an interior port of a second ruggedized optical adapter 126 carried by the closure 130. In other examples, a heat recoverable closure 150 is disposed around the access region 109 and not around the optical connectors 110, 115; and heat is applied to the heat recoverable closure 150 to shrink the heat recoverable closure 150 over the access region 109.
The above specification, examples and data provide a complete description of the manufacture and use of the structure of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
This application claims the benefit of U.S. Provisional Application No. 62/057,786, filed Sep. 30, 2014, and titled “Distribution Cable with Bidirectional Breakout Locations,” the disclosure of which is hereby incorporated herein by reference.
Number | Date | Country | |
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62057786 | Sep 2014 | US |