Coaxial cables are a known type of electrical cable that may be used to carry radio frequency (“RF”) signals. Coaxial cables are widely used as transmission lines in cable television networks. FIG. 1 is a schematic perspective view of a conventional coaxial cable 10 that has been partially cut apart to reveal its internal structure. As shown in FIG. 1, the coaxial cable 10 has a central conductor 12 that is surrounded by a dielectric spacer 14. A tape 16 may be bonded to the outside surface of the dielectric spacer 14. A metallic electrical shield 18, which typically comprises braided shielding wires and, optionally, one or more electrical shielding tapes (not shown in FIG. 1), surrounds the central conductor 12, dielectric spacer 14 and tape 16. The electrical shield 18 serves as an outer conductor of the coaxial cable 10. Finally, a cable jacket 20 surrounds the electrical shield 18 to complete the coaxial cable 10.
Fiber optic cables are also well known in the art. Fiber optic cables typically include one or more optical fibers, one or more strength members such as, for example, aramid fibers or other strength yarns, and a protective outer jacket. FIG. 2 is a cross-sectional view of a conventional fiber optic cable 32. As shown in FIG. 2, the fiber optic cable 32 includes a glass (silica) core 34, a glass cladding 36, and a protective coating 38 that is typically a polymer layer such as an acrylic or other plastic layer that is integral with the core 34 and cladding 36. A jacket 40 surrounds and protects the optical fiber 32. While not shown in FIG. 2, it will be appreciated that additional components are routinely included in fiber optic cables such as strength yarns, buffer tubes additional optical fibers, etc. A wide variety of fiber optic communications cables are known in the art, including ribbon cables, loose tube cables, cables that include a single optical fiber, cables that include multiple optical fibers, etc.
Cable television networks refer to communications networks that are used to transmit cable television signals and signals relating to other services such as broadband Internet and/or Voice-over-Internet Protocol (“VoIP”) telephone service between a service provider and a plurality of subscribers. Typically, the service provider is a cable television company that may have exclusive rights to offer cable television services in a particular geographic area. The subscribers in a cable television network may include, for example, individual homes, apartments, hotels, businesses, schools, government facilities and various other entities.
Most conventional cable television networks comprise hybrid fiber-coaxial networks. In these networks, fiber optic cables are typically used to carry signals from the headend facilities of the service provider to various distribution points. These fiber optic cables may support very high bandwidth communications, and thus may provide an efficient mechanism for distributing signals throughout a service area. However, fiber optic cabling and the related equipment that are used to transmit optical signals can be substantially more expensive than coaxial cable and the related equipment that is used to transmit electrical RF signals throughout a cable television network. Consequently, less expensive coaxial cable is typically used at least in the so-called “drop” sections of a cable television network in order to carry the signals into neighborhoods and/or into individual homes, apartment complexes, businesses and other subscriber premises. Electronic interface units are located throughout the cable television networks that are used convert the optical signals into electrical signals and vice versa.
USPTO Backgrounds
USPTO Backgrounds