Passive optical networks are becoming prevalent in part because service providers want to deliver high bandwidth communication capabilities to customers. Passive optical networks are a desirable choice for delivering high speed communication data because they may not employ active electronic devices, such as amplifiers and repeaters, between a central office and a subscriber termination. The absence of active electronic devices may decrease network complexity and/or cost and may increase network reliability.
FIG. 1 illustrates a network 100 deploying passive fiber optic lines. As shown in FIG. 1, the network 100 may include a central office 110 that connects a number of end subscribers 115 (also called end users 115 herein) in a network. The central office 110 may additionally connect to a larger network such as the Internet (not shown) and a public switched telephone network (PSTN). The network 100 may also include fiber distribution hubs (FDHs) 130 having one or more optical splitters (e.g., 1-to-8 splitters, 1-to-16 splitters, or 1-to-32 splitters) that generate a number of individual fibers that may lead to the premises of an end user 115. The various lines of the network can be aerial or housed within underground conduits (e.g., see conduit 105).
The portion of network 100 that is closest to central office 110 is generally referred to as the F1 region, where F1 is the “feeder fiber” from the central office. The F1 portion of the network may include a distribution cable having on the order of 12 to 48 fibers; however, alternative implementations may include fewer or more fibers. The portion of network 100 that includes an FDH 130 and a number of end users 115 may be referred to as an F2 portion of network 100. Splitters used in an FDH 130 may accept a feeder cable having a number of fibers and may split those incoming fibers into, for example, 216 to 432 individual distribution fibers that may be associated with a like number of end user locations.
Referring to FIG. 1, the network 100 includes a plurality of breakout locations 125 at which branch cables are separated out from main cable lines. Breakout locations can also be referred to as tap locations, drop cable locations, splice locations or branch locations. Branch cables can also be referred to as drop cables, drop lines, breakout cables or stub cables. Branch cables are often connected to drop terminals 104 that include connector interfaces for facilitating coupling the fibers of the branch cables to a plurality of different subscriber locations. Breakout locations are often enclosed by a field mounted enclosure which protects optical splices (e.g., fusion or mechanical splices) or other types of optical couplings (e.g., connectorized optical couplings) provided at the breakout location. Since breakout locations are often provided at mid-span locations on the main cable being accessed, it is desirable for field mounted enclosures to be readily mountable at mid-span access locations without requiring the main cable to be “threaded” lengthwise through the enclosure.
Fiber optic networks can extend to multi-dwelling units such as apartment buildings and condominiums. FIG. 2 shows a fiber optic network including a cable 150 routed into a multi-dwelling unit 152. Within the multi-dwelling unit 152, branch cables/fibers are optically coupled to the fibers of the cable 150 at optical coupling locations (e.g., fusion splices, mechanical splices or connectorized optical couplings). The optical coupling locations can be enclosed within one or more wall boxes that are typically equipped with doors/covers that can be opened to provide easy access to the optical coupling locations. The wall boxes are typically provided at different floors of the multi-dwelling unit with each wall box having optical coupling locations corresponding to a plurality of different subscribers (e.g., each resident on a given floor).