All the facilities and equipment used to provide telecommunications services.
Note: Plant is usually characterized as outside plant or inside plant. Outside plant, for example, includes all poles, repeaters and unoccupied buildings housing them, ducts, and cables--including the "inside" portion of interfacility cables outward from the main distributing frame (MDF) in a central office or switching center. Inside plant includes… (Read More →)

An optical fiber that has a silica-based core and a plastic cladding.
Note 1: The cladding of a PCS fiber should not be confused with the polymer overcoat of a conventional all-glass fiber.
Note 2: PCS fibers in general have significantly lower performance characteristics, i.e., higher transmission losses and lower bandwidths, than all-glass fibers. Synonym polymer-clad silica fiber.

The modulation produced by introduction of the modulating wave into the plate circuit of any tube in which the carrier frequency wave is present. [47 CFR
7
3. 14]

1. The type of computer on which a given operating system or application runs. Synonym hardware platform.
2. The operating system in use on a given computer. Synonym operating system platform.
3. The application program in use on a given computer and operating system. Synonym application platform.
Note 1: The term platform, usually with some kind of accompanying qualifying verbiage,… (Read More →)

A profile whose focus is on functionality and interfaces for a particular type of platform (e.g., workstation, personal computer, time sharing, symmetric multiprocessing) [POSIX.0].

Power Line Communications

In a building, an enclosure, created by building components such as a suspended ceiling or false floor, and used for the movement of environmental air.
Note 1: A plenum may be used to contain communications and power cables, e.g., to reach equipment installed in open office or laboratory space.
Note 2: Cables installed in plenums must meet applicable environmental and… (Read More →)

That relationship between two signals such that their corresponding significant instants occur at nominally the same rate, any variations being constrained within a specified limit.
Note: There is no limit to the phase difference that can accumulate between corresponding significant instants over a long period of time. [T
1. X1] [T1.101-1999]

PDH refers to the DS1/DS2/DS3 family of signals which were developed as an asynchronously multiplexed hierarchy for transmission systems which are now more frequently encountered as payload in a SONET system. [T
1. X1]

Phase Locked Loop