Telecommunications terms starting with P

636 terms

PBX trunk See trunk.
PC Personal computer.
PCB Printed Circuit Board.
PCM (1) Pulse Code Modulation.
PCM multiplex equipment See multiplexer.
PCS (1) Permanent Change of Station (ILS term). (2) Planning and Control System.
PCS application From a user-identity-module (UIM) perspective, the files, commands and data used to support PCS services. [T1.707-1998]
PCS number A number that uniquely identifies a PCS user and is used to place or forward a call to that user. [T1.244-1995] Synonyms personal number, UPT number.
PCS session That part of the card session dedicated to the PCS operation. [T1.707-1998]
PCS switching center In personal communications service, a facility that (a) supports access-independent call control/service control, and connection control (switching)…
PCS System In personal communications service, a collection of facilities that provides some combination of personal mobility, terminal mobility, and service profile…
PDH Acronym for plesiochronous digital hierarchy. PDH refers to the DS1/DS2/DS3 family of signals which were developed as an asynchronously multiplexed…
PDM Program Decision Memorandum (DD 5000 term).
PDN Abbreviation for public data network.
PDS Particularly Dangerous Situation (PDS) wording is used in rare situations when long-lived, strong and violent tornadoes are possible.
PDU Abbreviation for protocol data unit.
PE Program Element.
peak busy hour Synonym busy hour.
peak emission wavelength Of an optical emitter, the spectral line having the greatest power. Synonym peak wavelength.
peak envelope power (of a radio transmitter) [PEP, pX, PX] The average power supplied to the antenna transmission line by a transmitter during one radio frequency cycle at the crest of the modulation envelope…
peak limiting A process by which the absolute instantaneous value of a signal parameter is prevented from exceeding a specified value.
peak power output The output power averaged over that cycle of an electromagnetic wave having the maximum peak value that can occur during transmission.
peak signal level In a transmission path, the maximum instantaneous signal power, voltage, or current at any point. 2.
peak spectral emission See peak emission wavelength.
peak wavelength Synonym peak emission wavelength. 2. Of an optical bandpass filter, the wavelength that suffers the lowest loss. [After FAA]
peak-to-average ratio (p/a r) The ratio of the instantaneous peak value, i.e., maximum magnitude, of a signal parameter to its time-averaged value.
peak-to-peak value The absolute value of the difference between the maximum and the minimum magnitudes of a varying quantity.
pedestal 1.Black level expressed as an offset in voltage or IRE units relative to blanking level. Conventionally, approximately 54 mV (7.
peer entity In layered systems, entities in the same layer but in different systems (nodes) that must exchange information to achieve a common objective. [After T1.
peer group In Open Systems Interconnection (OSI)--Architecture, a group of functional units in a given layer of a network in which all the functions performed by the…
peer protocol A formal language used by peer entities to exchange user data. [TI.110-1987].
peer-entity authentication 1. The corroboration that a peer entity in an association is the one claimed. [T1.233-1993] 2.
peg count 1. In communication systems, a count that is made of the number of times that an event or condition occurs. [From Weik '89] 2.
pel In a facsimile system, the smallest discrete scanning line sample containing only monochrome information, i.e., not containing gray-scale information.
penetration The intentional passage, through a building wall or partition, or an equipment enclosure or chassis, of a signal-bearing communications medium, e.g.
penetration test A test of a system which attempts to breach the System Security policy. Also known as "pen-test" [CESG].
Penetration Testing The portion of security testing in which the penetrators attempt to circumvent the security features of the system.
PEP Producibility Engineering and Planning.
per-call key [A] unique traffic encryption key generated automatically by certain secure telecommunications systems to secure single voice or data transmissions.
percent break In pulsed telephone signaling (dialing), the ratio, expressed in percent, of (a) the open-circuit (break) time to (b) the sum of the open- and…
percentage modulation In angle modulation, the fraction of a specified reference modulation, expressed in percent. 2.
perfect forward secrecy In cryptography, of a key-establishment protocol, the condition in which the compromise of a session key or long-term private key after a given session…
Performance Those operational and support characteristics of the system that allow it to effectively and efficiently perform its assigned mission over time.
performance anomalies A discrepancy between actual and desired characteristics of an item. An anomaly may or may not affect the ability of an item to perform a required…
performance evaluation The technical assessment of a system or system component to determine how effectively operating objectives have been achieved [POSIX.0].
performance management In network management, (a) a set of functions that evaluate and report the behavior of telecommunications equipment and the effectiveness of the network…
performance measurement period The period during which performance parameters are measured. Note: A performance measurement period is determined by required confidence limits and may…
performance parameter A quality, usually quantified by a numerical value, which quality characterizes a particular aspect, capability, or attribute of a system.
performance primitives Basic error events or other performance-related occurrences that may be detected by monitoring a digital signal. [T1.503-1996]
performance reliability The ability of an item to perform a required function under given conditions for a given time period.
Performance Requirement A requirement that specifies a performance characteristic that a system or system or system component must possess; for example, speed, accuracy…
performance standard A statement of general criteria that define a desired result without specifying the techniques for achieving that result.
periapsis In a satellite orbit, the point that is closest to the gravitational center of the system consisting of the primary body and the satellite.
Perigee The closest distance between moon and earth or the earth and sun.
perigee altitude See altitude of the apogee or of the perigee.
perimeter network An Internet Protocol (IP) network segment that contains resources, such as Web servers and virtual private network (VPN) servers, that are available to…
period (of a satellite) The time elapsing between two consecutive passages of a satellite through a characteristic point on its orbit. [NTIA] [RR]
periodic antenna An antenna that has an approximately constant input impedance over a narrow range of frequencies.
periods processing Processing of various levels of classified and unclassified information at distinctly different times.
peripheral device A hardware device not part of the central computer (e.g., digitizers, plotters, and printers).
peripheral equipment In a data processing system, any equipment, distinct from the central processing unit, that may provide the system with additional capabilities.
peripheral node Synonym endpoint node.
periscope antenna An antenna configuration in which the transmitting antenna is oriented to produce a vertical radiation pattern, and a flat or off-axis parabolic…
permanent bond A bond not expected to require disassembly for operational or maintenance purposes.
permanent signal (PS) An extended off-hook condition not followed by dialing. 2. A connect signal from the network that has not been followed by network outpulsing within a…
permanent storage A storage device in which stored data are nonerasable.
permanent virtual circuit (PVC) A network connection with a static route defined in advance, usually by manual setup.
permissible interference Observed or predicted interference which complies with quantitative interference and sharing criteria contained in these [Radio] Regulations or in CCIR…
permuter [A] device used in crypto-equipment to change the order in which the contents of a shift register are used in various nonlinear combining circuits.
Persistent Chemicals with a long inactivation or degradation time, such as some pesticides.
persistent data Information that endures beyond a single instance of use, e.g., longer than one call attempt. [T1.667-1999]
personal agent Synonym droid. See bot.
personal authenticating information (PAI) Information such as a secret password, a badge, or biometric data-or any combination of these-used to authenticate a user's identity. [After X9.26]
Personal Communications Service See PCS.
Personal Communications Service (PCS) Any of several types of wireless, voice and/or data communications systems, typically incorporating digital technology.
personal de-registration The process by which end users cancel a previous registration to a terminal. [T1.702-1995] [T1.Rpt34-1994]
personal identification device (PID) A physical device possessed by a user for authentication purposes [CESG].
personal identification number A unique and secret identification code similar to a password that is assigned to an authorized user and used to gain access to personal information or…
personal mobility In universal personal telecommunications (UPT), (a) the ability of a user to access telecommunication services at any UPT terminal on the basis of a…
personal mobility controller In UPT (universal personal telecommunications), a facility that provides the control logic for user authentication, service request validation, location…
personal mobility management In PCS (personal communication service), the capability that (a) provides authentication of user identification and maintains user location information in…
personal number A number that uniquely identifies a PCS or UPT user (universal personal telecommunications service user) and is used to place, or forward, a call to that…
personal registration In universal personal telecommunications, the process of associating a UPT user with a specific terminal.
personal station A light-weight, pocket-sized FPLMTS terminal (Future Public Land Mobile Telecommunication Systems terminal). [CCITT (ITU-T) Rec. F.115]
personal terminal In personal communications service, a lightweight, small, portable terminal that provides the capability for the user to be either stationary or in motion…
PGP Abbreviation for pretty good privacy. A publicly available implementation of a public-key encryption system using no trusted third party.
phantom circuit A third circuit derived from two suitably arranged pairs of wires, called side circuits, with each pair of wires being a circuit in itself and at the same…
phantom facility A transmission facility derived with repeating coils from two or more pairs of wires. [T1.238-1994/97] Synonyms phantom circuit, phantom pair.
phantom group Three circuits that are derived from simplexing two physical circuits to form a phantom circuit.
phantom pair Synonyms [loosely] phantom circuit, phantom facility.
Phase Alternating current is carried by conductors and a ground to residential, commercial, or industrial consumers.
phase angle Of a periodic wave, the number of suitable units of angular measure between a point on the wave and a reference point.
phase bandwidth Of a network or device, the width of the continuous frequency range over which the phase-vs.
phase coherence The state in which two signals maintain a fixed phase relationship with each other or with a third signal that can serve as a reference for each.
phase coherent See phase coherence.
phase constant The imaginary part of the axial propagation constant for a particular mode, usually expressed in radians per unit length.
phase delay In the transmission of a single-frequency wave from one point to another, the delay of an arbitrary point in the wave that identifies its phase.
phase departure A phase deviation from a specified value. 2. An unintentional deviation from the nominal phase value.
phase detector A circuit or instrument that detects the difference in phase between corresponding points on two signals.
phase deviation In phase modulation, the maximum difference between the instantaneous phase angle of the modulated wave and the phase angle of the unmodulated carrier.