Telecommunications terms starting with P

636 terms

p × 64 In video teleconferencing, pertaining to a family of CCITT (now, ITU-T) Recommendations, where p is a non-zero positive integer indicating the number of…
PABX Abbreviation for private automatic branch exchange. See PBX. Note: Use of the term "PBX" is more common than "PABX," regardless of automation.
Packet A unit of data sent across a network which may contain identify and routing information.
packet assembler/disassembler (PAD) A functional unit that enables data terminal equipment (DTE) not equipped for packet switching to access a packet-switched network.
packet entry event A packet layer reference event that corresponds to a packet entering a network section (from a circuit section) or a packet entering a DTE (from an access…
packet exit event A packet layer reference event that corresponds to a packet exiting a network section (to a circuit section) or a packet exiting a DTE (to an access…
packet filter A type of firewall in which each packet is examined and either allowed to pass through or is rejected, based on local security policy. [INFOSEC-99]
packet filtering The action a device takes to selectively control the flow of data to and from a network.
packet format The structure of data, address, and control information in a packet. Note: The size and content of the various fields in a packet are defined by a set of…
packet header A header consisting of octets 4 to 8 (inclusive) of the frame (flags excluded from the octet numbers). [After T1.509-1995]
packet Internet groper See ping.
packet layer reference event The event that occurs when a packet crossing a section boundary changes the state of the packet layer interface. [T1.504-1989]
packet mode A mode of operating a communications network in which packet switching is used rather than message switching. [From Weik '89]
Packet Sniffer Software that observes and records network traffic.
packet stream A collection of logical links multiplexed together onto one physical channel between two endpoints of the wideband packet network. [T1.509-1995]
packet switching The process of routing and transferring data by means of addressed packets so that a channel is occupied during the transmission of the packet only, and…
packet transfer mode A method of information transfer, by means of packet transmission and packet switching, that permits dynamic sharing of network resources among many…
packet-mode terminal Data terminal equipment (DTE) that can control, format, transmit, and receive packets.
packet-switched data transmission service A service that (a) provides for the transmission of data in the form of packets, (b) switches data at the packet level, and (c) may provide for the…
packet-switching network A switched network that transmits data in the form of packets.
packet-switching node In a packet-switching network, a node that contains data switches and equipment for controlling, formatting, transmitting, routing, and receiving data…
packetization interval Defines the duration of the sampled speech of the access channel that has been collected, coded, and packetized.
PAD Short for "scratchpad".
padding In cryptography, a bit or a string of bits appended to a message either for filtering purposes or to cause the message to contain an even multiple of the…
padlocking The use of special techniques to protect data or software against unauthorized copying. [2382-pt.8]
pager A small radio receiver designed to be carried by a person and to give an aural, visual, or tactile indication when activated by the reception of a radio…
paging A one-way communications service from a base station to mobile or fixed receivers that provide signaling or information transfer by such means as tone…
paging and radiotelephone service See PARS.
paging receiver See pager.
paging system A one-way mobile radio service where a user carries a small, lightweight miniature radio receiver capable of responding to coded signals.
pair-gain system A transmission system that uses concentrators or multiplexers so that fewer wire pairs may be used than would otherwise be required to provide service to…
paired cable A cable made up of one or more separately insulated twisted-wire pairs, none of which is arranged with another to form quads.
paired disparity code A code in which some or all of the characters are represented by two sets of digits of opposite disparity that are used in sequence so as to minimize the…
PAL Permissive Action Link.
PAL-M A modified version of the phase-alternation-by-line (PAL) television signal standard (525 lines, 50 Hz, 220 V primary power), used in Brazil.
palm computer See palm-top.
palm-top A small (pocket-size), hand-held computer, often including network-access software, personal-schedule software, and a basic word processor.
PAM Pulse Amplitude Modulation.
PAMA Abbreviation for pulse-address multiple access.
Panning An applied material, usually metal, that covers the front (exterior) surface of an existing window frame or mullion
par meter Abbreviation for peak-to-average ratio meter. A meter used to measure, calculate, and display the ratio of the peak power level to the time-averaged power…
parabolic antenna An antenna consisting of a parabolic reflector and a radiating or receiving element at or near its focus.
parabolic profile In an optical fiber, a power-law index profile with the profile parameter, g, equal to 2. Synonym quadratic profile.
parallel computer A computer that has multiple arithmetic units or logic units that are used to accomplish parallel operations or parallel processing.
parallel port A port through which two or more data bits are passed simultaneously, such as all the bits of an 8-bit byte, and that requires as many input channels as…
Parallel Processing In parallel processing multiple processors (CPUs) divide up a large task into smaller ones and each CPU acts on the subdivided task simultaneously so that…
parallel transmission The simultaneous transmission of the signal elements of a character or other data item. 2.
parallel-to-serial conversion Conversion of a stream of multiple data elements, received simultaneously, into a stream of data elements transmitted in time sequence, i.e.
parametric amplifier (paramp) An amplifier that (a) has a very low noise level, (b) has a main oscillator that is tuned to the received frequency, (c) has another pumping oscillator of…
parasitic element Of an antenna, a directive element that is not connected to a radio transmitter or receiver either directly or via a feeder, but is coupled to the driven…
parasitic emission In a communications system in which one or more electromagnetic sources are used, electromagnetic radiation--such as lightwaves, radio waves, microwaves…
paraxial ray In optical systems, a ray that is close to and nearly parallel with the optical axis.
Parity A form of data protection used by RAID level 5 to recreate the data of a failed drive in a disk array.
parity bit An extra bit that can be added to a group of "0" bits and "1" bits to make the parity of the group odd or even.
parity check A test that determines whether the number of ones or zeros in an array of binary digits is odd or even.
parking party Representative of the served user who parks a call via "call park."
PARS Abbreviation for paging and radiotelephone service. A radio service in which common carriers are authorized to offer and provide paging and radiotelephone…
part 68 The section of Title 47 of the Code of Federal Regulations governing (a) the direct connection of telecommunications equipment and customer premises…
partial-dial condition A condition in which outpulsing has commenced, insufficient information has been received by the customer installation (CI) to process the call and no…
partitioned security mode [An] information-system (IS) security mode of operation wherein all personnel have the clearance, but not necessarily formal access approval and…
party ID 1. The served user's (or controller's) reference to a particular party within the context of a call.
party line In telephone systems, an arrangement in which two or more user end instruments, usually telephones, are connected to the same loop.
passband The portion of spectrum, between limiting frequencies (or, in the optical regime, limiting wavelengths), that is transmitted with minimum relative loss or…
passive device A device that does not require a source of energy for its operation. Note: Examples of passive devices are electrical resistors, electrical capacitors…
passive element Synonym parasitic element.
passive satellite In a satellite communications system, a satellite that only reflects signals from one Earth station to another, or from several Earth stations to several…
Passive Sensor A sensor that detects naturally occurring emissions from a target for tracking and/or identification purposes.
passive star See star coupler.
passive station On a multipoint connection or a point-to-point connection using basic mode link control, any tributary station waiting to be polled or selected.
passive threat 1. Of a data or information processing system, a threat of disclosure of information without changing the state of the system.
passphrase [A] sequence of characters, longer than the acceptable length of a password, that is transformed by a password system into a virtual password of…
Password A secret code utilized, usually along with a user ID, in order to log on or gain access to a PC, network or other secure system, site or application.
password history With respect to a given information system (IS) asset, a log of expired passwords, used primarily for automatic comparison with proposed new passwords.
password length equation An equation that determines an appropriate password length, M, which provides an acceptable probability, P, that a password will be guessed in its…
password length parameter A basic parameter affecting the password length needed to provide a given degree of security.
patch A downloadable update that fixes bugs, improves stability and introduces new features to a program.
patch and test facility (PTF) A facility in which supporting functions, such as (a) quality control checking and testing of equipment, links, and circuits, (b) troubleshooting, (c)…
patch bay An assembly of hardware so arranged that a number of circuits, usually of the same or similar type, appear on jacks for monitoring, interconnecting, and…
patch panel One segment of a patch bay.
path The hierarchical description of where a directory, folder, or file is located on a computer or network.
path attenuation Synonym path loss.
path clearance In microwave line-of-sight communications, the perpendicular distance from the radio-beam axis to obstructions such as trees, buildings, or terrain.
path intermodulation noise See intermodulation noise.
path loss In a communication system, the attenuation undergone by an electromagnetic wave in transit between a transmitter and a receiver.
path overhead (POH) Overhead assigned to and transported with the payload until the payload is demultiplexed.
path profile A graphic representation of the physical features of a propagation path in the vertical plane containing both endpoints of the path, showing the surface…
path quality analysis In a communications path, an analysis that (a) includes the overall evaluation of the component quality measures, the individual link quality measures…
path quality matrix A data bank that contains path-quality analyses used to support path selection and routing determination.
path survey The assembling of pertinent geographical and environmental data required to design a radio communication system.
Pattern Recognition Technology that searches data for like patterns and flags, and extracts the pertinent data, usually utilizing an algorithm.
Pawsey stub A device for connecting an unbalanced coaxial feeder to a balanced antenna.
PAX Abbreviation for private automatic exchange. See PBX.
Payload The input data to the CCM generation-encryption process that is both authenticated and encrypted.
payload loopback A signal used to command the far-end receiver to loop back the received payload. [T1.107-1988]
payload module The portion of a payload that completely occupies one or more channels.
payload overhead Bits that are assigned at the source and remain with the information payload until the payload reaches the sink and are used for functions associated with…
payload pointer The pointer that indicates the location of the beginning of the synchronous payload envelope. [T1.105-1988]
PBER Abbreviation for pseudo bit-error ratio. In adaptive high-frequency (HF) radio, a bit error ratio derived by a majority decoder that processes redundant…
PBX Private Branch Exchange - a telephony term describing a private telephone network used within an enterprise.
PBX tie trunk : See tie trunk.