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There are 60 names in this directory beginning with the letter P.
PA: Power Amplifier

Power Amplifier (PA) is a device for taking a low or intermediate-level signal and significantly boosting its power level. A power amplifier is usually the final stage of amplification in a transmitter.

Packet Radio

Packet radio is a form of digital data transmission used in amateur radio to construct wireless computer networks. Its name is a reference to the use of packet switching between network nodes, which allows multiple virtual circuits to coexist on a single radio channel. Packet radio networks use the AX.25 data link layer protocol, derived from the X.25 protocol suite and designed for amateur radio use.

PACS: Personal Access Communications Sys

Personal Access Communications System (PACS) is a low mobility low power wireless system designed for residential use.


Paging refers to deliver a message to someone when their location is unknown through a wireless device usually known as a pager.

PAM: Pulse Amplitude Modulation

Pulse Amplitude Modulation (PAM) is a form of signal modulation in which the data is encoded in the amplitude of a series, or train, of regularly recurrent signal pulses. PAM is used less frequently than PCM (Pulse-Code Modulation).

PAN: Personal Area Network

A personal area network (PAN) is a computer network used for communications among computer devices (including telephones and personal digital assistants) close to one person within a few meters. PAN allows devices to work together and share information and services. Using Bluetooth wireless technology, Personal Area Networks can be created in public places, in your home, in your office, and even in your car. This network enables everyday devices to become smart, tetherless devices–working and communicating together. For example, it offers the ability to wirelessly synchronize with your desktop to access your e-mail and Internet/intranet from remote locations.

Panel Antenna

Panel Antenna is an antenna type that radiates in only a specific direction. Panel antennas are commonly used for point-to-point situations. You may also see them called “patch antennas.”

Parabolic Antenna

Parabolic Antenna is an antenna type that radiates a very narrow beam in a specific direction. Parabolic antennas offer the highest gain for long-range point-to-point situations.


Paring is the process of engaging two Bluetooth devices to each other so they can communicate.


Parity is a simple error detection scheme. The method usually involves counting the '1' bits in a codeword and then setting an additional bit to either '1' or '0' depending on whether the original number of '1' bits was even or odd.

Partial Response Signalling

Partial Response Signalling is a signalling technique in which a controlled amount of intersymbol interference is introduced at the transmitter to shape the transmitted spectrum.


Passphrase, also called password, is the words you must enter to authenticate both sides of the connection when pairing Bluetooth devices. More generically, you may see passphrase used in place of “password” to indicate that you can enter more than a single word.

Path loss

Path loss is the amount of loss introduced by the propagation environment between a transmitter and receiver. Power loss that occurs when RF waves are transmitted through the air. This loss occurs because the atmosphere provides a filtering effect to the signal. Certain electromagnetic frequencies (very high and non-commercial) are completely blocked or filtered by the atmosphere.

PCH: Paging Channel

Paging Channel (PCH), used primarily to notify the mobile that it has an incoming call, is a logical channel in GSM, cdma2000, and W-CDMA systems used to send messages to mobile station.

PCIA: Personal Communications Industry A

Personal Communications Industry Association (PCIA) is a trade group representing PCS, SMR, private radio and other wireless users and carriers.

PCM: Pulse Code Modulation

Pulse Code Modulation (PCM) is the most predominant type of digital modulation in use today. PCM performs an analog to digital conversion of the speech waveform through a sampling process and encodes and transmits the samples in a serial bit stream as 8-bit digital words.

PCN: Personal Communications Network

Personal Communications Network (PCN) is a standard for digital mobile phone transmissions operating at a frequency of 1800 MHz (also referred to as GSM 1800). It is used in Europe and Asia Pacific.

PCS: Personal Communication Service

Personal Communication Service (PCS) describes a wide variety of two-way digital wireless service offerings in North America operating at 1900 MHz. PCS services include next generation wireless phone and communication services, wireless local loop, inexpensive walk-around communications service with lightweight, low-powered handsets, in-building cordless voice services for business, in-building wireless LAN service for business, enhanced paging service as well as wireless services integrated with wired networks. A Personal Communications System refers to the hardware and software that provide communications services.

PCU: Packet Control Unit

The Packet Control Unit (PCU) is a late addition to the GSM standard. It performs some of the processing tasks of the Base Station Controller (BSC), but for packet data. The allocation of channels between voice and data is controlled by the base station, but once a channel is allocated to the PCU, the PCU takes full control over that channel. The PCU can be built into the base station, built into the BSC, or even in some proposed architectures, it can be at the SGSN site.

PDA: Personal Digital Assistant

Personal Digital Assistant (PDA) is a small, handheld wireless device for transmitting pages, data messages, faxes and e-mails. It also acts as an electronic organizer, giving you access to schedules and contact lists. The term is often used interchangeably with PIM (personal information manager). The 3Com PalmPilot is an example of a PDA or PIM.

PDC: Personal Digital Cellular

Personal Digital Cellular (PDC) is a TDMA-based 2G mobile phone standard developed and used exclusively in Japan. PDC uses 25 kHz carrier, 3 time slots, pi/4-DQPSK modulation and low bit-rate 11.2 kbit/s and 5.6 kbit/s (half-rate) voice codecs. PDC is implemented in the 800 MHz (downlink 810-888 MHz, uplink 893-958 MHz), and 1.5 GHz (downlink 1477-1501 MHz, uplink 1429-1453 MHz) bands. The air interface is defined in RCR STD-27 and the core network MAP by JJ-70.10.

PDCP: Packet Data Convergence Protocol

Packet Data Convergence Protocol (PDCP) is used in UMTS 3G network to map higher-level protocol characteristics onto the characteristics of the underlying radio-interface protocols, providing protocol transparency for higher-layer protocols. PDCP also provides protocol control information compression.

PDF: Policy Decision Function

Policy Decision Function (PDF), a component in the IP Multimedia Subsystem (IMS), controls traffic entering the packet-switched network by allocating or denying IP bearer resources.

PDF: Probability Density Function

In mathematics, a probability density function (pdf) represents a probability distribution in terms of integrals. Informally, a probability density function can be seen as a “smoothed out” version of a histogram: if one empirically measures values of a continuous random variable repeatedly and produces a histogram depicting relative frequencies of output ranges, then this histogram will resemble the random variable's probability density.

PDP Context

Packet data protocol (PDP) context is a term used in the mobile wireless network indicating a logical association between an MS (Mobile Station) and PDN (Public Data Network) running across a GPRS network. The context defines aspects such as Routing, QoS (Quality of Service), Security, Billing etc.

Peak power

Peak power is the maximum instantaneous power radiated by a pulsed or bursted transmitter. It is the power radiated while the transmitter is keyed or operated.

PER: Packed Encoding Rules

Packed Encoding Rules (PER) is a set of rules that specifies how ASN.1-defined information is encoded when transmitted, and how it is decoded when received. PER is a successor to the Basic Encoding Rules (BER). It is more efficient in terms of the number of bytes transmitted and the size of the generated encoder and decoder.

PFS: Proportional Fair Scheduling

Proportional Fair Scheduling (PFS) is a scheme for wireless communication for both a single antenna system and multiple transmit and receive antennas. The Proportional Fair algorithm is an algorithm that schedules the channel for the station that has the maximum of the priority function, where T denotes the data rate potentially achievable for the station at the present moment (in the present time slot), R is the average data rate of this station. Parameters α and β tune the fairness of the scheduler, that is, is it fair to all stations giving them equal bandwidth or is the scheduler maximizing the throughput of the channel.


Generally speaking, phase is the current position in the cycle of something that changes cyclically.

Phase jitter

Phase jitter is the amount of uncertainty introduced in digital demodulation caused by the rapid fluctuation of the frequency of the transmitted signal, typically due to imperfections in the clock recovery timing.

Phase Modulation

Phase Modulation (PM) is the scheme of modulation that the phase of the carrier signal is modulated in accordance with the message signal

PHP: Personal Handy Phone

Personal Handy Phone (PHP) is the mobile handset used with the Japanese Personal Handy Phone system.

PHS: Personal HandyPhone System

Personal HandyPhone System (PHS) was developed in Japan as a cordless telecommunication system operating within the band 1895MHz to 1918MHz. PHS is a lightweight portable wireless telephone that functions as a cordless phone at home and as a mobile phone elsewhere. The Personal Handyphone also handles voice, fax, and video signals.

Physical channel

Physical channel is the actual radio channel that carries the various logical and traffic channels in a wireless system.

Pico cell

Pico cell is a very small cell in a mobile network for boosting capacity within buildings.

Pilot code

Pilot code is a logical channel in a CDMA system characterized by an unmodulated direct sequence spread-spectrum signal continuously monitored by each base station. It allows the mobile stations to acquire the timing of the forward channel, serves as a phase reference for demodulation, and allows the mobile to search out the best (strongest) base stations for acquisition and hand-off.

Pilot pollution

Pilot pollution is a type of co-channel interference in CDMA systems caused when the pilot code from a distant cell or base station is powerful enough to create an interference problem.

PIN: Personal Identification Number

Personal Identification Number (PIN) is a code used for all GSM-based phones to establish authorization for access to certain functions or information. The PIN code is delivered together with your subscription.

PLL: Phase Locked Loop

Phase Locked Loop (PLL) is a major component in the frequency synthesizer scheme. This device provides a wide, flexible range of internal frequency dividers which allow the designer the ability to create a synthesizer to match design requirements.

PLMN: Public Land-Mobile Network

Public Land-Mobile Network (PLMN) is a European term used to describe all mobile wireless networks that use earth-based stations rather than satellites. PLMN is the mobile equivalent of the PSTN.

PMP: Paging Message Processor

Paging Message Processor (PMP) is a Radio Paging Terminal or equivalent message processing system.

PMR: Private Mobile Radio

Private Mobile Radio (PMR) is for use within a defined user group such as the emergency services or by the employees of a mining project.

PN: Pseudo-Noise

Pseudo-Noise (PN), also known as pseudorandom noise (PRN), is a signal similar to noise which satisfies one or more of the standard tests for statistical randomness. Although it seems to lack any definite pattern, pseudorandom noise consists of a deterministic sequence of pulses that will repeat itself after its period.

PNCQPSK: Pseudo-Noise Complex Quadrature

Pseudo-Noise Complex Quadrature Phase Shift Keying (PNCQPSK) is the spreading technique that uses basic complex scrambling and Pseudo-Noise (PN) signals for Is and Qs. PNCQPSK is used in 3G mobile wireless technologies.

PoC: Push to Talk over Cellular

Push To Talk Over Cellular (PoC) is a walkie-talkie type service provided over a cellular phone network. A push to talk over a cellular system typically supports telephony services. There are proprietary implementations, and the Open Mobile Alliance defines standards for PoC. Push to talk calls are half duplex communications — while one person speaks, the other(s) listen. A push-to-talk connection is typically connected virtually instantaneously. A single press reaches an active talk group. Users no longer need to make several calls to coordinate with a group.

POCSAG: Post Office Code Standard Adviso

Post Office Code Standard Advisory Group (POCSAG), also known as RPC1 (a CCIR standard taken directly from POCSAG), is a group formed by the British Post Office to design a non-proprietary digital paging code. The code that they designed is now implemented by most pager manufacturers and is the most widely used code to date. The POCSAG code can be operated at three speeds, 512, 1200, and 2400 bits per second. POCSAG is gradually being replaced by FLEX.

Polarization diversity

Polarization diversity is a diversity technique where antennas of different polarizations, i.e., horizontal and vertical, are used to provide diversity reception. The antennas take advantage of the multipath propagation characteristics to receive separate uncorrelated signals.

Power control

Power control is a technique for managing the transmit power in base stations and mobiles to a minimum level needed for proper performance. Downlink power control applies to base stations and uplink power control to mobiles. Power control is used in nearly all wireless systems to manage interference, and in the case of mobiles, to extend battery life.

PQA: Palm Query Applications

Palm Query Applications (PQA) is an Internet clipping application developed from HTML code and run on Palm PDAs. The application is designed to streamline the flow to the PDA to minimize the number of kilobytes sent and ultimately paid for.

PRBS: Pseudo-Random Binary Sequence

Pseudo-Random Binary Sequence (PRBS), commonly used to performance test PCM systems, is a digital signal having framing information and using pseudo-noise in the individual traffic channels.

PRMA: Packet Reservation Multiple Access

Packet Reservation Multiple Access (PRMA) is a packet-based TDMA concept where the users contend for the time slots. In situations where the system is not near capacity, a user can reserve a time slot for future uses.

Processing gain

Processing gain is the amount of gain, in dB, provided by the spreading code in a CDMA system, usually the ratio of the spreading rate to the information rate.


Propagation is the process an electromagnetic wave undergoes as it is radiated from the antenna and spreads out across the physical terrain. See also propagation channel.

Propagation channel

Propagation channel is the physical medium electromagnetic wave propagation between the transmit and receive antennas, and includes everything that influences the propagation between the two antennas.

PSD: Power spectral density

Power spectral density (PSD) refers to the amount of power per unit (density) of frequency (spectral) as a function of the frequency. The power spectral density, PSD, describes how the power (or variance) of a time series is distributed with frequency. By knowing the power spectral density and system bandwidth, the total power can be calculated.

PSK: Phase Shift Keying

Phase Shift Keying (PSK) is a broad classification of modulation techniques where the information to be transmitted is contained in the phase of the carrier wave.

PSTN: Public Switched Telephone Network

Public Switched Telephone Network (PSTN) is the network of the world's public circuit-switched telephone networks, providing commercial telephony services. Originally as a network of fixed-line analog telephone systems, the PSTN is now almost entirely digital and includes mobile as well as fixed telephones.

PTT: Post, Telecommunications&Telegr

Post, Telecommunications&Telegraph (PTT) is typically the Ministry of Post, Telecommunications and Telegraph. It is also a term to describe the incumbent, dominant operator in a country, many of which are being or have been privatized.

Punctured code

Punctured code is a technique used in convolutional decoders that allows a limited number of coded bits to be deleted to greatly simplify processing in the codec. This is extremely useful with long codes.

PUSC: Partially Used Sub-Carrier

Partially Used Sub-Carrier (PUSC), sometimes called Partially Used Sub-Channel, was first defined in the IEEE802.16d (Fixied WiMAX) for the OFDMA PHY layer. Basically, the IEEE802.16e (Mobile WiMAX) uses the same OFDMA sub-channelization structure and its extension to address mobility has retained the OFDMA concept for FUSC (Fully Used Sub-carrier) and PUSC. Use of FUSC, mainly in the DownLink, and PUSC in both DL and UL as defined in 16d or 16e with Reuse 1 will endow the WRAN system with the needed capability and flexibility to configure the WRAN in different scenarios with manageable interference among the Base Stations where different Service Providers may deploy the system in the same region using the same free TV channel.

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