PABX 

Private Automatic Branch Exchange

PAC 

PPTP Access Concentrator

PACCH 

Packet Associated Control Channel

PAD 

Packet Assembly/Disassembly

PAGCH 

Packet Acces Grant Channel

PAN 

Personal Area Ntwork

PAP 

Password Authentication Protocol or Push Access Protocol (WAP)

PBCCH 

Packet Broadcast Control Channel

PBX 

Private Branch Exchange

PC 

Personal Computer

PCCCH 

Packet Common Control Channel

PCCH 

Paging Control Channel

PCH 

Paging Channel

PCI 

Peripheral Component Interconnect

PCM 

Pulse Code Modulation

PCMCIA 

Personal Computer Memory Card International Association

PCN 

Personal Communications Network

PCR 

Peak Cell Rate

PCS 

Personal Communications Services

P-CSCF 

Proxy Call Session Control Function

PCU 

Packet Control Unit

PDA 

Personal Digital Assistant

PDC 

Personal Digital System (Japan)

PDC 

Packet Data Communication

PDCH 

Packet Data Channel

PDF 

Portable Document Format

PDH 

Plesiochronous Digital Hierarchy

PDN 

Packet Data Network

PDP 

Packet Data Protocol

PDSCH 

Physical Downlink Shared Channel

PDTCH 

Packet Data Traffic Channel

PDU 

Packet Data Unit

PDU 

Protocol Data Unit

PG 

Peer Group

PG 

Processing Gain

PGL 

Peer Group Leader

PHS 

Personal Handy System (Japan)

PHY 

OSI Physical Layer

PhyCH 

Physical Channels

PI 

Paging Indication

PICS 

Protocol Implementation Conformance Statement

PIM 

Personal Information Management

PIN 

Private Identification Number

PIR 

Peak Information Rate

PLL 

Phase Lock Loop

PLMN 

Public Land Mobile Network

PM 

Performance Management

PMS 

Performance Management System

PNCH 

Packet Notification Channel

PNNI 

Private Network-to-Network Interface

PNP 

Private Numbering Plan

PNS 

PPTP Network Server

POH 

Path OverHead

POI 

Point Of Interconncetion

PON 

Passive Optical Network

POP 

Protocol

POP 

Point of Presence

POP3 

Post Office Protocol 3

POS 

Packet Over Sonet

POS 

Point Of Sale (all shops)

POTS 

Plain Old Telephone Service

PPCH 

Packet Paging Channel

PPG 

Push Proxy Gateway

PPP 

Point to Point Protocol

PPS 

PrePaid System

PPTP 

Point to Point Tunnelling Protocol

PRA 

Primary Rate Access to ISDN

PRACH 

Packet Random Access Channel

PRE 

Primary Rate Equipment

PRI 

Primary Rate Interface

PS 

Packet Switched

PSCCCH 

Physical Shared Channel Control Channel

PSO 

Protocol Supporting Organization

PSPDN 

Packet-Switched Public Data Network

PSTN 

Public-Switched Telephone Network

PT 

Payload Type

PTI 

Payload Type Indicator

PTM 

Point-To-Multipoint

PTM-G 

PTM Group call

PTM-M 

PTM Multicast

PTM-SC 

PTM Service Center

PTP 

Point-To-Point

PTSE 

PNNI Topology State Element

PTSP 

PNNI Topology State Packet

PU 

Payload Unit

PUF 

Power Up Function

PUK 

PIN Unlocking Key

PVC 

Permanent Virtual Circuit

PVCC 

Permanent Virtual Channel Connection

PVP 

Permanent Virtual Path

PVPC 

Permanent Virtual Path Connection