电信专业英英词典P-1（在线收听）

　　P-MAC

　　packet media access controller

　　PAD

　　packet assembler-disassembler

　　PCB

　　printed circuit board

　　PDS

　　premises distribution system

　　Personal Communications

　　Personal communications provides at least one human operator with direct terminal access and real time or near real time interactive communications with a remote human opera tor or an information system resource. Personal communications can refer to a broad range of services, systems and equipment, e.g., facsimile machines, landline telephones, cellular tele phone systems and emerging personal communication system (PCS) adjuncts, and a variety of radio systems including pagers, hand-held remote data entry terminals, and autonomous citizen-band- like radio systems.

　　PHY

　　physical-layer protocol

　　PMD

　　physical-layer media-dependent

　　Point-of-presence (POP)

　　A POP is a physical location within a LATA that an IXC establishes for the purpose of gaining access to BOC/LEC networks within the LATA using LEC provided access services. An IXC may have more than one POP within a LATA and the POP may support public and private, switched and non switched services.

　　POP

　　point-of-presence

　　POT

　　point of termination