and Assignment protocol. Public Utility Commission. (In USA.) (Multiple access technique. See also FPODA and Permanent Virtual Circuit. (Method for establishing CPODA.) a virtual circuit link between two nominated points. Path Overhead. (Information used in SDH trans- See also SVC) mission structures.) Pulse Width Modulation. (Analogue modulation Problem Oriented Language. (A term sometimes technique in which the width of pulses is varied. used to describe a high level computer programming Also called Pulse Duration Modulation, PDM, or language, such as Cobol or Fortran.) Pulse Length Modulation, PLM.) Acronyms 62/15 interface Adaptor. Real Time Network Routing. (Dynamic traffic rout- Q Adaptor Function. ing strategy being implemented by AT&T.) Quadrature Amplitude Modulation. (A modulation Request To Send. (Handshaking routine used in an- technique which varies the amplitude of the signal. logue transmission, such as by modems.) Used in dial up modems. Also known as Quadrature Reliable Transfer Service Element. Sideband Amplitude Modulation or QSAM.) Regie des Telegraphes et des Telephones. (Belgian Quantising Distortion. PTT.) Quality of Service. (Measure of service performance Return to Zero. (A digital transmission system in as perceived by the user.) which the binary pulse always returns to zero after Quadrature Partial Response System. (Signal modu- each bit.) lation technique.) Quadrature Phase Shift Keying. (Signal modulation technique.) Step by Step. (Refers to a Strowger electromechan- ical switch.) Standards Australia. (Australian national standards Research and development in Advanced Communi- organisation.) cation technologies in Europe. Special Access Code. (Special telephone numbers Research and Development. e.g. 800 service.) RADARSAT Radar Satellite. Standards Association of New Zealand. RAISE Rigorous Approach to Industrial Software Engineer- Service Access Point. (Port between layers in the ing. (Esprit project.) OSI seven layer model, one for each of the layers, Regional Administrative Radio C