R R&D Research and Development. RACE 1. Random access computer equipment. 2. Research and development for advanced communications in Europe, an association in the European Economic Community. RACF Resource Access Control Facility (IBM). rack Frame upon which equipment is mounted. rackmount modem A standalone framework that stores multiple adapters and connects to the RS-232 port of a PC. RAD Rapid Application Design. radial acceleration The rate at which a track on an optical disc accelerates toward and away from the center. radio channel Band of radio frequencies wide enough to allow radio communications. radio circuit Circuit fixed between two points using a radio bearer. radio common carrier (RCC) Communications common carrier that provides radio paging and mobile telephone services to the public. radio communications Telecommunications by method of radio waves. radio frequency (RF) Frequencies on the electromagnetic spectrum associated with radio transmission (usually above 150KHz). radio frequency interference (RFI) Noise caused by any source that generates radio waves at the same frequency and along the same path of another radio wave which interferes with radio reception. radio wave Electromagnetic waves of frequencies between 10KHz and 3,000,000MHz, propagated without guide in free space. RAID Redundant Array of Inexpensive Disks. A storage device that uses several hard disks working in tandem to increase bandwidth output and/or to provide fault tolerance and backup. Data segments are either distributed across all the disks, or duplicated on each disk, depending on the level or implementation of RAID being used. RAM Random Access Memory; a memory device used for storage purposes in which data can be entered and retrieved from any location. It is considered the working memory. RAM cache Also known as cache memory, a reserved section of main memory (RAM) or a special bank of high-speed memory that is used to improve computer performance. RAMDAC Random Access Memory Digital-to-Analog Converter. The chip on a VGA board that translates the digital representation of a pixel into the analog information needed for display on the monitor. ramp In graphics, the consistency with which a gradated color flows from one to the other. random access Refers to the storage of data and the ability to retrieve it directly rather than in a sequential manner. RAS 1. Rapid-Access Storage 2. Reliability, Availability, Service (IBM). RASIS Reliability, Availability, Serviceability, Integrity, and Security. raster Images that are stored and displayed in bitmap (pixels in horizontal and vertical rows) form. raster display The most common type of display terminal. Uses pixels in a column-and-row array to display test and images. raster font A set of characters for screen display or printing that is stored as bitmaps in specific character sizes. Compare with vector fonts. raster graphics Images defined as a set of pixels or dots in a column-and-row format. raster image processor RIP. The software and hardware that translates a page description language (PDL) like PostScript, or graphics output into the dots to be used by an output device's print engine. rate averaging Method of fixing prices for telephone calls based on distance rather than routing path. rate base Total invested dollars on which a regulated telephone company is entitled to earn a specified rate of return. rate center A geographic location used to calculate distances between communications interchanges for computing rates. rate of return Percentage of net profit that a telephone company is licensed to earn on its rate base. rate period The specific portion of a 24-hour period or the specific day of the week during which a particular rate is charged for toll calls. ray tracing The technique for creating reflections and shadows in computer graphics for more realistic, 3-D effect. Takes the location of the light source and computes where the light rays would fall. RBHC Regional Bell Holding Company. RBOC See Regional Bell Operating Company. RC paper Resin-coated photographic paper; commonly used for imager output. RCC See radio common carrier. RDBMS Relational Data Base Management System. RDOS Real-Time Disk Operating System (Data General). RDSS Radio determination satellite service. RDY Ready. read To retrieve information from a peripheral device. A read head locates the sector of data, senses the magnetic biases of the substrate (that's the reading part) and translates the pulses to the disk controller, and on to the processor. read only memory (ROM) That portion of a computer's memory that is programmed electrically by the manufacturer. It is unchangeable and is unaffected by a power loss. read/write head Magnetic head able to store, extract, or erase dots representing data on magnetic media. real storage The primary storage in an addressable (virtual) storage system. real storage address Location of data in memory. realtime Response to requests for service on demand, in contrast to time-sharing, in which all requests for service are responded to on a round-robin basis in a predetermined time sequence. realtime clock Keeps time within the computer and develops readable characters or signals for the computer to allow computation of elapsed time between events. reasonableness checks Tests on information reaching or being transmitted from a system to ensure that the data in question lies within a given range. It is one means of protecting a system from data transmission errors. recall The act of calling an operator into a connection that was established by an operator. receive only (RO) A terminal with a page only printer and no keyboard or transmission capability. receiving calls Audible and visual tones alert a station of incoming calls; station can be either in off-hook or on-hook position. See also call waiting. record A combination of related data items considered as one unit of information. record communications A form of communication that creates a hardcopy record of transmission (e.g., teleprinters or FAX machines). recorded announcement intercept See intercept treatment. recording zone The ring-shaped area of an optical disk on which data can be recorded. recovery Method of resuming operation following a hardware or software failure and subsequent restoration of service. recovery from fallback Restoration to its former condition of a system that has switched to a fallback mode of operation when the cause of the fallback has been removed. The recovery process can involve updating information in the files to produce two duplicate copies of the file. redirector An IBM/Microsoft term for a station on a LAN that receives information from a network server and redirects it to appear to the local user as a local resource. redundancy In data transmission, the portion of characters and bits that can be eliminated with no loss of information. redundancy check A hardware or software check based on the systematic insertion of components or characters used especially for checking purposes. redundant electronics A telecommunications facility that uses two separate electronic devices to transmit the telecommunications signal so that if one device fails to operate, the signal will continue without interruption. reference track A special magnetic track placed on floptical diskettes used by the drive to calibrate the optical tracking system with respect to the magnetic recording tracks. reflective art Artwork whose image does not appear by light shining through it or emitting from it, but is only visible because light is reflected from it. reflective read The type of optical medium where the laser to be read is reflected from the medium. refresh To continuously charge a device that cannot hold its content. CRTs must be refreshed because the phosphors hold their glow for only a few milliseconds. refresh rate Measure of how often the image on a CRT is redrawn; expressed in hertz, or cycles. regenerative repeater Device that amplifies, reshapes, and retimes incoming signals and then retransmits them on an outgoing circuit. Also called regenerator. Regime The various steps involved in using FTAM to access, transfer, or manage a file. Regional Bell Operating Company (RBOC) Seven operating companies that emerged from divestiture of AT&T, each of which own two or more Bell operating companies (BOCs). regional center Any of the highest rank control centers (Class 1 offices) that connect sectional centers of the telephone system together. register A device that accepts and stores information, usually a called number, then uses that information to control the switch. registration The precision with which CMYK primary colors are placed on the page relative to each other. Misregistration results in color inaccuracies, unclear edges and reduced image clarity. regression test system A tool that automates the organization and execution of tests and systematically stores the results. Using the concepts of regression testing, it runs the tests and compares the results against expected results. regression testing A methodology that supports the continued testing of a program as features are revised or added and compares the results of those tests against the expected results. reinitiation time The time required for a device or system to restart (usually after a power outage). relational data base Data base that defines multiple and complex relations between data in the form of tables. relay An electromagnetic switching unit used to operate a circuit. release with howler Loud tone (howler) transmitted over the telephone line when a phone is left off-hook for a time without placing a call. The CO then disconnects the line until the receiver is put on-hook again. relocatability The ability for programs or data to be situated in various memory locations at different times without requiring modification to the program. REMDOS Remote Disk Operating System (Datapoint) remote access A PBX feature that allows a user at a remote location to access PBX features by telephone (e.g., to use WATS lines); individual authorization codes are often required. remote computing Use of a removed terminal to manipulate information on a computer. remote data concentration Multiplexing a number of low-end devices or carriers on to one high-speed line between a remote terminal and a central processor. remote file access (RFA) Ability to read from and write to files placed on a remote system. remote job entry (RJE) Process of submitting batch programs to a mainframe for execution, and returning the results from a remote point. RJE requires a printer/reader terminal, called an RJE terminal. remote maintenance Ability of a remote terminal to access a PBX maintenance menu. Remote Monitoring Management Information Base (RMO A standard for network management products based on the Simple Network Management Protocol (SNMP). remote processing The use of a computer system for processing data transmitted from remote locations. remote resources A device that is available through the network, but is not connected to the local node. render To draw a real-world object as it actually appears. reorder signal Audible tone, faster than a busy signal, that indicates all switching paths needed to connect a call are in use. repeater A component that reconstitutes, reamplifies, or reshapes signals into standard voltages, currents, and timing. replication Using more than one of an item, be it hardware or software, to increase security or to allow for more traffic to flow. repository An evolutionary extension of data dictionary systemsthat takes the facilities of the dictionary for data integration andadds the control services (i.e., security, versioning, and objectmanagement) that facilitate control integration. The repository mustallow access to all types of data and data definitions. REPROM Reprogrammable Read-Only Memory. request for information (RFI) Request sent to vendors soliciting information regarding their products. request for proposal (RFP) Sent to interested vendors after an RFI, it asks for a price scheme that meets with the potential buyer's requirements. request to send (RTS) A basic data set interchange lead (defined in an EIA Standard). rerun point Preselected points in a program useful in case of error. If an error is detected, the program is repeated from the rerun point rather than starting from the beginning. RES Remote Job Entry Services (IBM) resale carrier Business that purchases services from another business at a bulk rate and resells portions of those services to multiple users. Also called reseller. reserve power Storage batteries that back-up the primary power source in a computer or telephone system. residual error rate, undetected error rate Ratio of bits, unit elements, characters or blocks, incorrectly received but undetected or uncorrected by the error-detecting equipment, to the total number of bits sent. resolution The number of points on a video display which determine the quality of the display. Responder A server (application or virtual file store) that accepts a FTAM file transfer/access request. response time The system reaction time to a given input. The time interval between pressing the send key of a terminal and the display of the first character of the system's reply. restriction See Inward restriction, outward restriction, toll restriction, and fully restricted stations. retirement The term that describes the decision to throw away a recording medium when it has too many defects. retrieval, message The process of searching a log of transmitted messages for a particular message, on the basis of filing time, message number, message address(es), or a combination of these. When located, the message is sent to the requestor. return key Keyboard button that, when pressed, ends one line of data and begins another. reverse channel Used for transmitting supervisory or error control signals. The flow is opposite to that of information transfer and bandwidth is usually lower. reverse video Display in which characters are highlighted by inverting the normal display mode. reverse-battery supervision Way of indicating to the CO that a called telephone has gone off-hook. The voltage of the line at the originating end is reversed. rewritable optical Optical media from which data can be erased and new data added. REX 1. Real-Time Executive Routine (Unisys). 2. Real-Time Executive System (Hitachi). RF See Radio frequency. RFA Remote File Access; capability to read from and write to files placed on a remote system. RFI See radio frequency interference or request for information. RFP See request for proposal. RFQ Request For Quote. RFS AT&T's Remote File Sharing protocol. RGB Red, Green, Blue. The primary colors, called additive colors, used by color monitor displays and TVs. The combination and intensities of these three colors can represent the whole spectrum. RGB Video Signal A video signal in which the red (R), green (G), and blue (B) picture components are present as individual signals. RIF Routing information field. RIFF Resource Interchange File Format. Platform-independent multimedia format jointly introduced by IBM and Microsoft. Allows audio, images, animation, and other multimedia elements to be stored in a common format. ring again See last number redial. ring network A network topology with decentralized control in which messages are passed around the ring from node to node until they reach their designation or address; most use the token-passing access method. ringdown Signaling used in manual systems where picking up one phone automatically rings another. The telephone's ringing gains an operator's attention, and initiates a current that is sent over the line to engage a lamp and drop a self-locking relay. ringing key Key that transmits a ringing current. ringing signal Any transmitted signal (AC or DC) that alerts someone or something at the other end to an incoming call. RIP 1. Raster Image Processor. The software and hardware that translates bitmap and PDL instructions from a graphics program to the print mechanism. 2. Routing Information Protocol. A routine protocol in TCP/IP and NetWare used to identify all attached networks as well as the number of router hops required to reach them. 3. Remote Imaging Protocol. A graphics format from TeleGrafix Communications, designed for transmitting graphics over low-speed lines. RISC (Reduced Instruction Set Computer) The theory behind the RISC chip is that simple instructions that can be implemented directly in hardware can execute faster than complex instructions that require the use of microcode. RISC microprocessors are available in proprietary versions such as the IBM RT PC and general licensing versions such as Sun Microsystem's SPARC (Scalable Processor Architecture) and Intel's 860. RJE See remote job entry. RLE Run Length Encoding. A compression algorithm used in Group III (fax-standard) compression. RMON Remote monitoring. RMON MIB See remote monitoring management information base. RMS Recovery Management Support. RO 1. Read Only. 2. Register Output. 3. See receive only. roaming Allowing the cellular telephone user to receive calls outside the primary service area, usually a extra charge is incurred. ROH Receiver off-hook. Rollback An error recovery procedure used to preserve the stateof a file recapturing file status and content before a commitment. ROM Read Only Memory; that portion of a computer's memory that is programmed electrically by the manufacturer. It is unchangeable and is unaffected by a power loss. room cutoff In unoccupied hotel/motel rooms, the phone is restricted from completing outgoing calls. room status To assist the housecleaning staff, this feature stores and displays the occupancy and status of any given hotel/motel room. ROS Read-Only Storage. ROSE Remote Operations Service Element. Rosette The visible pattern of the four-color printing dots on paper or proofing material. rotary camera A microform camera system in which documents are recorded on the fly (the documents are fed and the film is advanced simultaneously by synchronized transport systems). rotary dial In a switched system, the conventional telephone dialing method that creates a series of pulses to identify the called station. rotary hunt An arrangement allowing calls placed to seek an idle circuit in a prearranged multi-circuit group and find the next open line to establish a through circuit. rotary output to central office System that translates a tone-dialed telephone number into rotary dial pulses and transmits these signals to the central office. rotational latency The time required for a disk or disc to rotate under the read/write head until the correct sector comes around. route The process of directing a message to the appropriate line and terminal, based on information contained in the message header. route advance Another type of automatic route selection that allows the caller to select the first-choice trunk group. route mile The geographical measure defined as one physical mile of fiber optic cable, regardless of the number of telecommunications paths within the cable. route optimization See least cost routing. route selection See automatic route selection. router A device that selects the best travel path for data and directs the information accordingly. routine Program instructions that accomplish a frequently-run task. routing Choosing the correct circuit path for a message. routing code Combination of characters or digits required to route a transmission to a desired location. routing indicator An address, or group of characters, in the heading of a message defining the final circuit or terminal to which the message is to be delivered. routing table A data matrix containing available routes and such parameters as user class of service and call destination; used by the switching software to select a route for a given call. RPC 1. Remote Processor Controller. 2. Remote Procedure Call. RPG Report Program Generator. RPG II Commercially-oriented programming language. rpm Revolutions per minute. RPQ Request for price quotation. RPROM Reprogrammable Read-Only Memory. RPS 1. Real-Time Programming System (IBM). 2. Remote Processing System (Unisys). 3. Rotational Position Sensing. RPU 1. Remote Processing Unit. 2. Regional Processing Unit. RS-232C A standard set by the EIA for the interface between data communications equipment (DCE) and data terminal equipment (DTE). RS-422A A standard set by the EIA for the electrical characteristics of balanced-voltage digital interface circuits. RS-423A A standard set by the EIA for the electrical characteristics of unbalanced-voltage digital interface circuits. RS-449 A standard set by the EIA that is compatible with RS-232C, but supports higher data rates at greater distances. The RS-449 interface is a 37-pin connector that supports transmission at data rates up to 2M bps at distances up to 200 feet between DTE and DCE. The additional connections implement more control functions. RSA 1. Remote Session Access. 2. See Rural service area. RSAM Record Sequential Access Method. RSCS Remote Spooling Communications Subsystem (IBM). RSP 1. Reader/Sorter Processor. 2. Required space character. RSTS Resource Time-Sharing Operating System (Digital Equipment). RTCC Real-Time Communications Control. RTL 1. Run-Time Library. 2. Resistor Transistor Logic. RTNR (ring tone no reply) A low tone that is one second on and three seconds off indicates that ringing current is being sent by the central office to the person receiving the call. The person making the call can hear the ringing tone, but the person receiving the call doesn't hear anything. RTOS Real-Time Operating System (Control Data). RTP Rapid Transport Protocol. RTS 1. Request-To-Send; a basic data set interchange lead (defined in an EIA Standard). 2. Real-Time System. 3. Reliable Transfer Server. RU Run Unit. Rural service area (RSA) When the Federal Communications Commission (FCC) issued cellular radio licenses it divided the United States into Rural Service Area (RSA) and Metropolitan Statistical Area (MSA) markets. The FCC designated 428 rural markets across the country, that licenses cellular operators for the FCC. RWM Read/Write Memory.