Telecommunications — page 8 of 85

Telecommunications terms

701. beam steering Changing the direction of the main lobe of a radiation pattern. Note: In radio systems, beam steering may be accomplished by switching antenna elements or…
702. beamsplitter A device for dividing an optical beam into two or more separate beams. Note: An example of a beamsplitter is a partially reflecting mirror.
703. beamwidth 1. In the radio regime, of an antenna pattern, the angle between the half-power (3-dB) points of the main lobe, when referenced to the peak effective…
704. bearer channel See B channel.
705. bearer service A telecommunications service that allows transmission of user-information signals between user-network interfaces. See B channel, service access.
706. beating See heterodyne.
707. beeping Synonym paging, radio paging.
708. bel (B) A unit of measure of ratios of power levels, i.e., relative power levels. Note 1: The number of bels for a given ratio of power levels is calculated by…
709. bell (BEL) character A transmission control character that is used when there is a need to call for user or operator attention in a communications system, and that usually…
710. Bell Operating Company (BOC) Historically, any of the 22 operating companies that were divested from AT&T by court order. Note: Cincinnati Bell Telephone Co.
711. Bell-La Padula security model 1. [A] formal state-transition model of a computer security policy that describes a formal set of access controls based on information sensitivity and…
712. bend loss See macrobend loss, microbend loss.
713. benign (beh-NINE) Not cancerous. Benign tumors may grow larger but do not spread to other parts of the body.
714. benign environment [In security, a] nonhostile environment that may be protected from external hostile elements by physical, personnel, and procedural security…
715. BER Abbreviation for bit error ratio.
716. BERT Acronym for bit error ratio tester.
717. beta test A secondary software product test involving select or voluntary participants before the product is marketed to the general public.
718. BETRS Abbreviation for basic exchange telecommunications radio service.
719. between-the-lines entry Unauthorized access to a momentarily inactive terminal, of a legitimate user, assigned to a communications channel.
720. BEX Abbreviation for broadband exchange.
721. bi-sync Abbreviation for binary synchronous (bi-sync) communication.
722. bias (BY-us) In a scientific research study or clinical trial, a flaw in the study design or the method of collecting or interpreting information.
723. bias distortion Signal distortion resulting from a shift in the bias. 2. In binary signaling, distortion of the signal in which all the significant intervals have…
724. biased In the generation of pseudorandom or random numbers, pertaining to or describing a condition that renders the more likely occurrence of some numbers or…
725. biconical antenna An antenna consisting of two conical conductors, having a common axis and vertex, and extending in opposite directions.
726. bidirectional asymmetry In data transmission, the condition that exists when information flow characteristics are different in each direction.
727. bidirectional connection Association established between two higher layer entities for which information is transmitted between both entities. [After T1.629-1999]
728. bidirectional coupler See directional coupler.
729. bidirectional symmetry The condition that exists when information flow characteristics are the same in each direction.
730. big-endian A common difference between machines is the order in which they store the individual bytes of multi-byte numerical data.
731. BIH French abbreviation for International Time Bureau. See International Atomic Time.
732. bilateral control Synonym bilateral synchronization.
733. bilateral synchronization A synchronization control system between exchanges A and B in which the clock at exchange A controls the data received at exchange B and the clock at…
734. billboard antenna An array of parallel dipole antennas with flat reflectors, usually positioned in a line or plane.
735. binary Mathematical base 2, or numbers composed of a series of zeros and ones. Since zero's and one's can be easily represented by two voltage levels on an…
736. binary code A code, the elements of which can assume either one of two possible states.
737. binary digit (bit) See bit.
738. binary element A constituent element of data that takes either of two values or states. Note: Binary element should not be confused with binary digit.
739. binary exponential backoff See truncated binary exponential backoff.
740. binary modulation The process of varying a parameter of a carrier as a function of two finite, discrete states.
741. binary notation Any notation that uses two different characters, usually the digits 0 and 1. Note: Data encoded in binary notation need not be in the form of a pure…
742. Binary number A number that can be represented using only two numeric symbols - 0 and 1. A number in base 2.
743. binary string Synonym bit string.
744. binary synchronous (bi-sync) communication A character-oriented, data-link-layer protocol. Note: The bi-sync protocol is being phased out of most computer communication networks in favor of…
745. binary-coded decimal (BCD) Pertaining to the representation of a decimal digit by a unique arrangement of no fewer than four binary digits.
746. binary-coded decimal (BCD) notation A binary notation in which each of the decimal digits is represented by a binary numeral.
747. binary-coded decimal code Synonym binary-coded decimal notation.
748. binary-coded decimal interchange code See binary-coded decimal notation.
749. binary-coded decimal representation Synonym binary-coded decimal notation.
750. binding The ability of molecules to bind each other non-covalently because of the exact shape and chemical nature of parts of their surfaces.
751. binding of functionality An aspect of the assessment of the effectiveness of a Target of Evaluation, namely the ability of its security enforcing functions and mechanisms to work…
752. Biometric A physical or behavioral characteristic of a human being.
753. Biometrics (BY-oh-MEH-triks) The science of collecting and analyzing biologic or health data using statistical methods.
754. biphase modulation Synonym phase-shift keying.
755. bipolar signal A signal that may assume either of two polarities, neither of which is zero. Note 1: A bipolar signal may have a two-state non-return-to-zero (NRZ) or a…
756. bipolar violation In a bipolar alternate mark inversion (AMI) signal, a "one" condition (mark, pulse) having the same polarity as its predecessor. [After T1.408-1990]
757. birefringence In a transparent material, anisotropism of the refractive index, which varies as a function of polarization as well as orientation with respect to the…
758. birefringent medium See birefringence.
759. BIRRDS The Telcordia™ Business Integrated Routing and Rating Database System contains data in the routing and rating of calls.
760. birthday phenomenon The phenomenon stating that, for a category size of 365 (the number of days in a year), after only 23 people are gathered, the probability is greater than…
761. bistable Pertaining to a device capable of assuming either one of two stable states.
762. bistable circuit Synonym flip-flop.
763. bistable multivibrator Synonym flip-flop.
764. bistable trigger circuit Synonym flip-flop.
765. Bit A bit ( B inary dig IT ) is the smallest unit of computer data. A bit consists of either 0 or 1. There are eight bits in a byte.
766. bit configuration The sequence of bits used to encode a character.
767. bit density The number of bits recorded per unit length, area, or volume. Note: Bit density is the reciprocal of bit pitch. Synonym recording density.
768. bit depth Synonym bits per pixel.
769. bit error A bit that is transferred from the source to the destination within the assigned time slot, but that, when delivered, is of a different value from that…
770. bit error rate Deprecated term. See bit error ratio.
771. Bit Error Rate Test A test performed on a digital facility/service which counts erroneous bits and divides them by the bits sent over a set period of time.
772. bit error ratio (BER) The number of erroneous bits divided by the total number of bits transmitted, received, or processed over some stipulated period.
773. bit error ratio tester (BERT) A testing device that compares a received data pattern with a known transmitted pattern to determine the level of transmission quality.
774. bit interleaved parity N (BIP-N) A method of error monitoring. If even parity is used, an N bit code is generated by the transmitting equipment over a specified portion of the signal in…
775. bit interval See bit, character interval, unit interval.
776. bit inversion The changing of the state of a bit to the opposite state. 2. The changing of the state that represents a given bit, i.e.
777. bit masking In embedded ADPCM (adaptive differential pulse-code modulation), the process of discarding the enhancement bits. [T1.310-1991]
778. bit pairing The practice of establishing, within a code set, a number of subsets that have an identical bit representation except for the state of a specified bit.
779. bit period (T) The amount of time required to transmit a logical one or a logical zero. [T1.106-1988]
780. bit position A character position in a word in a binary notation.
781. bit rate (BR) In a bit stream, the number of bits occurring per unit time, usually expressed in bits per second.
782. bit robbing In digital carrier systems, the practice or technique of preempting, at regular intervals and for the purpose of transmitting signaling information, one…
783. bit slip In digital transmission, the loss of a bit or bits, caused by variations in the respective clock rates of the transmitting and receiving devices.
784. bit string A sequence of bits that is actually being thought of as a sequence of bits, for once.
785. bit stuffing The insertion of noninformation bits into data. Note 1: Stuffed bits should not be confused with overhead bits.
786. bit stuffing rate See nominal bit stuffing rate.
787. bit synchronization Synchronization in which the decision instant is brought into alignment with the received bit, i.e., the basic signaling element.
788. bit synchronous operation Operation in which data circuit terminating equipment (DCE), data terminal equipment (DTE), and transmitting circuits are all operated in bit synchronism…
789. bit-by-bit asynchronous operation In data transmission, an operation in which manual, semiautomatic, or automatic shifts in the data modulation rate are accomplished by gating or slewing…
790. bit-count integrity (BCI) In message communications, the preservation of the exact number of bits that are in the original message. 2.
791. bit-rate•distance product See bandwidth•distance product.
792. bit-sequence independence A characteristic of some digital data transmission systems that impose no restrictions on, or modification of, the transmitted bit sequence.
793. bit-stepped Pertaining to the control of digital equipment in which operations are performed one step at a time at the applicable bit rate.
794. bit-stream transmission In bit-oriented systems, the transmission of bit strings. 2. In character-oriented systems, the transmission of bit streams that represent characters.
795. biternary transmission Digital transmission in which two binary pulse trains are combined for transmission over a channel in which the available bandwidth is sufficient for…
796. bitmap In computer graphics, a representation of an image (which category includes characters) by code or a coding scheme that defines (a) the position of pixels…
797. bitmapped graphics In computer graphics, an image created with, or represented by, a matrix of pixels. Synonym [loosely] raster graphics.
798. BITNET Abbreviation for Because It's Time NETwork. An early (ca. 1981) store-and-forward digital communications network interconnecting universities and research…
799. bits per inch (b/in) A unit used to express the linear bit density of data in storage. Note: The abbreviation "bpi" is not in accordance with international standards, and is…
800. bits per pixel (BPP) In a digitized image, the number of bits used to represent the luminance (brightness, gray scale) and chroma (color) information contained in each pixel.