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A technique applied to a DS1 frame to ensure pulse density requirements are met, where bits 2 through 193 of each frame are scrambled to minimize the occurrence of all-zero octets. When an all-zero octet is contiguous to another octet with zeros and they would combine to violate the ones density requirement, an algorithm is invoked where some all-zero octets are replaced by an address chain. The reverse algorithms are performed by the receiving terminal.
- Browse Related Terms: acceptance test, acceptance testing, acceptance trial, alarm event, conformance test, event, measured blocking threshold, operations system, reference waveform, self-testing circuit, system administration, ZBTSI (zero-byte time slot interchange)
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: A bit-stuffing technique used with bit-oriented protocols to ensure that six consecutive "1" bits never appear between the two flags that define the beginning and the ending of a transmission frame. Note: When five consecutive "1" bits occur in any part of the frame other than the beginning and ending flag, the sending station inserts an extra "0" bit. When the receiving station detects five "1" bits followed by a "0" bit, it removes the extra "0" bit, thereby restoring the bit stream to its original value. Synonyms zero insertion, zero stuffing.
- Browse Related Terms: self-delineating block, Sentinel, zero insertion, zero stuffing, zero-bit insertion
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In a communication system, a point at which the reference level is 1 mW, i.e., 0 dBm. Note: The actual power level of the communications traffic is not necessarily 0 dBm. It is usually below the reference level. The reference is for system design and test purposes. Synonym zero transmission level point.
- Browse Related Terms: Accuracy, ambient noise level, Equal Level Echo Path Loss, fading distribution, net gain, relative transmission level, sensitivity, test tone, thermodynamic temperature, transmission level, transmission level point (TLP), volume unit (vu), zero dBm transmission level point (0 dBm TLP)
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In a single-mode optical fiber, the rate of change of dispersion, with respect to wavelength, at the fiber's zero-dispersion wavelength. Note 1: In silica-based optical fibers, the zero-dispersion wavelength occurs at approximately 1.3
m, but this wavelength may be shifted toward the minimum-loss window by the addition of dopants to the fiber material during manufacture. Note 2: Doubly and quadruply clad single-mode fibers have two zero-dispersion points, and thus two zero-dispersion slopes.
- Browse Related Terms: first window, material dispersion coefficient [M(λ)], minimum-dispersion window, minimum-loss window, net loss, second window, silica, silicon dioxide (SiO2), spectral window, third window, zero-dispersion slope, zero-dispersion wavelength
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In a single-mode optical fiber, the wavelength or wavelengths at which material dispersion and waveguide dispersion cancel one another. Note: In all silica-based optical fibers, minimum material dispersion occurs naturally at a wavelength of approximately 1.3
m. Single-mode fibers may be made of silica-based glasses containing dopants that shift the material-dispersion wavelength, and thus, the zero-dispersion wavelength, toward the minimum-loss window at approximately 1.55
m. The engineering tradeoff is a slight increase in the minimum attenuation coefficient. 2. Loosely, in a multimode optical fiber, the wavelength at which material dispersion is minimum, i.e., essentially zero. Synonym minimum-dispersion wavelength.
- Browse Related Terms: first window, material dispersion coefficient [M(λ)], minimum-dispersion window, minimum-loss window, net loss, second window, silica, silicon dioxide (SiO2), spectral window, third window, zero-dispersion slope, zero-dispersion wavelength
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Synonym minimum-dispersion window.
- Browse Related Terms: chromatic dispersion, fiber dispersion, material dispersion, minimum-dispersion slope, minimum-dispersion wavelength, nonshifted fiber, optical dispersion, profile dispersion, waveguide dispersion, zero dispersion window
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See zero-bit insertion.
- Browse Related Terms: self-delineating block, Sentinel, zero insertion, zero stuffing, zero-bit insertion
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A decoder that yields an analog level of 0 dBm at its output when the input is the digital milliwatt signal. [47CFR] Note: The signal is a 1-kHz sine wave.
- Browse Related Terms: back-to-back connection, branching repeater, combinational logic element, common-mode rejection ratio (CMRR), equal-level patch bay, noise suppression, output rating, protection ratio, rated output power, receive-after-transmit time delay, receiver attack-time delay, sequential logic element, squelch, through-group equipment, vogad, zero-level decoder
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See zero-bit insertion.
- Browse Related Terms: self-delineating block, Sentinel, zero insertion, zero stuffing, zero-bit insertion
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The elimination of nonsignificant zeros from a numeral.
- Browse Related Terms: base, binary element, binary exponential backoff, binary notation, binary number, binary-coded decimal interchange code, bit, bit position, modulo-2 addition, parity check, pure binary numeration system, two-out-of-five code, zero suppression
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Synonym zero dBm transmission level point.
- Browse Related Terms: amplitude modulation equivalent (AME), average rate of transmission, batched communications, fading margin, frame frequency, resolution, sequential access, sequential transmission, system power margin, true power, zero transmission level point (0TLP)
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To fill unused storage locations in an information system (IS) with the representation of the character denoting "0". [INFOSEC-99]
- Browse Related Terms: browsing, clearing, COMSEC chip set, magnetic remanence, memory scavenging, no-lone zone, scavenging, zerofill
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To remove or eliminate the key from a crypto-equipment or fill device. [INFOSEC-99]
- Browse Related Terms: automatic remote rekeying, cold start, extraction resistance, manual remote rekeying, message indicator, permuter, Quadrant, remote rekeying, scratch pad store (SPS), single point keying, synchronous crypto-operation, unique key, zeroize
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Electronically stored data that have been degaussed, erased, or overwritten. [After X9.17]
- Browse Related Terms: contribution, PIN, post-production processing, sanitizing, zeroized
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In optical communications, a two-fiber cable consisting essentially of two single-fiber cables having their jackets conjoined by a strip of jacket material. Note 1: This name is borrowed from electrical terminology referring to lamp cord. As with lamp cord, optical zip-cord may be easily furcated by slitting or tearing the two jackets apart, permitting the installation of optical connectors. Note 2: Zip-cord cables include both loose-buffer and tight-buffer designs. [FAA]
- Browse Related Terms: aramid yarn, armor, braid, breakout cable, breakout kit, fiber buffer, fiber optic cable, fiber pigtail, flooding compound, pigtail, ribbon cable, rip cord, sheath, splice closure, strength member, tight buffer, zip-cord
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See communications zone, Fresnel zone, skip zone.
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The area surrounding a power station that is raised in potential above a remote or true grounding (earthing) point. [T1.318-2000]
- Browse Related Terms: address-indicating group (AIG), beacon, carrier sense, CARS, certificate user, communications network, communications reliability, contention, continuous operation, experimental station, fill-in area, master-slave timing, passive satellite, point-to-point transmission, primary distribution system, Private Networks, pulse-address multiple access (PAMA), relay station, remote clock, routing indicator (RI), slotted-ring network, station clock, station load, station-to-station basis, token passing, wireless terminal, zone of influence
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The space, adjacent to a lightning protection system, that is substantially immune to direct lightning strokes. [After T1.318-2000]
- Browse Related Terms: Asset, flaw, mutual suspicion, network trusted computing base (NTCB), password history, secure operating system, security flaw, trapdoor, trusted distribution, zone of protection