omniomni/omni-engineering huggingface dataset:
Open systems architecture. Open systems architecture is a system design approach which aims to produce systems that are inherently interoperable and connectable without recourse to retrofit and redesign.

Concept
Systems design is a process of defining and engineering the architecture, methods, and interfaces necessary to accomplish a goal or fulfill a set of requirements. In open systems architecture, the design includes intentional provisions to make it possible to expand or modify the system at a later stage after initial operation. There is no one specific universal OSA, but it is essential the specific OSA applicable to a system is rigorously defined and documented. For example, in information technology and telecommunication, such design principles lead to open systems.

Telecommunications
In telecommunications, open systems architecture (OSA) is a standard that describes the layered hierarchical structure, configuration, or model of a communications or distributed data processing system. It enables system description, design, development, installation, operation, improvement, and maintenance to be performed at the abstraction layers in the hierarchical structure. Each layer provides a set of accessible functions that can be controlled and used by the functions in the layer above it. Each layer can be implemented without affecting the implementation of other layers.  The alteration of system performance by the modification of one or more layers may be accomplished without altering the existing equipment, procedures, and protocols at the remaining layers.

Examples of independent alterations include the conversion from wire to optical fiber at a physical layer without affecting the data link layer or the network layer, except to provide more traffic capacity, and the altering of the operational protocols at the network level without altering the physical layer.

See also 
Hardware Open Systems Technologies
Architecture of Interoperable Information Systems
Architectural pattern
Enterprise architecture
OSI model
Open-system environment reference model

References

Sources
 
 
 
     

Telecommunications standards
Systems architecture
Overflow. Overflow may refer to:

Computing and telecommunications
Integer overflow, a condition that occurs when an integer calculation produces a result that is greater than what a given register can store or represent
Buffer overflow, a situation whereby the incoming data size exceeds that which can be accommodated by a buffer.
Heap overflow, a type of buffer overflow that occurs in the heap data area
Overflow (software), a NASA-developed computational fluid dynamics program using overset (Chimera) grids
Overflow condition, a situation that occurs when more information is being transmitted than the hardware can handle
Overspill, a proof technique in non-standard analysis, is less commonly called overflow
Stack overflow in which a computer program makes too many subroutine calls and its call stack runs out of space

Other
Overflow (company), a Japanese video game developer
Overflow (magazine), a free quarterly in Brooklyn, New York, US
River overflow, a relatively long and significant increase in the water content of a river, causing a rise in its level
Sanitary sewer overflow, a condition whereby untreated sewage is discharged into the environment, escaping wastewater treatment
"Overflow", a 2024 song by Linkin Park from the album From Zero
Title 47 CFR Part 68. Title 47 CFR Part 68 is a section of the Code of Federal Regulations of the United States that regulates the direct electrical connection of telecommunications equipment and customer premises wiring with the public switched telephone network, certain private line services, and connection of private branch exchange (PBX) equipment to certain telecommunication interfaces.

Scope
The direct connection of telecommunications equipment and customer premises wiring with the public switched telephone network and certain private line services, such as
foreign exchange lines at the customer premises end
the station end of off-premises stations associated with PBX and Centrex services
trunk-to-station tie lines at the trunk end only
switched service network station lines, i.e., common control switching arrangements
The direct connection of
all PBX and similar systems to private line services for tie trunk type interfaces,
off-premises station lines, and (3) automatic identified outward dialing (AIOD) and message registration. 

Part 68 rules provide the technical and procedural standards under which direct electrical connection of customer-provided telephone equipment, systems, and protective apparatus may be made to the nationwide network without causing harm and without a requirement for protective circuit arrangements in the service-provider networks.

The equivalent European regulation is called TBR21.

References

 FCC 47 CFR Part 68 section 68.502 superseded by T1.TR5-1999
 Title 47 CFR Part 68

External links
ACTA documents
T1.TR5-1999

Local loop
United States communications regulation
Code of Federal Regulations
Path profile. In telecommunications, a path profile is a graphic representation of the physical features of a propagation path in the vertical plane containing both endpoints of the path, showing the surface of the Earth and including trees, buildings, and other features that may obstruct the radio signal.  

Profiles are drawn either with an effective Earth radius simulated by a parabolic arc--in which case the ray paths are drawn as straight lines--or with a "flat Earth"-- in which case the ray paths are drawn as parabolic arcs.

References

Radio frequency propagation
Penetration. Penetration may refer to:

Science and technology
 Passage through a partition or wall by a wire, cable, or other electrically conductive object
 Penetration (firestop), an opening in a wall or floor assembly required to have a fire-resistance rating, for the purpose of accommodating the passage of a mechanical, electrical, or structural penetrant
 Penetration (weapons), the ability to pierce the target's armor or other protection
 Penetration depth of light or any electromagnetic radiation in a physical medium
 Penetrating trauma, injury that occurs when an object pierces the skin and enters a tissue of the body
 In roofing, pipes, conduits, and HVAC supports passing through the room
 An unauthorized act of bypassing access control

Arts and media
 Penetration (band), a punk rock band
 "Penetration", a song on Iggy and the Stooges' album Raw Power
 "Penetration", a song on Pedro the Lion's album Control
 "Penetration", a song by The Pyramids
 Body of Lies (film), a film formerly known as Penetration

Other uses
 Penetration (warfare), the breaching of, and moving past, a defensive military line
 Market penetration or brand penetration, the degree to which a product or service is known and/or used
 Sexual penetration, or sexual intercourse
 in some jurisdictions, a criminal charge related to various sexual offences
 In basketball, the ability of a player to drive through the opposition's defense
 In magic, an illusion in which one object appears to pass through another

See also 
 Penetrator (disambiguation)
 Interpenetration (disambiguation)
Personal mobility. In Universal Personal Telecommunications (UPT), personal mobility is the ability of a user to access telecommunication services at any UPT terminal on the basis of a personal identifier, and the capability of the network to provide those services in accord with the user's service profile. 

Personal mobility involves the network's capability to locate the terminal associated with the user for the purposes of addressing, routing, and charging the user for calls. "Access" is intended to convey the concepts of both originating and terminating services. Management of the service profile by the user is not part of personal mobility. The personal mobility aspects of personal communications are based on the UPT number.

References 

Telephone numbers
Photocurrent. Photocurrent is the electric current through a photosensitive device, such as a photodiode, as the result of exposure to radiant power.  The photocurrent may occur as a result of the photoelectric, photoemissive, or photovoltaic effect.  The photocurrent may be enhanced by internal gain caused by interaction among ions and photons under the influence of applied fields, such as occurs in an avalanche photodiode (APD).

When a suitable radiation is used, the photoelectric current is directly proportional to intensity of radiation and increases with the increase in accelerating potential till the stage is reached when photo-current becomes maximum and does not increase with further increase in accelerating potential. The highest (maximum) value of the photo-current is called saturation current. The value of retarding potential at which photo-current becomes zero is called cut-off voltage or stopping potential for the given frequency of the incident ray.

Photovoltaics

The generation of a photocurrent forms the basis of the photovoltaic cell.

Photocurrent spectroscopy
A characterization technique called photocurrent spectroscopy (PCS), also known as photoconductivity spectroscopy, is widely used for studying optoelectronic properties of semiconductors and other light absorbing materials.  The setup of the technique involves having a semiconductor contacted with electrodes allowing for application of an electric bias, while at the same time a tunable light source incident with a given specific wavelength (energy) and power, usually pulsed by a mechanical chopper.  

The quantity measured is the electrical response of the circuit, coupled with the spectrograph obtained by varying the incident light energy by a monochromator.  The circuit and optics are coupled by use of a lock-in amplifier. The measurements give information related to the band gap of the semiconductor, allowing for identification of various charge transitions like exciton and trion energies. This is highly relevant for studying semiconductor nanostructures like quantum wells, and other nanomaterials like transition metal dichalcogenide monolayers.

Furthermore, by using a piezo stage to vary the lateral position of the semiconductor with micron precision, one can generate a micrograph false color image of the spectra for different positions.  This is called scanning photocurrent microscopy (SPCM).

See also
 Photoconductivity
 Transient photocurrent (TPC)

References

 

Electromagnetism
Polarential telegraph system. A polarential telegraph system is a direct-current telegraph system employing polar transmission in one direction and a form of differential duplex transmission in the other. 

Two types of polarential systems, known as types A and B, are in use. In half-duplex operation of a type A polarential system, the direct-current balance is independent of line resistance. In half-duplex operation of a type B polarential system, the direct current is substantially independent of the line leakage. Type A is better for cable loops where leakage is negligible but resistance varies with temperature. Type B is considered better for open wire where variable line leakage is frequent.

See also

 Neutral direct-current telegraph system

References

Telegraphy
Power-law index profile. For optical fibers, a power-law index profile is an index of refraction profile characterized by 

where

and  is the nominal refractive index as a function of distance from the fiber axis,  is the nominal refractive index on axis,  is the refractive index of the cladding, which is taken to be homogeneous (),  is the core radius, and  is a parameter that defines the shape of the profile.  is often used in place of . Hence, this is sometimes called an alpha profile. 

For this class of profiles, multimode distortion is smallest when  takes a particular value depending on the material used. For most materials, this optimum value is approximately 2. In the limit of infinite , the profile becomes a step-index profile.

See also
Graded-index fiber

References

Fiber optics
Power margin. In telecommunications, the power margin is the difference between available signal power and the minimum signal power needed to overcome system losses and still satisfy the minimum input requirements of the receiver for a given performance level. 

System power margin reflects the excess signal level, present at the input of the receiver, that is available to compensate for (a) the effects of component aging in the transmitter, receiver, or physical transmission medium, and (b) a deterioration in propagation conditions. Synonym system power margin.

References

Telecommunications engineering
Protocol-control information. In telecommunications, the term protocol-control information (PCI) has the following meanings:

  The queries and replies among communications equipment to determine the respective capabilities of each end of the communications link. 
  For layered systems, information exchanged between entities of a given layer, via the service provided by the next lower layer, to coordinate their joint operation.

References

 
Reference models
Telecommunications standards
ISO standards
ITU-T recommendations
ITU-T X Series Recommendations
Psophometric voltage. Psophometric voltage is a circuit noise voltage measured with a psophometer that includes a CCIF-1951 weighting network.

"Psophometric voltage" should not be confused with "psophometric emf," i.e., the emf in a generator or line with 600 Ω internal resistance. For practical purposes, the psophometric emf is twice the corresponding psophometric voltage.

Psophometric voltage readings, V, in millivolts, are commonly converted to dBm(psoph) by dBm(psoph) = 20 log10V – 57.78.

References

Electrical parameters
Noise (electronics)
Telecommunications engineering
Quasi-analog signal. In telecommunications, a quasi-analog signal is a digital signal that has been converted to a form suitable for transmission over a specified analog channel.  

The specification of the analog channel should include frequency range, bandwidth, signal-to-noise ratio, and envelope delay distortion. When quasi-analog form of signaling is used to convey message traffic over dial-up telephone systems, it is often referred to as voice-data. A modem may be used for the conversion process.

References

Signal processing
Random number. A random number is generated by a random (stochastic) process such as throwing Dice. Individual numbers can't be predicted, but the likely result of generating a large quantity of numbers can be predicted by specific mathematical series and statistics.

Algorithms and implementations
Random numbers are frequently used in algorithms such as Knuth's 1964-developed algorithm for shuffling lists. (popularly known as the Knuth shuffle or the Fisher–Yates shuffle, based on work they did in 1938).

In 1999, a new feature was added to the Pentium III: a hardware-based random number generator. It has been described as "several oscillators combine their outputs and that odd waveform is sampled asynchronously." These numbers, however, were only 32 bit, at a time when export controls were on 56 bits and higher, so they were not state of the art.

Common understanding
In common understanding, "1 2 3 4 5" is not as random as "3 5 2 1 4" and certainly not as random as "47 88 1 32 41" but "we can't say authoritavely that the first sequence is not random ... it could have been generated by chance."

When a police officer claims to have done a "random .. door-to-door" search, there is a certain expectation that members of a jury will have.

Real world consequences
Flaws in randomness have real-world consequences.

A 99.8% randomness was shown by researchers to negatively affect an estimated 27,000 customers of a large service and that the problem was not limited to just that situation.

See also
 Algorithmically random sequence
 Quasi-random sequence
 Random number generation
 Random sequence
 Random variable
 Random variate
 Random real

References

Permutations
Received noise power. In telecommunications, received noise power is a measure of noise in a receiver. For example, the received noise power might be:
The calculated or measured noise power, within the bandwidth being used, at the receive end of a circuit, channel, link, or system.
The absolute power of the noise measured or calculated at a receive point. The related bandwidth and the noise weighting must also be specified.
The value of noise power, from all sources, measured at the line terminals of a telephone set's receiver.' Either flat weighting or some other specific amplitude-frequency characteristic or noise weighting characteristic must be associated with the measurement.

Telecommunication theory
Noise (electronics)
Attack-time delay. In telecommunications, attack-time delay is the time needed for a receiver or transmitter to respond to an incoming signal.

For a receiver, the attack-time delay is defined as the time interval from the instant a step radio-frequency signal, at a level equal to the receiver's threshold of sensitivity, is applied to the receiver input, to the instant when the receiver's output amplitude reaches 90% of its steady-state value. If a squelch circuit is operating, the receiver attack-time delay includes the time for the receiver to break squelch. 

For a transmitter, the attack-time delay is defined as the interval from the instant the transmitter is keyed-on to the instant the transmitted radio-frequency signal amplitude has increased to a specified level, usually 90% of its key-on steady-state value.  The transmitter attack-time delay excludes the time required for automatic antenna tuning.

See also
Transmit-after-receive time delay
Receive-after-transmit time delay

References

Telecommunications engineering
Radio technology
Recovery procedure. In telecommunications, a recovery procedure is a process that attempts to bring a system back to a normal operating state. Examples:
The actions necessary to restore an automated information system's data files and computational capability after a system failure. 
In data communications, a process whereby a data station attempts to resolve conflicting or erroneous conditions arising during the data transfer.

See also
Error detection and correction
Fault-tolerant design
Fault-tolerant system

References

Telecommunications techniques
Fault tolerance
Reference circuit. A reference circuit is a hypothetical electric circuit of specified equivalent length and configuration, and having a defined transmission characteristic or characteristics, used primarily as a reference for measuring the performance of other, i.e., real, circuits or as a guide for planning and engineering of circuits and networks.  

Normally, several types of reference circuits are defined, with different configurations, because communications are required over a wide range of distances. Another type of reference circuit shows how to configure integrated circuits into function blocks, which Analog Devices provides for electrical design engineers.  Analog Devices' Circuits from the Lab reference circuits are fully tested and come with the schematics, evaluation boards, and device drivers necessary for system integration.  A group of related reference circuits is also called a reference system.

References

See also
 netlist 
 SPICE

Electronic circuits
Reference noise. In telecommunications, reference noise is the magnitude of circuit noise chosen as a reference for measurement.  

Many different levels with a number of different weightings are in current use, and care must be taken to ensure that the proper parameters are stated. 

Specific ones include: dBa, dBa(F1A), dBa(HA1), dBa0, dBm, dBm(psoph), dBm0, dBrn, dBrnC, dBrnC0, dBrn(f1-f2), dBrn(144-line), dBx.

References

Noise (electronics)
Communication circuits
Telecommunications techniques
Reference surface. In fiber optic technology, a reference surface is that surface of an optical fiber that is used to contact the transverse-alignment elements of a component such as a connector or mechanical splice.  For telecommunications-grade fibers, the reference surface is the outer surface of the cladding. For plastic-clad silica (PCS) fibers, which have a strippable polymer cladding (not to be confused with the polymer overcoat of an all-silica fiber), the reference surface may be the core.

References

Fiber optics
Reliability. Reliability, reliable, or unreliable may refer to:

Science, technology, and mathematics

Computing
 Data reliability (disambiguation), a property of some disk arrays in computer storage
 Reliability (computer networking), a category used to describe protocols
 Reliability (semiconductor), outline of semiconductor device reliability drivers

Other uses in science, technology, and mathematics
 Reliability (statistics), the overall consistency of a measure
 Reliability engineering, concerned with the ability of a system or component to perform its required functions under stated conditions for a specified time
 Human reliability in engineered systems
 Reliability theory, as a theoretical concept, to explain biological aging and species longevity

Other uses
 Reliabilism, in philosophy and epistemology
 Unreliable narrator, whose credibility has been seriously compromised

See also
 
 
 
 Reliant (disambiguation)
Remote Operations Service Element protocol. The Remote Operations Service Element (ROSE) is the OSI service interface, specified in ITU-T Recommendation X.219, ISO/IEC International Standard 9072-1, that (a) provides remote operation capabilities, (b) allows interaction between entities in a distributed application, and (c) upon receiving a remote operations service request, allows the receiving entity to attempt the operation and report the results of the attempt to the requesting entity. 

OSI application protocols such as X.400 and X.500 use the services provided by ROSE. The ROSE protocol itself is defined using the notation of ASN.1.

References

International Telecommunication Union Recommendation X.219 
International Telecommunication Union Recommendation X.229 
ISO ISO 9072

See also 
Remote procedure call
Abstract Syntax Notation One
Transaction Capabilities Application Part

ITU-T recommendations
Repeating coil. In telecommunications, a repeating coil is a voice-frequency transformer characterized by a closed magnetic core, a pair of identical balanced primary (line) windings, a pair of identical but not necessarily balanced secondary (drop) windings, and low transmission loss at voice frequencies.   It permits transfer of voice currents from one winding to another by magnetic induction, matches line and drop impedances, and prevents direct conduction between the line and the drop.

It is a special application of an isolation transformer, and is often used to prevent ground loops or earth loops, which cause humming or buzzing in audio circuits.  It also prevents low direct current voltages from passing.

References

Electromagnetic coils
Telephony equipment
Electric transformers