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Circuit Merit
The Circuit Merit system is a measurement process designed to assess the voice-to-noise ratio in wired and wireless telephone circuits, especially the Advanced Mobile Phone System, AMPS system, and although its reporting scale is sometimes used as input for calculating mean opinion score, the rating system is officially defined relative to given ranges of voice-to-noise ratios. Various technical sources state that experimental research vary in what ratio is required for good understanding, but is typically above 20 dB, and noticeably higher reports of voice quality can be achieved when the ratio is near 30 dB. There are 5 levels of quality, detailed as follows: Measurement of audio speech-to-noise ratios in a way which reflects interfering effects in a meaningful manner is difficult for the kinds of noise often encountered at mobile system receivers. For this reason and as a matter of convenience, a subjective rating of the interfering effect of the noise using the ter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Advanced Mobile Phone System
Advanced Mobile Phone System (AMPS) was an analog mobile phone system standard originally developed by Bell Labs and later modified in a cooperative effort between Bell Labs and Motorola. It was officially introduced in the Americas on October 13, 1983,Private Line and was deployed in many other countries too, including Israel in 1986, Australia in 1987, Singapore in 1988, and Pakistan in 1990. It was the primary analog mobile phone system in North America (and other locales) through the 1980s and into the 2000s. As of February 18, 2008, carriers in the United States were no longer required to support AMPS and companies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Absolute Category Rating
Absolute Category Rating (ACR) is a test method used in quality tests. The levels of the scale are, sorted by quality in decreasing order: * Excellent * Good * Fair * Poor * Bad In this method, a single test condition (generally an image or a video sequence) is presented to the viewers once only. They should then give a quality rating on an ACR scale. Test conditions should be presented in a random order per test person. The ACR scale is evaluated based on numbers that are assigned to the individual items, where ''Excellent'' equals to 5 and ''Bad'' equals to 1. The average numeric score over all experiment participants, for each test condition that was shown, is called the mean opinion score. The ACR scale is also used for telephony voice quality to give a mean opinion score. See also * Mean opinion score * Subjective video quality Subjective video quality is video quality as experienced by humans. It is concerned with how video is perceived by a viewer (also called "observ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal Strength And Readability Report
A signal strength and readability report is a standardized format for reporting the strength of the radio signal and the readability (quality) of the radiotelephone (voice) or radiotelegraph (Morse code) signal transmitted by another station as received at the reporting station's location and by their radio station equipment. These report formats are usually designed for only one communications mode or the other, although a few are used for both telegraph and voice communications. All but one of these signal report formats involve the transmission of numbers. History As the earliest radio communication used Morse code, all radio signal reporting formats until about the 1920s were for radiotelegraph, and the early voice radio signal report formats were based on the telegraph report formats. Timeline of signal report formats * The first signal report format code may have been QJS. * The U.S. Navy used R and K signals starting in 1929. * The QSK code was one of the twelve Q Code ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R-S-T System
The R-S-T system is used by amateur radio operators, shortwave listening, shortwave listeners, and other radio hobbyists to exchange information about the quality of a radio signal being received. The code is a three digit number, with one digit each for conveying an assessment of the signal's readability, strength, and tone. The code was developed in 1934 by Amateur radio operator Arthur W. Braaten, W2BSR, and was similar to that codified in the ITU Radio Regulations, Cairo, 1938. Readability The R stands for "Readability". Readability is a qualitative assessment of how easy or difficult it is to correctly copy the information being sent during the transmission (radio), transmission. In a Morse code telegraphy transmission, readability refers to how easy or difficult it is to distinguish each of the characters in the text of the message being sent; in a telephony, voice transmission, readability refers to how easy or difficult it is for each spoken word to be understood correc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
QSA And QRK Code
The QSA code and QRK code are interrelated and complementary signal reporting codes for use in wireless telegraphy (Morse code). An enhanced format, SINPO code, was published in the ITU Radio Regulations, Geneva, 1959, but is longer and unwieldy for use in the fast pace of Morse code communications. Current format The current definition of the QSA and QRK codes are officially defined in ITU Radio Regulations 1990, Appendix 13: Miscellaneous Abbreviations and Signals to Be Used in Radiotelegraphy Communications Except in the Maritime Mobile Service, and are also described identically in ACP131(F),: Historical development The QSK code is one of the earliest signal reporting formats and is a part of the Q code used for commercial radiotelegraph communication, appearing as one of the twelve Q Codes listed in the 1912 International Radiotelegraph Convention Regulations, and was later adopted by other radio services, especially amateur radio. The QSA code was mandated by the Madrid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perceptual Objective Listening Quality Analysis
Perceptual Objective Listening Quality Analysis (POLQA) was the working title of an ITU-T standard that covers a model to predict speech quality by means of analyzing digital speech signals. The model was standardized as Recommendation ITU-T P.863 (Perceptual objective listening quality assessment) in 2011. The second edition of the standard appeared in 2014, and the third, currently in-force edition was adopted in 2018 under the title Perceptual objective listening quality prediction. Measurement scope POLQA covers a model to predict speech quality,http://www.aes.org/e-lib/browse.cfm?elib=16829 Perceptual Objective Listening Quality Assessment (POLQA), The Third Generation ITU-T Standard for End-to-End Speech Quality Measurement Part I—Temporal Alignmenthttp://www.aes.org/e-lib/browse.cfm?elib=16830 Perceptual Objective Listening Quality Assessment (POLQA), The Third Generation ITU-T Standard for End-to-End Speech Quality Measurement Part II—Perceptual Model by means of digit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perceptual Evaluation Of Speech Quality
Perception () is the organization, identification, and interpretation of sensory information in order to represent and understand the presented information or environment. All perception involves signals that go through the nervous system, which in turn result from physical or chemical stimulation of the sensory system.Goldstein (2009) pp. 5–7 Vision involves light striking the retina of the eye; smell is mediated by odor molecules; and hearing involves pressure waves. Perception is not only the passive receipt of these signals, but it is also shaped by the recipient's learning, memory, expectation, and attention. Gregory, Richard. "Perception" in Gregory, Zangwill (1987) pp. 598–601. Sensory input is a process that transforms this low-level information to higher-level information (e.g., extracts shapes for object recognition). The process that follows connects a person's concepts and expectations (or knowledge), restorative and selective mechanisms (such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mean Opinion Score
Mean opinion score (MOS) is a measure used in the domain of Quality of Experience and telecommunications engineering, representing overall quality of a stimulus or system. It is the arithmetic mean over all individual "values on a predefined scale that a subject assigns to his opinion of the performance of a system quality". Such ratings are usually gathered in a subjective quality evaluation test, but they can also be algorithmically estimated. MOS is a commonly used measure for video, audio, and audiovisual quality evaluation, but not restricted to those modalities. ITU-T has defined several ways of referring to a MOS in RecommendatioITU-T P.800.1 depending on whether the score was obtained from audiovisual, conversational, listening, talking, or video quality tests. Rating scales and mathematical definition The MOS is expressed as a single rational number, typically in the range 1–5, where 1 is lowest perceived quality, and 5 is the highest perceived quality. Other MOS ranges ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plain Language Radio Checks
A plain-language radio check is the means of requesting and giving a signal strength and readability report for radiotelephony (voice) communications, and is the direct equivalent to the QSA and QRK code used to give the same report in radiotelegraph (Morse code) communications. SINPEMFO code is the voice signal reporting format developed by the ITU in 1959, but sees little use outside of shortwave listeners. Allied Communications Procedure 125(F), Communication Instructions Radiotelephone Procedure, published by the Combined Communication Electronics Board, defines radiotelephone procedures, and contains the original definitions for many common radio communications procedures, including Procedure Words, radio net operations, etc. Section 611 of ACP 125(F) details how to conduct radio checks using plain language. Radio check procedure The prowords listed below are for use when initiating and answering queries concerning signal strength and readability. Signal strength prowords ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mean Opinion Score
Mean opinion score (MOS) is a measure used in the domain of Quality of Experience and telecommunications engineering, representing overall quality of a stimulus or system. It is the arithmetic mean over all individual "values on a predefined scale that a subject assigns to his opinion of the performance of a system quality". Such ratings are usually gathered in a subjective quality evaluation test, but they can also be algorithmically estimated. MOS is a commonly used measure for video, audio, and audiovisual quality evaluation, but not restricted to those modalities. ITU-T has defined several ways of referring to a MOS in RecommendatioITU-T P.800.1 depending on whether the score was obtained from audiovisual, conversational, listening, talking, or video quality tests. Rating scales and mathematical definition The MOS is expressed as a single rational number, typically in the range 1–5, where 1 is lowest perceived quality, and 5 is the highest perceived quality. Other MOS ranges ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incident Command System
The Incident Command System (ICS) is a standardized approach to the command, control, and coordination of emergency response providing a common hierarchy within which responders from multiple agencies can be effective. ICS was initially developed to address problems of inter-agency responses to wildfires in California and Arizona but is now a component of the National Incident Management System (NIMS) in the US, where it has evolved into use in all-hazards situations, ranging from active shootings to hazmat scenes. In addition, ICS has acted as a pattern for similar approaches internationally. Overview ICS consists of a standard management hierarchy and procedures for managing temporary incident(s) of any size. ICS procedures should be pre-established and sanctioned by participating authorities, and personnel should be well-trained prior to an incident. ICS includes procedures to select and form temporary management hierarchies to control funds, personnel, facilities, equipmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Incident Management System
The National Incident Management System (NIMS) is a standardized approach to incident management developed by the United States Department of Homeland Security. The program was established in March 2004, in response to Homeland Security Presidential Directive-5, issued by President George W. Bush. It is intended to facilitate coordination between all responders (including all levels of government with public, private, and nongovernmental organizations). The system has been revised once, in December 2008. NIMS is the common framework that integrates a wide range of capabilities to help achieve objectives. NIMS defines multiple operational systems, including: * The Incident Command System * The Multiagency Coordination System * The Emergency operations center Background NIMS is the result of 40 years of work to improve interoperability in management of an incident. In the 1970s, different agencies at the local, state, and Federal levels got together and created FIRESCOPE, which i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
