User-oriented measures of telecommunication quality
TL;DR: The authors discuss in particular call processing, data communication quality, video and voice quality measures, which will be used by providers to design and implement telecommunication systems and services, and by users to define telecommunication requirements and select the products that most effectively meet them.
Abstract: With the deregulation and emergence of new telecommunication providers in many countries, national and international standards committees have assumed increased responsibility for the cooperative planning of new technology development and the matching of multivendor service offerings with user needs. One important focus of this effort has been the standardization of user-oriented, technology-independent measures of telecommunication service quality. The standardized measures will be used by providers to design and implement telecommunication systems and services, and by users to define telecommunication requirements and select the products that most effectively meet them. The authors discuss in particular call processing, data communication quality, video and voice quality measures. >
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TL;DR: These objective metrics have a number of interesting properties, including utilization of spatial activity filters which emphasize long edges on the order of 10 arc min while simultaneously performing large amounts of noise suppression and simple perceptibility thresholds and spatial-temporal masking functions.
Abstract: Many organizations have focused on developing digital video quality metrics which produce results that accurately emulate subjective responses. However, to be widely applicable a metric must also work over a wide range of quality, and be useful for in-service quality monitoring. The Institute for Telecommunication Sciences (ITS) has developed spatial-temporal distortion metrics that meet all of these requirements. These objective metrics are described in detail and have a number of interesting properties, including utilization of 1) spatial activity filters which emphasize long edges on the order of 1/5 degree while simultaneously performing large amounts of noise suppression, 2) the angular direction of the spatial gradient, 3) spatial-temporal compression factors of at least 384:1 (spatial compression of at least 64:1 and temporal compression of at least 6:1, and 4) simple perceptibility thresholds and spatial-temporal masking functions. Results are presented that compare the objective metric values with mean opinion scores from a wide range of subjective data bases spanning many different scenes, systems, bit-rates, and applications.
187 citations
Cites background from "User-oriented measures of telecommu..."
...01-1995 15 and included scenes from 5 categories: (1) one person, mainly head and shoulders, (2) one person with graphics and/or more detail, (3) more than one person, (4) graphics with pointing, and (5) high object and/or camera motion....
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16 Apr 2002
TL;DR: This paper establishes first guidelines to perform subjective assessment of game quality in 3G mobile networks, and an experimental study is conducted to assess the game quality of a multiplayer real-time game, XBlast, for different network conditions.
Abstract: Mean Opinion Score (MOS) tests are a well-known procedure to indicate the suitability of telecommunications equipment to provide voice services. However, converged data networks provide a variety of services, increasingly entertainment services as e.g. games. After describing the potential of games for Third Generation (3G) mobile networks, this paper establishes first guidelines to perform subjective assessment of game quality. Subsequently, an experimental study is conducted to assess the game quality of a multiplayer real-time game, XBlast, for different network conditions.
50 citations
Additional excerpts
...[9]) and multimedia application’s quality ([10], [11], [12])....
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25 Apr 2011
TL;DR: This paper presents an overview of some existing techniques of Quality of Service QoS and Quality of Experience QoE, which defines the quality perceived by the user and is assessed at the terminal level.
Abstract: This paper presents an overview of some existing techniques of Quality of Service QoS and Quality of Experience QoE. QoS stands for the quality of the network in terms of transporting data with a minimum of delay and packet loss and a maximum of bandwidth. The extremum values depend surely of the provided service. QoE defines the quality perceived by the user and is assessed at the terminal level. It can be computed through objective and subjective ways. A comparison of the two techniques as well as an improvement of the service by combining them are also addressed.
36 citations
Cites background from "User-oriented measures of telecommu..."
...3) Problems detection: Disregarding the human factors aforementioned, various factors contribute to the determination of the QoE in an experiment as perceived by the user [32], [33], [34]:...
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TL;DR: A novel high-quality, low-complexity dual-rate 4.7 and 6.5 kbits/s algebraic code excited linear predictive codec is proposed for adaptive multi-mode speech communicators, which can drop their source rate and speech quality under network control in order to invoke a more error resilient modem amongst less favorable channel conditions.
Abstract: A novel high-quality, low-complexity dual-rate 4.7 and 6.5 kbits/s algebraic code excited linear predictive codec is proposed for adaptive multi-mode speech communicators, which can drop their source rate and speech quality under network control in order to invoke a more error resilient modem amongst less favorable channel conditions. Source-matched binary Bose-Chaudhuri-Hocquenghem (BCH) codecs combined with unequal protection diversity- and pilot-assisted 16and 64-level quadrature amplitude modulation (16-QAM, 64-QAM) are employed in order to accommodate both the 4.7 and the 6.5 kbits/s coded speech bits at a signaling rate of 3.1 kBd. Assuming an excess bandwidth of 100%, in a bandwidth of 200 kHz 32 time slots can be created, which allows us to support in excess of 50 users, when employing packet reservation multiple access (PRMA). Good communications quality speech is delivered in an equivalent bandwidth of 4 kHz, if the channel signal-to-noise ratio (SNR) and signal-to-interference ratio (SIR) of the benign indoors cordless channel are in excess of about 15 and 25 dB for the lower and higher speech quality 16-QAM and 64-QAM systems, respectively, and the PRMA time-slots are sufficiently uninterfered due to using time-slot classification algorithms and due to the attenuation of partitioning walls and ceilings. >
31 citations
TL;DR: The preliminary results of two attempts at correlation between a set of objective measurements and subjective assessment carried out on a number of images under varying compression systems are presented.
Abstract: The Research Centre of RAI (Radiotelevisione Italiana) is developing studies to find a correlation between objective measurements of video impairments and human perception. Such measurements should allow subjective assessments without human input. This paper presents the preliminary results of two attempts at correlation between a set of objective measurements and subjective assessment carried out on a number of images under varying compression systems.
18 citations
References
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TL;DR: A perceptually motivated objective measure for evaluating speech quality is presented and exhibits statistically a monotonic relationship with the mean opinion score, a widely used criterion for speech coder assessment.
Abstract: A perceptually motivated objective measure for evaluating speech quality is presented. The measure, computed from the original and coded versions of an utterance, exhibits statistically a monotonic relationship with the mean opinion score, a widely used criterion for speech coder assessment. For each 10-ms segment of an utterance, a weighted spectral vector is computed via 15 critical band filters for telephone bandwidth speech. The overall distortion, called Bark spectral distortion (BSD), is the average squared Euclidean distance between spectral vectors of the original and coded utterances. The BSD takes into account auditory frequency warping, critical band integration, amplitude sensitivity variations with frequency, and subjective loudness. >
384 citations
"User-oriented measures of telecommu..." refers methods in this paper
...In one study, a filter bank much like that described in Figure 7 was used to perceptually transform the input to and output from a voice system under test [33]....
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08 Sep 1993
TL;DR: A perception-based model that predicts subjective ratings from these objective measurements, and a demonstration of the correlation between the model's predictions and viewer panel ratings are presented.
Abstract: The Institute for Telecommunication Sciences (ITS) has developed an objective video quality assessment system that emulates human perception. The system returns results that agree closely with quality judgements made by a large panel of viewers. Such a system is valuable because it provides broadcasters, video engineers and standards organizations with the capability for making meaningful video quality evaluations without convening viewer panels. The issue is timely because compressed digital video systems present new quality measurement questions that are largely unanswered.
The perception-based system was developed and tested for a broad range of scenes and video technologies. The 36 test scenes contained widely varying amounts of spatial and temporal information. The 27 impairments included digital video compression systems operating at line rates from 56 kbits/sec to 45 Mbits/sec with controlled error rates, NTSC encode/decode cycles, VHS and S-VHS record/play cycles, and VHF transmission. Subjective viewer ratings of the video quality were gathered in the ITS subjective viewing laboratory that conforms to CCIR Recommendation 500-3. Objective measures of video quality were extracted from the digitally sampled video. These objective measurements are designed to quantify the spatial and temporal distortions perceived by the viewer.
This paper presents the following: a detailed description of several of the best ITS objective measurements, a perception-based model that predicts subjective ratings from these objective measurements, and a demonstration of the correlation between the model's predictions and viewer panel ratings. A personal computer-based system is being developed that will implement these objective video quality measurements in real time. These video quality measures are being considered for inclusion in the Digital Video Teleconferencing Performance Standard by the American National Standards Institute (ANSI) Accredited Standards Committee T1, Working Group T1A1.5.
286 citations
TL;DR: An LPC (linear predictive coding) cepstrum distance measure (CD) is introduced as an objective measure for estimating the subjective quality of speech signals and good correspondence between LPC CD and the subjectivequality, expressed in terms of both opinion equivalent Q and mean opinion score are shown.
Abstract: An LPC (linear predictive coding) cepstrum distance measure (CD) is introduced as an objective measure for estimating the subjective quality of speech signals. Good correspondence between LPC CD and the subjective quality, expressed in terms of both opinion equivalent Q and mean opinion score, are shown. Good repeatability of objective quality evaluation using LPC CD is also shown. A method for generating an artificial voice signal that reflects the characteristics of real speech signals is described. The LPC CD values calculated using this artificial voice are almost the same as those calculated using real speech signals. The speaker-dependency of the coded-speech quality is shown to be an important factor in low-bit-rate speech coding. Even taking this factor into consideration, LPC CD is shown to be effective for estimating the subjective quality. >
151 citations
"User-oriented measures of telecommu..." refers background in this paper
...For waveform coders operating over digital channels with relatively few bit errors, an objective measurement called segmental signal-to-noise ratio (SNR) is useful [29]....
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68 citations
"User-oriented measures of telecommu..." refers methods in this paper
...Standard industry procedures have been used for the collection of the subjective viewing responses [28]....
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TL;DR: A framework was developed to help assess communications service quality in a manner that most closely reflects the broad array of performance parameters experienced by customers, adding to the thoroughness with which service providers and customers alike assess the quality of communications services.
Abstract: A framework is described that was developed to help assess communications service quality in a manner that most closely reflects the broad array of performance parameters experienced by customers. Examples of its application are presented. An additional benefit experienced with the use of this framework is a more consistent, disciplined analysis of service parameters, adding to the thoroughness with which service providers and customers alike assess the quality of communications services. >
37 citations