Objective Mean Opinion Score Research Articles

QoE-Aware Network Pricing, Power Allocation, and Admission Control

In wireless communications, focusing on end-user satisfaction and maximizing network operators' revenue are emerging business challenges. In this paper, we investigate the price-based power allocation problem where, first, base stations (BSs) set prices by maximizing users' utility modeled by their mean opinion score (MOS). Then, each user's optimal power is set by maximizing operator revenue while ensuring the minimum data rate for each user. We propose a hybrid MOS-based pricing method to model users' utility instead of the conventional achievable rate approach. Our hybrid approach applies a machine learning algorithm to model the MOS of the call service in terms of the received signal strength indicator (RSSI). In terms of MOS and outage probability, our proposed method outperforms the rate-based pricing method and the conventional objective MOS models. In addition, we consider a joint admission control and price-based power allocation problem. When a new user requests to connect, a central controller determines whether or not to accept the new connection based on the system's MOS and average outage probability. The results demonstrate a trade-off between the number of users admitted and their level of satisfaction, providing operators with crucial knowledge about how to use their network resources more effectively.

Développer l’ACT face à la douleur chronique. L’efficience : un nouvel argument en faveur du changement ?

The human auditory system is modeled by different auditory models representing the distribution of speech sound energy in different channels across the cochlea using filter-banks of different bandwidths. In previous algorithms of non-intrusive speech quality evaluation, auditory features are determined using these auditory models on per frame basis and then averaged over the entire speech utterance. In these approaches, the effect of impulsive noise and other non-stationary noise effects get averaged over the utterance. To include the variations in the features of speech over time in the speech utterance, a multiple time-scale features approach has been proposed as the speech features vary from frame to frame that accounts for variation of noise characteristics over the speech utterance and thus its affect on quality mapping. In this work, non-intrusive speech quality evaluation has been done as an optimal linear combination of quality mapping called objective mean opinion score (MOS), computed using multiple time-scale estimates of features. The objective MOS of each of the multiple time-scale estimates (the combination of multiple active speeches) are obtained using a probabilistic approach. The overall objective MOS of the speech utterance is computed by taking the optimal linear combination of the estimated objective MOS using multiple time-scale estimates of features, where the optimality is based on the minimum mean square error (MMSE) criterion or correlation maximization criterion. The results are given in terms of Pearson's correlation coefficient and root mean square error (RMSE) between the subjective MOS and the estimated overall objective MOS for three different standard databases. The results have been compared with a single time-scale features approach, the ITU-T Recommendation P.563 and recent algorithms.

Non-intrusive speech quality estimation as combination of estimates using multiple time-scale auditory features

The human auditory system is modeled by different auditory models representing the distribution of speech sound energy in different channels across the cochlea using filter-banks of different bandwidths. In previous algorithms of non-intrusive speech quality evaluation, auditory features are determined using these auditory models on per frame basis and then averaged over the entire speech utterance. In these approaches, the effect of impulsive noise and other non-stationary noise effects get averaged over the utterance. To include the variations in the features of speech over time in the speech utterance, a multiple time-scale features approach has been proposed as the speech features vary from frame to frame that accounts for variation of noise characteristics over the speech utterance and thus its affect on quality mapping. In this work, non-intrusive speech quality evaluation has been done as an optimal linear combination of quality mapping called objective mean opinion score (MOS), computed using multiple time-scale estimates of features. The objective MOS of each of the multiple time-scale estimates (the combination of multiple active speeches) are obtained using a probabilistic approach. The overall objective MOS of the speech utterance is computed by taking the optimal linear combination of the estimated objective MOS using multiple time-scale estimates of features, where the optimality is based on the minimum mean square error (MMSE) criterion or correlation maximization criterion. The results are given in terms of Pearson's correlation coefficient and root mean square error (RMSE) between the subjective MOS and the estimated overall objective MOS for three different standard databases. The results have been compared with a single time-scale features approach, the ITU-T Recommendation P.563 and recent algorithms.

Packet loss visibility across SD, HD, 3D, and UHD video streams

The trend towards video streaming with increased spatial resolutions and dimensions, SD, HD, 3D, and 4kUHD, even for portable devices has important implications for displayed video quality. There is an interplay between packetization, packet loss visibility, choice of codec, and viewing conditions, which implies that prior studies at lower resolutions may not be as relevant. This paper presents two sets of experiments, the one at a Variable BitRate (VBR) and the other at a Constant BitRate (CBR), which highlight different aspects of the interpretation. The latter experiments also compare and contrast encoding with either an H.264 or an High Efficiency Video Coding (HEVC) codec, with all results recorded as objective Mean Opinion Score (MOS). The video quality assessments will be of interest to those considering: the bitrates and expected quality in error-prone environments; or, in fact, whether to use a reliable transport protocol to prevent all errors, at a cost in jitter and latency, rather than tolerate low levels of packet errors.

Non‐intrusive speech quality assessment using multi‐resolution auditory model features for degraded narrowband speech

A multi-resolution framework using auditory perception-based wavelet packet transform is invoked in multi-resolution auditory model (MRAM) and used for non-intrusive objective speech quality estimation. The MRAM provides a detailed time-frequency modelling of the human auditory system compared to earlier models that have been used for non-intrusive speech quality estimation. The objective Mean Opinion Score (MOS) of a degraded narrowband speech utterance has been estimated by Gaussian Mixture Model (GMM) probabilistic approach using MRAM-based feature vector. Additionally, a recent auditory model (Lyons’ auditory model) based features, mel-frequency cepstral coefficients (MFCC), and line spectral frequencies (LSF) features have also been used independently for comparison of the performance of MRAM features. The combination of MFCC and LSF features with MRAM features for non-intrusive speech quality estimation using GMM probabilistic approach has been proposed and investigated. The performance of these feature vectors has been evaluated and compared with ITU-T Recommendation P.563 and a recent published work by computing correlation coefficient and root-mean-square error between the subjective MOS and the estimated objective MOS. It is found that the proposed method that uses a combination of MRAM features, MFCC, and LSF feature vectors for non-intrusive speech quality performs better than both the other algorithms.

Mean opinion score (MOS) revisited: methods and applications, limitations and alternatives

Mean opinion score (MOS) has become a very popular indicator of perceived media quality. While there is a clear benefit to such a "reference quality indicator" and its widespread acceptance, MOS is often applied without sufficient consideration of its scope or limitations. In this paper, we critically examine MOS and the various ways it is being used today. We highlight common issues with both subjective and objective MOS and discuss a variety of alternative approaches that have been proposed for media quality measurement.

Subjective and Objective MOS Evaluation of User’s Perceived Quality Assessment for IPTV Service: a Study of the Experimental Investigations

The digital television providing over the networks, based on the Internet Protocol, gives the exceptional opportunities to the service provider for its broadcasting. However, all Internet Protocol Television broadcasting solutions are directly related with the user’s perception of the service quality. This perception depends on the visible or audible factors, which are observed during the channel change process of Internet Protocol Television. The channel change process of Internet Protocol Television is assessed by its duration. Due to this, it is important to analyze the relation between the channel change process and the user’s perception of the quality of Internet Protocol Television. The experimental investigations for the subjective and objective Mean Opinion Score evaluation of the user’s perceived quality assessment for Internet Protocol Television according to the channel change process are presented.DOI: http://dx.doi.org/10.5755/j01.eee.19.7.5178

A Multiresolution Model of Auditory Excitation Pattern and Its Application to Objective Evaluation of Perceived Speech Quality

This paper proposes a multiresolution model of auditory excitation pattern and applies it to the problem of objective evaluation of subjective wideband speech quality. The model uses wavelet packet transform for time-frequency decomposition of the input signal. The selection of the wavelet packet tree is based on an optimality criterion formulated to minimize a cost function based on the critical band structure. The models of the different auditory phenomena are reformulated for the multiresolution framework. This includes the proposition of duration dependent outer and middle ear weighting, multiresolution spectral spreading, and multiresolution temporal smearing. As an application, the excitation pattern is used to define an objective measure of auditory distortion of a distorted speech signal compared to the undistorted one. The performance of this objective measure is evaluated with a database of various kinds of NOISEX-92 degraded wideband speech signals in predicting the subjective mean opinion score (MOS) and is compared with the fast Fourier transform (FFT)-based ITU-T PESQ P.862.2 algorithm. The proposed measure is found to achieve comparable correlation between subjective MOS and objective MOS as PESQ P.862.2, with a trend suggesting better correlation for the nonstationary degradations compared to the stationary ones. Further refinement of the measure for distortion types other than additive noise is anticipated

잡음 패턴의 지능적 추정을 통한 음질 개선 알고리즘

In this paper, we propose an algorithm that improves a tone quality of a noisy audio signal in order to enhance a performance of perceptual filter using intelligent estimation of noise pattern from a band degraded by additive noise. The proposed method doesn`t use the estimated noise which is obtained from silent range. Instead new estimated noise according to the power of signal and effect of noise variation is considered for each frame. So the noisy audio signal is enhanced by the method which controls a estimation of noise Pattern effectively in a noise corruption band. To show the performance of the proposed algorithm, various input signals which had a different signal-to-noise ratio(SNR) such as were used to test the proposed algorithm. we carry out SSNR and NMR of objective measurement and MOS test of subjective measurement. An approximate improvement of in SSNR and in NMR is achieved with the input signals, respectively. And we confirm the enhancement of tone quality in terms of mean opinion score(MOS) test which is result of subjective measurement.