No. 1 (2015)
Published:
2015-03-30
ARTICLES FROM THIS ISSUE
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New Tool for Investigating QoS in the WWW Service
Abstract
The subject of this paper is the QoS measurement in the World Wide Web (WWW) service. It will begin with a brief presentation of methods currently used to measure QoS in the WWW service before going on to describe in detail the new tool QoSCalc(WWW). Following that, the potential of the new tool will be put to the test in a series of analysis scenarios. The results and insights obtained will then be presented in several diagrams, and interpreted.
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Revising and Improving the ITU-T Recommendation P.912
Abstract
It was once thought that high Quality of Service (QoS) performance solves recurrent problems of lowquality multimedia services. Since then, solutions have been proposed to ensure a high level of Quality of Experience (QoE). In this paper, the author attempts to outline an understanding of an accurate meaning of multimedia services quality. Starting from QoS and passing through generalized QoE, the author focuses on subjective aspects and objective quality modeling and optimization of visual performance for Target Recognition Video (TRV) applications (such as video surveillance), to outline the ITU-T standardization path in this area. The revising the ITU-T Recommendation P.912 is proposed to reflect improved subjective test techniques developed since this Recommendation was approved. Also at least some existing errors of reasoning are predicted, which are likely to become evident for the industry in the next decade. Finally, the author invites all researchers working on topics related to TRV to join him in the process of improving P.912.
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Quality Expectations of Mobile Subscribers
Abstract
Mobile systems, by nature, have finite resources. Radio spectrum is limited, expensive and shared between many users and services. Mobile broadband networks must support multiple applications of voice, video and data on a single IP-based infrastructure. These converged services each have unique traffic holding and quality requirements. A positive user experience must be obtained through efficient partitioning of the available wireless network resources. The 3 rd Generation Partnership Project (3GPP) has developed a comprehensive Quality of Service (QoS) parameter to address this problem. The regular control of service quality is critical for operators to ensure user Quality of Experience (QoE), establish new business models and monetize services. It enables operators to employ fair-use resource policies and maintain network performance during peak traffic times. Wireless mobile communication is tending towards an integrated system of Internet and telecommunication technologies, where mobile users move freely anytime and everywhere. They desire to communicate with any device using the best service available. In this paper QoS management issues in mobile communication are described. The authors present an insight into subscriber behavior and related factors that affect the QoE of mobile data services.
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Silent Calls – Causes and Measurements
Abstract
The quality of telephone services is very important from either operator or subscriber point of view. One of the negative phenomenon which affects quality of telephone services is lack of speech signal during a call. This situation occurs relatively frequently in mobile telephony, and is called silent call (SC). Lack of speech signal can occur only once or many times during the call, and degrade connection quality. In this paper, an analysis of this phenomenon is presented. The research base are the results of measurements mobile network one of operators in Trójmiasto a large urban area consisting of three cities: Gdańsk, Gdynia, and Sopot. To estimate impact of silent calls on speech quality, mean opinion score index was calculated using POLQA algorithm.
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Prospects and QoS Requirements in 5G Networks
Abstract
In this article the requirements to some number of KPI that determine the quality of service (QoS) in 5G networks are formulated. The proposed QoS requirements are based on the analysis of functional requirements to 5G networks and traffic parameters for HD video and massive M2M services, which will be highly demanded in 2020. One of the 5G development paradigms is the network function virtualization (NFV) including cloud radio access and cloud core networks. The authors have proposed the concept of function blocks CQMF and CQCF to control and monitor QoS, which are implemented as part of the 5G network cloud infrastructure.
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Possibilities to Optimize QoS with Next SON Versions
Abstract
The paper discusses quality of service in LTE and LTE-A networks seen as a challenge that can be met with SelfOrganizing Networks (SON) functionalities. The SON concepts have been included in the LTE (E-UTRAN) standards since the first release of the LTE technology. Self-optimization functionalities will monitor and analyze performance measurements, notifications, and self-test results and will automatically trigger re-configuration actions on the affected network nodes when necessary. The SON specifications have been built over the existing 3GPP network management architecture, the ultimate implementation of SON in 4G networks will bring many advantages. Successive SON procedures are waiting for their time and money to be implemented in 4G, though some essential issues for example of inter Radio Access Technology (RAT) interfaces must be overworked.
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Utilization of the Software-Defined Networking Approach in a Model of a 3DTV Service
Abstract
In article a new concept concerning multimedia service modeling of stereoscopic motion pictures distribution is depicted. Presented conceptual model utilizes functionality approach supported by a Software-defined Networking (SDN) architecture. The core elements composing the proposed 3D television service are stated, depicting internal arrangement of a modern 3DTV service. Moreover, investigated examples of a functional utilization of the SDN approach in a 3DTV service model realization reveal key improvements towards greater flexibility and efficiency in heterogeneous users environment.
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Subjective Assessment for Standard Television Sequences and Videotoms - H.264/AVC Video Coding Standard
Abstract
This paper presents comparison of videotoms and standard television sequences in terms of image distortions and perceived subjective quality affected by H.264/AVC compression with changed bit rate. Results from initial tests, performed as laboratory exercise can be a reference to show scale of diversity in both level of degradation and Mean Opinion Score (MOS) evaluation. Results and comments included in this paper give overview on the codec influence on videotoms and can suggest approach for further tests and experiments.
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A New Implementation of UWB CRLH Based Antennas for Wireless Communications
Abstract
In this article, a novel ultra wideband (UWB) small antennas based on the composite right/left-handed transmission lines structures are proposed. The antennas are presented with best in size, bandwidth and radiation patterns. Their physical size and the operational frequency depend on the unit cell size and the equivalent transmission line model parameters of the CRLH-TL. To realize characteristics of first proposed model, Q-shaped gaps printed into rectangular radiation patches are used. The antenna based on composite right/left-handed transmission lines is composed of two unit cells, each of which occupies only 10.8 × 8.6 mm and covers the 2.7–9.3 GHz bandwidth for VSWR < 2. The peak gain and radiation efficiency, are 5.78 dBi and 42.1% 9.3 GHz, respectively. Moreover, the second designed antenna has the same size and enhancement bandwidth, gain and radiation efficiency than the first proposed antenna with similar design procedure. It is constructed of the printed Q-shaped four unit cells. The length, width and height are 21.6, 8.6 and 1.6 mm, respectively, and it covers 4.1–11.7 GHz bandwidth for VSWR < 2 having highest gain (7.18 dBi) and radiation efficiency (92.69%) at 4.1 GHz.
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Availability of WDM Multi Ring Networks
Abstract
This paper presents a new approach to modeling the availability of the networks composed of multiple interconnected rings in two nodes. For availability modeling method algebraic formulation is used. Using this method, through the availability of multiple ring networks consisting of two and three-rings connected to two nodes, a general expression for the availability between two terminals of multiple ring networks is derived. To perform the expression some real assumptions were taken and the analytical calculation showed that the use of these expressions under these assumptions provides real values for availability between the two terminals of multiple ring networks. Information on the availability of links and nodes is taken from previously published works.
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Assessment of Area Energy Efficiency of LTE Macro Base Stations in Different Environments
Abstract
Energy efficiency (EE) of wireless telecommunications has become a new challenge for the research community, governments and industries in order to reduce CO2 emission and operational costs. EE of base stations (BSs) in cellular networks is a growing concern for cellular operators to not only maintain profitability, but also to reduce the overall negative impact to the environment and economic issues for wireless network operators. In this paper, a framework focuses on the Area Energy Efficiency (AEE) evaluation of LTE BSs is presented. The parameters affect on the AEE and the coverage area of LTE BS in different scenarios are investigated. AEE analysis has been done using a few key performance indicators including transmit power, bandwidth, load factor with the assumption of different scenarios (urban, suburban and rural). The simulation results show that the LTE BSs have better AEE in an urban environment for cell radius less than 750 m compare with the suburban and rural environments. Furthermore, it is obvious that there is a strong influence of traffic load, BW and transmission power on AEE of LTE network. On the other hand, AEE increases significantly as the BW size increases. Finally, it has been shown that the AEE of LTE macro BS decreases with increasing the percentage of traffic load for all scenarios.
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Performance Comparison of Four New ARIMA-ANN Prediction Models on Internet Traffic Data
Abstract
Prediction of Internet traffic time series data (TSD) is a challenging research problem, owing to the complicated nature of TSD. In literature, many hybrids of auto-regressive integrated moving average (ARIMA) and artificial neural networks (ANN) models are devised for the TSD prediction. These hybrid models consider such TSD as a combination of linear and non-linear components, apply combination of ARIMA and ANN in some manner, to obtain the predictions. Out of the many available hybrid ARIMA-ANN models, this paper investigates as to which of them suits better for Internet traffic data. This suitability of hybrid ARIMAANN models is studied for both one-step ahead and multistep ahead prediction cases. For the purpose of the study, Internet traffic data is sampled at every 30 and 60 minutes. Model performances are evaluated using the mean absolute error and mean square error measurement. For one-step ahead prediction, with a forecast horizon of 10 points and for three-step prediction, with a forecast horizon of 12 points, the moving average filter based hybrid ARIMA-ANN model gave better forecast accuracy than the other compared models.
