Quality Of Service Metrics Research Articles

Performance Evaluation of Ethernet Network for Mobile Fronthual Networks

<p>Increasing mobile data traffic due to the rise of both smartphones and tablets has led to high-capacity demand of mobile data network. To meet the ever-growing capacity demand and reduce the cost of mobile network components, Cloud Radio Access Network (C-RAN) has emerged as a promising solution. In such network, the mobile operator’s Remote Radio Head (RRH) and Base Band Unit (BBU) are often separated and the connection between them has very tight timing and latency requirements imposed by Common Public Radio Interface (CPRI) and 3rd Generation Partnership Project (3GPP). This fronthaul connection is not yet provided by packet based network. To employ packet-based network for C-RAN fronthaul, the carried fronthaul traffic are needed to achieve the requirements of fronthaul streams. For this reason, the aim of this paper is focused on investigating and evaluating the feasibility of Ethernet networks for mobile fronthaul. The fronthaul requirements used to evaluate and investigate this network are maximum End to End (E2E) latency, Packet Loss Ratio (PLR) and Packet Delay Variation (PDV). The simulated results and numerical analysis confirm that the PDV and PLR of High Priority (HP) traffic in Ethernet network meet the requirements of mobile fronthaul using CPRI. However, the PDV of HP traffic meets the fronthaul network when the number of nodes in the Ethernet network is at most four. For Ethernet network, the number of nodes in the network limits the maximum separation distance between BBU and RRH (link length); for increasing the number of nodes, the link length decreases. Consequently, Radio over Ethernet (RoE) traffic should receive the priority and Quality of Service (QoS) HP can provide. On the other hand, Low Priority (LP) classes are not sensitive to QoS metrics and should be used for transporting time insensitive applications and services.</p>

QoS Performance of Integrated Hybrid Optical Network in Mobile Fronthual Networks

<p>Cloud Radio Access Network (C-RAN) has emerged as a promising solution to meet the ever-growing capacity demand and reduce the cost of mobile network components. In such network, the mobile operator’s Remote Radio Head (RRH) and Base Band Unit (BBU) are often separated and the connection between them has very tight timing and latency requirements. To employ packet-based network for C-RAN fronthaul, the carried fronthaul traffic are needed to achieve the requirements of fronthaul streams. For this reason, the aim of this paper is focused on investigating and evaluating the feasibility of Integrated Hybrid Optical Network (IHON) networks for mobile fronthaul. TransPacket AS (www.transpacket.com) develops a fusion switching that efficiently serves both Guaranteed Service Transport (GST) traffic with absolute priority and packet switched Statistical Multiplexing (SM) best effort traffic. We verified how the leftover capacity of fusion node can be used to carry the low priority packets and how the GST traffic can have deterministic characteristics on a single wavelength by delaying it with Fixed Delay Line (FDL). For example, for L<sub>1GE </sub><sup>SM</sup> =0.3 the added SM traffic increases the 10GE wavelength utilization up to 89% without any losses and with SM PLR=1E<sup>-03</sup> up to 92% utilization. The simulated results and numerical analysis confirm that the PDV and PLR of GST traffic in Ethernet network meet the requirements of mobile fronthaul using CPRI. For Ethernet network, the number of nodes in the network limits the maximum separation distance between BBU and RRH (link length); for increasing the number of nodes, the link length decreases. Consequently, Radio over Ethernet (RoE) traffic should receive the priority and Quality of Service (QoS) HP can provide. On the other hand, Low Priority (LP) classes are not sensitive to QoS metrics and should be used for transporting time insensitive applications and services.</p>

Energy consumption and quality of service in WBAN: A performance evaluation between cross-layer and IEEE802.15.4

Dentro de los esquemas de comunicación de redes inalámbricas de área corporal (WBAN), se encuentran los protocolos de capa cruzada, constituidos en una novedosa opción para alcanzar un balance efectivo entre consumo eficiente de energía y métricas de desempeño. En el presente trabajo, evaluamos el desempeño de una estrategia de capa cruzada al compararla contra los protocolos del estándar IEEE802.15.4 en una WBAN. Se evaluó el desempeño de ambas estrategias empleando una simulación de redes WBAN. Luego se ejecutó una comparación estadística y se encontró que la estrategia de capa cruzada ofrece un mejor desempeño con respecto a la compensación entre consumo eficiente de energía y algunas métricas de desempeño en nuestra WBAN. Observamos que en general, la estrategia de capa cruzada supera a ambos modos del estándar IEEE802.15.4 (ranurado y no-ranurado) con respecto a consumo eficiente de energía, retraso extremo a extremo, tasa de pérdida de paquetes y goodput.

Pseudo-Separation for Assessment of Structural Vulnerability of a Network

Based upon the idea that network functionality is impaired if two nodes in a network are sufficiently separated in terms of a given metric, we introduce two combinatorial pseudocut problems generalizing the classical min-cut and multi-cut problems. We expect the pseudocut problems will find broad relevance to the study of network reliability. We comprehensively analyze the computational complexity of the pseudocut problems and provide three approximation algorithms for these problems. Motivated by applications in communication networks with strict Quality-of-Service (QoS) requirements, we demonstrate the utility of the pseudocut problems by proposing a targeted vulnerability assessment for the structure of communication networks using QoS metrics; we perform experimental evaluations of our proposed approximation algorithms in this context.

QoS metrics modeling and analysis for neighborhood area network in smart grid applications

Recently, planning and designing of smart‐grid (SG) neighborhood area network (NAN) communication architecture has drawn wide attention of researchers. In order to establish an SG NAN scheme satisfying the requirement, a quality of service (QoS) metric is a critical demand. However, there are few studies on the implementation of an efficient QoS metric model. In this paper, we propose an innovative QoS metric model for SG NAN design. By exploring the natural characteristics of SG messages in many applications, we choose the reliability and latency of a message as the most important criteria and implement the QoS curve for evaluating the performance of any candidate communication scheme. In addition, we present the evaluation model for QoS metrics of multiple SG services in NAN. Compared to other existing QoS methods, our model is easy to use and helps to reduce the time and cost in the planning and designing of a NAN for SG. Simulation and analysis results indicate good agreement with our proposed QoS model. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

OpenIPTV: a comprehensive SDN-based IPTV service framework

IPTV is an emerging TV content delivery service that should guarantee Quality of Service (QoS) to deliver television contents over IP for their customers. However, providing such QoS regarding service level agreements (SLA) requires frequent service monitoring and adaptive configuration mechanisms. Nowadays, Software Defined Networks (SDNs) provide capabilities to deploy and manage networks dynamically and can maintain QoS. In this paper, a novel IPTV service framework (OpenIPTV) is proposed, which utilizes SDN as an underlying technology for providing QoS for IPTV customers in a shared backbone network. OpenIPTV is implemented in a well-known OpenDayLight controller and strictly followed a modular design for the sake of efficiency. OpenIPTV comprises all service requirements such as resource monitoring, channel changing, multicast group managing and dynamic QoS multicast traffic engineering. The performance of OpenIPTV is evaluated under different scenarios and experimental results confirmed the effectiveness of the proposed framework in terms of QoS metrics. Furthermore, experimental results show that OpenIPTV is a feasible and practical solution to deliver IPTV services with high level of QoS over SDN.

Physical layer security-aware routing and performance tradeoffs in ad hoc networks

The application of physical layer security in ad hoc networks has attracted considerable academic attention recently. However, the available studies mainly focus on the single-hop and two-hop network scenarios, and the price in terms of degradation of communication quality of service (QoS) caused by improving security is largely uninvestigated. As a step to address these issues, this paper explores the physical layer security-aware routing and performance tradeoffs in a multi-hop ad hoc network. Specifically, for any given end-to-end path we first derive its connection outage probability (COP) and secrecy outage probability (SOP) in closed-form, which serve as the performance metrics of communication QoS and transmission security, respectively. Based on the closed-form expressions, we then study the security-QoS tradeoffs to minimize COP (resp. SOP) conditioned on that SOP (resp. COP) is guaranteed. With the help of analysis of a given path, we further propose the routing algorithms which can achieve the optimal performance tradeoffs for any pair of source and destination nodes in a distributed manner. Finally, simulation and numerical results are presented to validate the efficiency of our theoretical analysis, as well as to illustrate the security-QoS tradeoffs and the routing performance.

The capacity of QoE for wireless networks with unreliable transmissions

Video streaming is anticipated to dominate wireless traffic in the near future. We study wireless systems where an access point delivers video streams to multiple clients over unreliable wireless channels. The performance of each client is measured by the amount of time that its video playback halts due to buffer underflow, which has been shown to have the most impact on clients’ perceived quality of experience (QoE). This performance measure is significantly different from traditional quality of service metrics. We develop an analytic framework that jointly captures the video playback process and the unreliable and heterogeneous wireless channels. We use a diffusion limit to approximate the short-term QoE performance. We derive the capacity region for QoE by establishing a lower bound of a weighted sum of video halt durations over all clients. We then propose a QoE-optimal policy that can achieve every point within the capacity region. Finally, we compare our policy against two commonly used policies. Both theoretical analysis and simulation results show that our policy greatly outperforms other policies.

Comparative Service Quality Metrics in Regular and Nonregular Undergraduate Marketing Programs: Implications for Marketing Education and Professionalism

Nonregular higher education in Nigeria became an integral part of the university manpower development since 1960, when the Ashby Commission recommended establishing evening degree programs. These ubiquitous programs have contributed to national capacity-building and remain relatively unmonitored by the National Universities Commission. This article examined the relative service quality levels among 368 undergraduate students from the regular and nonregular marketing programs at Abia State University. The regular program served as the control. The study found that besides long results’ turnaround time being the nonregular students’ dominant stressor (followed by the state of facilities), the nonregular program deviated from an ideal benchmark by 81% as opposed to the regular program’s 47%. The study recommended a paradigm shift in competitive university governance for nonregular marketing programs that prioritizes speedy results publication and facilities upgrade.

Algebra and algorithms for multipath QoS routing in link state networks

The diversity of quality-of-service (QoS) requirements of Internet applications motivates various QoS routing algorithms that take different QoSmetrics into consideration. Routing algebra has been proposed as a framework to study the fundamental properties of QoS routing algorithms, such as their optimality and loopfreeness. However, for multipath QoS routing, little has been done in these aspects. Existing multipath QoS routing algorithms often take a rather conservative approach to guarantee loop-freeness, at the cost of efficiency. On the other hand, simply adapting existing efficient multipath routing algorithms to support various QoS metrics cannot guarantee correctness. In face of that, we propose a routing metric algebra for multipath QoS routing in link state networks, where a key property of the routing metrics called isotonicity, which plays an important role. To let routers efficiently and correctly find multiple next-hops for each destination, we also develop two distributed multipath QoS routing algorithms. The algorithms are run locally and independently, without exchanging messages other than the basic link states. They are specifically tailored for algebras with strict or non-strict isotonicity, and their correctness is formally proved.

Service Mining for Trusted Service Composition in Cross-Cloud Environment

Nowadays, with the cloud's charismatic storage and computation power, more and more traditional services (social networking service, location-based services, etc.) are being migrated onto cloud platforms. These cloud services on different cloud platforms could be employed to form cross-cloud mobile applications of mobile cyber-physical systems (CPS). However, a cloud service may have various versions of quality of service (QoS) information revealed in different mobile CPS applications, which is often advertised as the elastic computation power. This characteristic makes it costly and time consuming to mine qualified ones from massive candidate cloud services for developing a mobile CPS application, as a service composition solution may have various evaluated values initiated by the various QoS properties. In view of this challenge, a cloud service selection method, named CSSM, is proposed in this paper. It takes the utility value as the evaluation index and aims at finding optimal or near-optimal trusted service composition solutions from a set of cloud services on users' demands. Technically, the user preference on each QoS metric is formalized as the preference interval for enhancing the fitness of a service composition solution. Furthermore, an extended top- $k$ iteration composition process is performed among cloud services to get an optimal or near-optimal trusted service composition solution. Both theoretical analysis and experimental evaluation are conducted to guarantee the feasibility and efficiency of the CSSM.

Enhance the Quality of Service in Mobile Ad Hoc Networks by Using Fuzzy Based NTT–DYMO

The dynamic nature of Mobile Ad hoc Networks (MANETs) demands a new-fangled set of communication strategies to enhance the performance of Quality of Service (QoS). It is very difficult to find viable QoS routes in MANETs due to its environment. AODV version 2 is called Dynamic MANET On-demand (DYMO) Routing protocol. Drawback of AODV is, it does not support larger networks. DYMO supports both medium and larger networks. To enhance the performance of DYMO, this paper proposes FBNTT DYMO by applying dynamic Node Traversal Time (NTT) in place of defacto NTT using fuzzy logic and Matlab. Fuzzy concept is used by taking network size and mobility is inputs and NTT as output. NTT plays a vital role in improving QoS in MANETs. For the Existing DYMO the default NTT value is 90 ms in QualNet simulator, however in a lively and dynamic environment we should not depend on the static values during protocol configuration. This paper implements FBNTT DYMO using QualNet simulator. The QoS metrics used are: throughput, delay, jitter and First packet received. The experimental result reveals that FBNTT DYMO radically improves the QoS as compared with defacto NTT–DYMO.

Performance analysis and power allocation for the unsaturated two‐user interference channel

The performance analysis is important for quality of service (QoS) guarantee, which has not been well studied in the interference-limited system. The authors study the QoS performance of each user in an interference-limited system when the power control policy is used to maximise the sum rate of users. Since service processes of users are correlated, the authors first propose a two-dimensional Markov chain to model the transition among queue states of users. Through solving the Markov chain, the authors derive the closed-form formulae of the stationary probability of the queue length and other QoS metrics of each user. The analysis results indicate that the power allocation problem should be reconsidered in unsaturated networks since the power allocation policy designed for saturated networks is no longer appropriate. The authors thus develop a new power allocation algorithm which considers queue length and channel quality jointly. Finally, the simulation results verify that the authors’ analytical method provides accurate estimations of QoS metrics and the proposed algorithm enhance the power efficiency and improve the queue performance of each user.

Multi-objective Optimization Model for Service Node Selection Based on Trade-off between Quality of Service and Resource Consumption in Mobile Crowd Sensing

As mobile crowd sensing (MCS) cannot provide reliable services, the quality of service (QoS) is a major research interest. Since the service node makes a decisive impact on two vital factors of QoS, service node selection is becoming a novel research direction in MCS. In this paper, we analyze the factors that need attention when selecting proper service nodes in MCS and define the service node selection problem (SNSP) as follows: finding the optimal set of service nodes, provided that optimizes multiple metrics of QoS simultaneously and satisfies the network resource constraint. Accordingly, we formulate a multiobjective optimization model (MOOM), which converts SNSP to a multiobjective optimization problem (MOOP). Since the MOOM considers the comprehensive effect of all service nodes on one metric as one objective of MOOP, it can handle the diversity of metrics and conflicts between them; in particular, it can flexibly change the metric system of QoS depending on different demands. To demonstrate the value and effectiveness of the proposed MOOM, we propose a paradigm of it and design a corresponding multiobjective optimization selection mechanism. This paradigm focuses on the influence of node spatiotemporal mobility on both data collection and data transmission. Extensive experiments and comparison on a real-world data show that MOOM is an effective model for selecting service nodes with both good coverage and transmission performances.

Transmission-Rate-Adaption Assisted Energy-efficient Resource Allocation with QoS Support in WBANs

With the advances in wearable sensors and wireless technologies, wireless body area network (WBAN) has become a promising network to provide health applications, such as ubiquitous e-Health services and real-time health monitoring. In these WBANs, quality of service (QoS) requirements, including packet loss rate, throughput, and delay, need to be guaranteed for providing reliable and real-time data transmission even under highly dynamic environment due to human mobility and postures. Meanwhile, energy efficiency is another key factor to consider for increasing the network lifetime in such a resource-constrained network. In this paper, a transmission-rate-adaption assisted and energy-efficient resource allocation scheme is proposed in which both constraints of QoS metrics and the characteristics of dynamic links are considered. Specifically, a QoS optimization problem is formulated to optimize the transmission power and time slots for each sensor, which minimizes energy consumption subjected to the QoS constraints. Due to the dynamic link characteristics, the link quality may become poor, and then the QoS requirements of normal packets and emergency packets cannot be satisfied. Besides, the emergency packets should receive more attentions with a high priority and high QoS requirements. To guarantee the QoS requirements when the link is very poor, a transmission rate adaption policy is proposed to carefully adjust the transmission rate at each sensor to assist the QoS optimization problem, and a priority-based retransmission strategy is designed to apply the retransmission strategy to further improve the performances of the emergency packets with a high priority. Numerical results demonstrate the effectiveness of the QoS optimization problem, the proposed transmission rate adaption policy, and the priority-based retransmission strategy.

Optimization Based Hybrid Congestion Alleviation for 6LoWPAN Networks

The IPv6 over low-power wireless personal area network (6LoWPAN) protocol stack is a key part of the Internet of Things (IoT) where the 6LoWPAN motes will account for the majority of the IoT “things.” In 6LoWPAN networks, heavy network traffic causes congestion which significantly effects the network performance and the quality of service metrics. Generally, two main strategies are used to control and alleviate congestion in 6LoWPAN networks: 1) resource control and 2) traffic control. All the existing work of congestion control in 6LoWPAN networks use one of these. In this paper, we propose a novel congestion control algorithm called optimization-based hybrid congestion alleviation (OHCA) which combines both strategies into a hybrid solution. OHCA utilizes the positive aspects of each strategy and efficiently uses the network resources. The proposed algorithm uses a multiattribute optimization methodology called gray relational analysis for resource control by combining three routing metrics (buffer occupancy, expected transmission count, and queuing delay) and forwarding packets through noncongested parents. Also, OHCA uses optimization theory and network utility maximization framework to achieve traffic control when the noncongested parent is not available where the optimal nodes’ sending rate are computed by using Lagrange multipliers and Karush–Kuhn–Tucker conditions. The proposed algorithm is aware of node priorities and application priorities to support the IoT application requirements where the applications’ sending rate allocation is modeled as a constrained optimization problem. OHCA has been tested and evaluated through simulation by using Contiki OS and compared with comparative algorithms. Simulation results show that OHCA improves performance in the presence of congestion by an overall average of 28.36%, 28.02%, 48.07%, 31.97%, and 90.35% in terms of throughput, weighted fairness index, end-to-end delay, energy consumption, and buffer dropped packets as compared to duty cycle-aware congestion control for 6LoWPAN networks and queue utilization-based-IPv6 routing protocol for low-power and lossy network.

WebRTC Testing: Challenges and Practical Solutions

WebRTC comprises a set of novel technologies and standards that provide Real-Time Communication on Web browsers. WebRTC makes simple the embedding of voice and video communications in all types of applications. However, releasing those applications to production is still very challenging due to the complexity of their testing. Validating a WebRTC service requires assessing many functional (e.g. signaling logic, media connectivity, etc.) and non-functional (e.g. quality of experience, interoperability, scalability, etc.) properties on large, complex, distributed and heterogeneous systems that spawn across client devices, networks and cloud infrastructures. In this article, we present a novel methodology and an associated tool for doing it at scale and in an automated way. Our strategy is based on a blackbox end-to-end approach through which we use an automated containerized cloud environment for instrumenting Web browser clients, which benchmark the SUT (system under test), and fake clients, that load it. Through these benchmarks, we obtain, in a reliable and statistically significant way, both network-dependent QoS (Quality of Service) metrics and media-dependent QoE (Quality of Experience) indicators. These are fed, at a second stage, to a number of testing assertions that validate the appropriateness of the functional and non-functional properties of the SUT under controlled and configurable load and fail conditions. To finish, we illustrate our experiences using such tool and methodology in the context of the Kurento open source software project and conclude that they are suitable for validating large and complex WebRTC systems at scale.

QMCP: QoS Aware Multi-Channel Path Discovery for End to End Data Transmission Over Cognitive Radio Ad Hoc Networks

ICT (Information and Communication Technology) trends are fast emerging and globally leading to the substantial demand of spectrum channels used for wireless networks. Cognitive Radio (CR) is an emerging technology solution that shall work on dynamic spectrum channel allocation. In cognitive radio ad hoc networks (CRAN), it is often difficult to establish the path among nodes with direct channel. Hence it is obvious to establish the path through the set of channels in sequence. The constraint is quality of service (QoS). Path establishment by the multiple channels in sequence needs a dynamic channel assignment for ensuring an optimum utilization of the available resources, whilst minimizing the interference in a network. In this paper, the emphasis is on Multichannel transmission Path with optimal QoS fitness for Cognitive Radio Networks. The proposed model is called QoS aware Multi-Channel Path (QMCP) discovery for end-to-end data transmission over CRAN. The QMCP performs the evolutions using adaptive genetic algorithm on the initial multichannel paths discovered in order to obtain the best fit path. The QoS metrics defined in our earlier contribution are used in fitness function. Results from the study reflect the robustness of the proposed model which could certainly impact the quality of channel assignment in CRNs. Since the adaptive genetic algorithm is used, the process complexity and completion time of the QMCP are also assessed.

Context-aware, user-driven, network-controlled RAT selection for 5G networks

It is expected that in the very near future, cellular networks will have to deal with a massive data traffic increase, as well as a vast number of devices. Optimal placement of the end devices to the most suitable access network is expected to provide the best Quality of Service (QoS) experience to the users but also the maximum utilization of the scarce wireless resources by the operators. Several on-going proposals attempt to overcome the existing barriers by enabling the use of Wi-Fis and femto-cells to cater for part of the load generated by the end devices. The evolution of the Access Network Discovery and Selection Function (ANDSF) for the core part of the cellular network, as well as the Hotspot 2.0 approach, are currently being subject to thorough discussions and studies and are expected to facilitate a seamless 3GPP-WiFi interworking. During the past years, several Radio Access Technology (RAT) selection schemes have been proposed. However, these schemes do not take into consideration the opportunities offered by these new standardized approaches. Our paper acts in a manifold way: Firstly, it proposes COmpAsS, a Context-Aware RAT Selection mechanism, the main part of which operates on the User Equipment (UE)-side, minimizing signaling overhead over the air interface and computation load on the base stations. Secondly, we discuss in detail the architectural perspective; i.e., the extensions needed in the network interfaces that enable the exchange of the required context information among the respective network entities and in accordance with the 3GPP trends in relation to the context-aggregating entities. Furthermore, we quantify the signaling overhead of the proposed mechanism by linking it to the current 3GPP specifications and performing a comprehensive per-parameter analysis. Finally, we evaluate the novel scheme via extensive simulations in a complex and realistic 5G use case, illustrating the clear advantages of our approach in terms of key QoS metrics, i.e. the user-experienced throughput and delay, both in the uplink and the downlink.

A Constellation Design Methodology Based on QoS and User Demand in High-Altitude Platform Broadband Networks

An investigation into the constellation design methodology of high-altitude platform (HAP) broadband networks is presented. The quality of service (QoS) metrics and user demand model are established in the HAP broadband networks. Each HAP is seen as a mobile base station, and a methodology of mobile base station placement is proposed with QoS and user demand guarantee for the first time. The multiple HAP coverage is analyzed with link geometry based on the single HAP coverage model. Besides, a cost-efficient optimization design framework for the HAP constellation is established by optimizing the design vector to maximize the network capacity per cost under the constraints of QoS metrics. In addition, the optimization model and improved artificial immune algorithm based on immune review are designed, and performance of the proposed method is demonstrated through in-depth numerical simulations. Simulation results show that the proposed constellation design method can effectively solve the problem of the mobile base station layout in the HAP broadband networks.