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While comparing with the existing networks, Wireless Mesh Network has the advantages of fast implementation, low direct investment and easy maintenance. During their existence time Wireless Mesh Networks (WMNs) experience frequent link failures caused by channel interference, dynamic obstacles, and/or applications bandwidth demands. Wireless mesh networks should be recovered from these link and node failures. These failures cause severe performance degradation in WMNs. In WMNs, the quality of the link can rapidly change because of varying environment condition. The routing algorithm must be able to cope with such changes in link quality and provide alternate route in case the link becomes unusable. This paper proposes a Cost efficient fast autonomous reconfiguration system (C-FARS) which provides the multiradio Wireless Mesh Networks to recover from link failure automatically to maintain the network performance. C-FARS generates necessary changes in local radio and channel allocations in order to recover from failures. C-FARS recovers from link failures by making cost effective local configuration changes with minimum delay that satisfies the applications QoS demands instead of making global network changes. Our Implementation results shows that C-FARS outperforms existing failure-recover schemes in improving channel-efficiency by more than 95%, also reduces the cost and delay. [ABSTRACT FROM AUTHOR]

In this paper was considered mechanism separation network traffic into a small number of classes with the purpose of each class of a numeric attribute - priority and also was analyzed the structure of the queue for the five traffic classes, which are served consistently and cyclically and each cycle of each line is drawn is the number of bytes, which corresponds to the weight of queuing. [ABSTRACT FROM AUTHOR]

As broadband access is evolving from digital subscriber lines to optical access networks, the Gigabit Passive Optical Network (GPON), can provide huge bandwidth capacity, low cost, simple architecture and easy maintenance, have emerged as one of the most promising access network technologies for future last-mile solutions. To prevent data collision and ensure efficient transmission, the point-to-multipoint topology of GPONs requires a time-division media access control (MAC) protocol to allocate the shared resource of a common upstream transmission medium. Therefore, Dynamic Bandwidth Allocation (DBA) is an open and hot topic in the GPON. However, most proposed DBA plans to ignore the impact of the maximum cycle time for Quality of Service (QoS) ensures maximum delay and jitter of real-time traffic, uplink bandwidth utilization, drop probability and fairness in GPON upstream transmission. In this paper, we propose a Waited-based Dynamic Bandwidth Allocation called WDBA which is predict the arriving real time packet based on the proportion of waiting time for multiple services over GPONs. In addition to ensuring the quality of QoS, our work focus on the fundamental problem of trading-off between upstream channel utilization and maximum polling cycle time with different proportion of Traffic Containers (T-CONTs) traffic in a GPON with multiple ONUs and verify the accuracy of the analysis with simulations. Overall, our numerical results indicate that the packet delay, throughput and drop probability performance is better when the polling cycle time is longer; the fairness is better when the polling cycle time is shorter. [ABSTRACT FROM AUTHOR]

Many network services which process a large quantity of data and knowledge are available in the distributed network environment, and provide applications to users based on Service-Oriented Architecture (SOA) and Web services technology. Therefore, a useful web service discovery approach for data and knowledge discovery process in the complex network e nvironment i s a v ery s ignificant i ssue. U sing the traditional keyword-based search method, users find it difficult to choose the best web services from those with similar functionalities. In addition, in an untrustworthy real world environment, the QoS-based service discovery approach cannot verify the correctness of the web services' Quality of Service (QoS) values, since such values guaranteed by a service provider are different from the real ones. This work proposes a trustworthy two-phase web service discovery mechanism based on QoS and collaborative filtering, which discovers and recommends the needed web services effectively for users in the distributed environment, and also solves the problem of services with incorrect QoS information. In the experiment, the theoretical analysis and simulation experiment results show that the proposed method can accurately recommend the needed services to users, and improve the recommendation quality. [ABSTRACT FROM PUBLISHER]

Long Term Evolution (LTE) is the most promising technology for 4G mobile communication networks. The goal of LTE is to provide high data transmission rate, scalable bandwidth, low latency, and high-mobility. LTE employs Orthogonal Frequency Division Multiplexing (OFDM) and Single Carrier - Frequency Division Multiple Access (SC-FDMA) for downlink and uplink data transmission, respectively. As to SC-FDMA, there are two constraints in resource allocation. First, the allocated resource blocks (RB) should be contiguous. Second, these allocated resource blocks are forced to use the same modulation technique. This paper focuses on the resource allocation problem of LTE SC-FDMA system. The aim of this paper is to propose a QoS-constraint resource allocation scheduling to enhance data transmission on uplink SC-FDMA. The proposed scheduling is a three-stage approach. In the first stage, it uses a time domain scheduler to differentiate UE services according to different QoS service requirements. In the second stage, it uses a frequency domain scheduler to prioritize UE services based on channel quality. In the third stage, it limits the times of modulation downgrade in RBs allocation to enhance system throughput. In the simulations, the proposed method is compared to fixed sub-carrier dynamic resource allocation algorithm and adaptive dynamic sub-carrier resource allocation algorithm. Simulation results show that our method outperforms the other two methods in terms of throughput, transmission delay, packet loss ratio, and RB utilization. [ABSTRACT FROM PUBLISHER]

A Mobile Ad hoc Network (MANET) is an autonomous collection of mobile nodes forming a dynamic network and communicating over wireless links. Owing to its uniqueness such as easy deployment and self-organizing ability, it has shown great potential in many civil and military applications. As MANETs are gaining popularity, their need to support real time and multimedia applications is rising as well. Such applications have Quality of Service (QoS) requirements like bandwidth, end-to-end delay, jitter and energy. Consequently, it becomes very necessary for MANETs to have an efficient routing and QoS mechanism to support these applications. A number of QoS routing protocols with distinguishing features have been proposed recently. This paper presents a thorough overview of some of the QoS routing protocols along with their strengths and weaknesses. A comparative study of the QoS routing protocols is done and in addition, the current issues and future challenges that are involved in this exciting area of research are also included. [ABSTRACT FROM PUBLISHER]

Mission-critical surveillance applications such as intrusion detection or disaster response have vital requirement in QoS. We consider a Wireless Image Sensor Network (WISN) with a scheduling of image sensor node's activity based on the application criticality level. Sentry nodes capable of detecting intrusions with a higher probability than others will alert neighbor nodes as well as activating cover sets member for image disambiguation or situation-awareness purposes. In order to optimize the performance of image transfer from multiple sensor nodes to the Sink we propose a 2-hop neighborhood information- based cover set selection to determine the most relevant cover sets. Then, in order to be consistent with our proposed approach, a multi-path extension of Greedy Perimeter Stateless Routing (called T-GPSR) wherein routing decisions are also based on 2-hop neighborhood information is proposed. Simulation results show that our proposal reduces packet losses, enabling fast packet delivery and higher visual quality of received images at the Sink. [ABSTRACT FROM PUBLISHER]

Tactical Data Link System always uses Time Division Multiple Access (TDMA) in Mac Layer. In TDMA, the channel is divided into time slots, and nodes are allocated slots to transmit data through the same time slot assignment algorithm. The tactical scenario is complicate and unpredictable, and some important messages need high Qos guarantee. It is hard to guarantee the Qos by the pre-allocated slot assignment protocol when the network is flooded, so Qos-based dynamic slot assignment protocol flourishes. But there is still a problem that low-priority message always suffers from starvation in these traditional Qos-based protocols. Thus, we propose a new Qos-based slot assignment protocol, which the frame length is changed dynamically according to the number of the requests in the network, to improve Qos performance of all kinds of messages. Through the simulation, we find that this protocol decreases the delay of messages of higher priority to some extent and obviously achieves desirable delay of the low priority message. Meanwhile, this protocol also improves the channel utilization. [ABSTRACT FROM PUBLISHER]

An important field of application of wireless ad-hoc networks are disaster scenarios. In fact, the self-organizing and infrastructure-less nature of wireless ad-hoc networks enables easy and quick deployment suitable for emergency situations and rescue operations. However, ensuring reliable communications over such networks might become challenging if quality of service (QoS) is not provided. Moreover, efficient use of available bandwidth is desirable. Medium access control (MAC) protocols play a major role in the reliability of wireless ad-hoc networks and contribute to their performance. The shared radio channel forms a broadcast domain and is prone to collisions that could hinder, e.g., efficient carry out of rescue calls. The objective of this paper is to introduce a simple MAC protocol with QoS support for real-time voice communications over wireless ad-hoc networks. We propose a modified medium access mechanism based on the widespread IEEE 802.11 standard. The proposed protocol guarantees bounded delays for voice traffic. It makes efficient use of bandwidth by handling both hidden and exposed node problems. [ABSTRACT FROM PUBLISHER]

The Next generation mobile communication system called as 4G is expected to include heterogeneous wireless networks that will offer high data rate multimedia services to end users. In present wireless systems the capability of broader coverage is available but has the limitation of bandwidth and network cost. The proposed Seamless Media Independent Resilience Triggering (SMIRT) framework will provide decision based on soft-handover for Heterogeneous Networks like Wi-Fi, WiMAX and LTE. It will provide seamless roaming across the heterogeneous networks through the media independent handover framework without user intervention. This framework will be simulated by using NS3 and evaluate the increased performances like throughput, QoS, coverage and decreased performances like packet loss and delay. [ABSTRACT FROM AUTHOR]

Cognitive radio makes it possible for an unlicensed user to access a spectrum opportunistically on the basis of non-interfering with licensed users. In this paper, we investigate the performance of opportunistic scheduling in an OFDMA-based cognitive radio (CR) systems by taking into the CR user's raw sensing information (RSI). We shall rely on the joint design framework to optimize a system utility, which adapts the packet delay and the throughput across the secondary users (under an average interference and total available power constraint) to guarantee Quality of Service (QoS) of the whole system. By maximizing the delay and throughput-based utility function, we can get the optimal subcarrier selection policy, power and modulation allocation for each SU's packet. Simulation results are presented to demonstrate the effectiveness of the proposed scheme. [ABSTRACT FROM PUBLISHER]

Predicting future values of Quality of Service (QoS) attributes can assist in the control of software intensive systems by preventing QoS violations before they happen. Currently, many approaches prefer Autoregressive Integrated Moving Average (ARIMA) models for this task, and assume the QoS attributes' behavior can be linearly modeled. However, the analysis of real QoS datasets shows that they are characterized by a highly dynamic and mostly nonlinear behavior to the extent that existing ARIMA models cannot guarantee accurate QoS forecasting, which can introduce crucial problems such as proactively triggering unrequired adaptations and thus leading to follow-up failures and increased costs. To address this limitation, we propose an automated forecasting approach that integrates linear and nonlinear time series models and automatically, without human intervention, selects and constructs the best suitable forecasting model to fit the QoS attributes' dynamic behavior. Using real-world QoS datasets of 800 web services we evaluate the applicability, accuracy, and performance aspects of the proposed approach, and results show that the approach outperforms the popular existing ARIMA models and improves the forecasting accuracy by on average 35.4%. [ABSTRACT FROM PUBLISHER]

Cloud computing is the computing paradigm which delivers IT resources as a service, hence user are free from setting up the infrastructure and managing hardware etc. Cloud Computing provides dynamic provisioned resources and presented as one or more integrated computing resources based on constraints. The process of provisioning in Clouds requires the application provisioner to compute the best software and hardware configuration so as to ensure that Quality of Services (QoS) target of application services are achieved, without compromising efficiency and utilization of whole system. This paper presents a dynamic provisioning technique, adapting to peak-to-peak workload changes related to applications to offer end-users guaranteed Quality of Services (QoS) in highly dynamic environments. Behavior and performance of applications and Cloud-based IT resources are modeled to adaptively serve end-user requests. Analytical performance (queuing network system model) and workload information are used to supply intelligent input about the physical infrastructure which causes improvement in efficiency. VM provisioning technique detects changes in workload intensity that occurs over time and makes appropriate changes in allocations of multiple virtualized IT resources to achieve application QoS targets. [ABSTRACT FROM PUBLISHER]

The number of wireless applications, services and devices such as mobile telephone handsets, laptops and personal digital assistant (PDAs) are growing rapidly. The next generation wireless technology systems are being devised with the vision of heterogeneity where a mobile user will be connected with multiple wireless networks like GPRS/UMTS, IEEE 802.1x, WiMAX and satellite etc. To connect the above devices, a primary interface can be assigned to a mobile node (MN). Mobile users should be connected with appropriate interfaces based on the application types and its requirements. Different types of services are provided by the Internet like file transfer, telephony, audio and video conferencing etc. Among these applications some are sensitive to delay, for example, audio and video conferencing and some are sensitive to quality like file sharing and remote login. This paper proposes a policy that determines different applications' requirements and chooses an appropriate interface as a primary interface for respective application based on the networks condition to improve Quality-of-Service (QoS). Prior to forward a packet to the destination, the routers decide the routes for that data packet to an appropriate interface that have been selected by the routers. It also helps to select the primary address among all available addresses based on an algorithm and reduces network overloads. [ABSTRACT FROM PUBLISHER]

Wireless Mesh Networks (WMNs) are now of the emerging networks in IP world, because of their robustness, simplicity, fault tolerant ability and fast deployment. Realizing the fact that there is adequate need of improvement in QoS researchers have been proposing various techniques to address the issue. We propose a scheme that is based on modification of Dynamic Reallocation of the Mesh Deterministic Access and MAC layer's contention-based distributed coordinated function (DCF) or contention window (CW) that is responsible for sharing the wireless medium. We study the influence of Mesh Coordination Function (MCF) and Hybrid Coordination Function (HCF) by modifying the normal MAC layer to improve and ensure Quality of Service by various parameters. The results obtained after simulations are quite promising and show that our proposed modification significantly improves QoS for WMNs to model presented in IEEE 802.11s/D4.0 [1]. [ABSTRACT FROM PUBLISHER]

The IEEE 802.11e standard is mostly concerned with traffic differentiation in single-hop infrastructured wireless networks. Wireless mesh networks use several wireless hops in order to forward packets to their destination. A significant issue is that the standard does not map network characteristics into the access protocol parameters it provides. This article investigates different configurations of the IEEE 802.11e access parameters in wireless mesh networks and proposes two configuration settings. Both proposals provide voice traffic service guarantee without significantly degrading the performance of other multimedia traffic classes, as demonstrated by simulation experiment results. [ABSTRACT FROM PUBLISHER]

For the issues of the existing method in the selection of web service blindness and customer service evaluation incredible, this paper presents a web service selection method based on credible user recommended and QoS. Firstly, searching for recommended user from the credible user group, distinguish the current user into the new user or old user, then adopt different recommended algorithm to form a list of web services' recommended degree, Secondly, introducing the QoS model, to provide more objective service selection and satisfy the users' preferences on QoS technical support, Finally, considering the accuracy of service feedback, the loop should be discovered and eliminated from the selected web service composition, which is in order to improve the service executive efficiency, and make the users' web service feedback more objective and accurate. The combination of these three processes, solved the service choice blindness and trust shortage, and effectively improved the reliability and accuracy of the service selection. The experimental results verified the validity of this method. [ABSTRACT FROM PUBLISHER]

The traffic demand in future mobile cellular networks is expected to increase exponentially which would lead to dense base station deployment and eventually higher energy consumption. The current dominant mobile systems including GSM and UMTS were not designed with focus on energy efficiency. This paper investigates the energy saving potential of pico nodes in a heterogeneous network from an incumbent operator consideration. The results show that the number of hotspots and the user distribution in the hotspots strongly effects the power saving. Also, sleep modes in pico base stations have shown to reduce the energy loss to almost half. On a day average with limited utilization of pico base station, the heterogeneous network scenario provides marginal saving. The results also show that if the pico base station resources are fully utilized, premium user case, the heterogeneous network scenario can provide substantial reduction in energy per bit. [ABSTRACT FROM PUBLISHER]

Mobile telecommunication operators are now focussing on emerging markets due to the current highly competitive mobile telecommunication sector in established markets. The deployment of wireless mobile infrastructure in these emerging markets or a green field scenario requires an innovative energy efficient approach, which is not feasible in an incumbent operator scenario. This paper describes a combined macro and pico cellular heterogeneous wireless network architecture, and analyses its energy efficiency with respect to variation in inter site distance. The increase in capacity and power saving through sparse network deployment is investigated in terms of area spectral efficiency and area power consumption respectively. The results suggest that the deployment of pico cells along with a traditional cellular network can improve the energy efficiency of the network, as well as provide gains in terms of increased inter site distance. Finally. the indifference curves of Energy Efficiency and number of pico nodes indicate the optimum deployment scheme for multiple area spectral efficiency targets. [ABSTRACT FROM PUBLISHER]

In this paper, we investigate spectrum sharing and multiple access problems for the high-rate ultra-wideband (UWB) systems. Based on the use of the linear precoded orthogonal frequency division multiplexing (LP-OFDM) proposed as an evolution of the well known multi-band OFDM (MB-OFDM) solution supported by the WiMedia Alliance for future high-rate UWB systems, the objective of this paper is to study a multiuser optimization spectrum sharing scheme for LP-OFDM UWB systems. This optimization study leads to a novel multiple access solution for the high-rate UWB systems. Simulation results demonstrate the efficiency of the use of the LP-OFDM transmission technique in the multiuser spectrum sharing scheme. Besides, the novel LP-OFDM multiuser spectrum sharing solution shows its capacity to provide a good tradeoff between the QoS support of the high-priority users and the fairness between the competing users. [ABSTRACT FROM PUBLISHER]

This paper presents the implementation of Quality of Service (QoS) based on the Class Based QoS IP Precedence in MPLS network. Most of the Internet Service Providers (ISP) need to use QoS since customers nowadays requires more bandwidth to support their network applications. ISP test lab has been used to implement QoS in MPLS network. Results obtained can be used by ISPs and Network Administrators in implementing the QoS and can be enhanced further with other type of queuing mechanism. [ABSTRACT FROM PUBLISHER]

The issue on how to guarantee the quality of service (QoS) is one of the hot topics for Test-Bed in cloud computing environment. In this paper, a new QoS evaluation model is proposed based on the evaluation index system. Firstly, the key parameters of QoS are determined as subjective index, objective index and the third-party index based on the evaluation index system. Then, a reasonable method is introduced to quantify the related indexes. Furthermore, the utility function is applied to evaluate the service from different providers. Finally, an experimental case is analyzed to illustrate the efficiency of the proposed method and the empirical results show that the method can effectively help the client to find the optimal services. [ABSTRACT FROM PUBLISHER]

Broadband services are changing our life. The applications of a variety of new services are also a profit growth point for operators. The evolution of the transmission quality for service has gradually attracted the operator's attention. In this paper, we classify the services of application from user's perspective, then describe and analyze service broadband in communication system in detail. Secondly, we research the Quality of Service (QoS) assessment and the evaluation of Quality of Experience (QoE) from the beginning of standards and technology, and then we analyze the relational model of QoS and QoE. Finally, the application prospects of broadband services are described in the future. [ABSTRACT FROM PUBLISHER]

Optical-wireless convergence is becoming one of the evolutionary technologies to provide quality-of-service (QoS) guaranteed ubiquitous access to end users. In this paper, we analyze the effect of GEPON cycle-length on the QoS performance of the GEPON-LTE converged network, when different resource handling mechanisms are used. The simulation results indicate that the influence of different cycle-lengths on the QoS performance varies depending on different traffic types and the resource handling mechanism used. We show that, this dependency can be reduced by introducing a unified resource handling mechanism which also improves the overall QoS performance of the converged network. [ABSTRACT FROM PUBLISHER]

Voice over IP (VoIP) service is emerging as a popular application in wireless local area networks (WLANs). However, the existing rate adaptation (or link adaptation) schemes for WLANs have been developed to improve the throughput of data traffic, not the quality of service (QoS) of VoIP traffic. In this paper, we investigate the characteristics of VoIP traffic and the limitations of state-of-the-art rate adaptation schemes, and then enhance the QoS of voice over WLANs (VoWLANs) by ameliorating the existing rate adaptation schemes. Specifically, we design fast decrease to control the transmission rate of retransmissions, and retry scheduling to avoid the deep fading of the wireless channel as well as hidden terminal interference. We comparatively evaluate the QoS of the revised rate adaptation schemes via ns-3 simulations and MadWiFi implementations in various communication environments, and demonstrate that the proposed scheme improves the R-score performance by up to 80% depending on the network scenarios. [ABSTRACT FROM PUBLISHER]

This paper analyzes the Quality of Service (QoS) requirements of Internet of Things (IOT). Combined with the QoS technology of the composite service, the author provides a decomposition and optimization method for the quality of the Internet of Things, and puts forward four basic QoS calculation methods. Also, the issue of QoS strategy management is discussed. [ABSTRACT FROM PUBLISHER]

Energy-efficient communication becomes increasingly important for wireless communication systems partially due to the fact that the improvement in battery technology is much slower than the increase for processing power and energy consumption of electronic devices. On the other hand, the telecommunication industry predicts that the mobile data traffic will double almost every year for the next five years with more than two thirds of the future traffic being video. Since many of the video applications are delay-sensitive, it is extremely important to consider energy-efficient design for delay-sensitive traffics over wireless systems. This paper addresses resource allocation for maximizing the energy-efficiency of a wireless link under statistical quality of service (QoS) constraints. In the energy-efficiency analysis, both circuit power and transmission power of a communication system are taken into account. The joint impact of statistical QoS constraints, transmission power, and spectral bandwidth are considered. The unique globally optimal power allocation scheme is characterized. The intuition of the optimal strategy is obtained by looking at both low signal-to-noise ratio (SNR) regime and high SNR regime. [ABSTRACT FROM PUBLISHER]

For years, wireless network systems have been trying to satisfy end-users and support high quality multimedia applications such as Mobile TV, VoIP, etc. Combining wireless networks with multimedia content distribution needs efficient routing protocols. We develop in this paper a new routing protocol, namely DOQAR (Dynamic Optimized QoE Adaptive Routing), to improve the user perception and optimize the usage of network resources. In our end-to-end model, smartphone users connect to content servers in a wired network across a wireless access network. In order to evaluate the QoE, we use a Multi-Layer Perception-based (MLP) method. Experimental results show a significant performance against other traditional routing protocols. [ABSTRACT FROM PUBLISHER]

Real-time stream quality assessment can assist network operators, content providers, streaming servers, and ISPs in evaluating their customers' quality of experience (QoE), and can lead to better design of streaming protocols, computer networks, and content delivery systems. In previous work, we demonstrated that objective data collected from an instrumented media player application can be used to predict video QoE of UDP streams with a high degree of accuracy and without the inherent scalability and interpretation issues of subjective ratings. In this paper, we extend our previous work to consider real time QoE assessment of TCP video streams, using as little as 15 seconds worth of data. By examining two video-on-demand scenarios and a general video scenario in which content changes rapidly, we find that we can accurately assign user quality ratings between 75 and 87% of the time using objective application-layer measurements from TCP video streams, such as bandwidth and frame rate, and that various combinations of stream state measurements produce accurate ratings in this range. We discuss the implications of these findings on the design of a real time video QoE assessment system.1 [ABSTRACT FROM PUBLISHER]

The concept of Quality of Service (QoS) offers different service levels to the network users. Through Service Level Specifications (SLSs), the users in a wireless network, which supports QoS, are able to express, at run-time, their expected service requirements through well defined parameters. Conventional QoS parameters, such as throughput, delay, jitter, packet loss rates, and so forth, are used for reliably ensuring a certain service level with respect to reliability and/or performance. However, most existing researches have ignored tunable security as a Quality of Service (QoS) parameter. The biggest challenge of integrating QoS and security parameters consists in their contrasting goals. This paper presents an idea to permit the users of an IEEE 802.11 Wireless Local Area Network (WLAN) to specify their security and QoS requirements in their Service Level Specifications (SLSs). Then, a game theoretic approach is presented so that the system can reach Service Level Agreement (SLA) with the users to ascertain a balanced set of security and QoS parameters for the users. The effectiveness of the proposed approach is verified through computer simulations. [ABSTRACT FROM PUBLISHER]

Wireless mesh networks (WMNs) have recently emerged as a promising technology for next-generation of wireless communications. In WMNs, admission control is deployed to control traffic loads and to prevent the wireless mesh backbone from being overloaded. Existing admission control protocols could be classified as either stateful or stateless approaches, based on network state information. Both the approaches have their limitations; the stateful models suffer from the scalability issue, while the stateless ones have the false admission problem. This paper introduces a hybrid admission control model for WMNs, based on a temporal resource reservation and three traffic regulation schemes. In particular, we propose an analytical model to compute the appropriate regulation ratio for accepted flows and to guarantee that the congestion at intermediate nodes does not exceed a threshold value. In our model, the congested node may specify the moment of session re-establishment, besides of the new rate at which the session should transmit its data packets. Using extensive simulations, we demonstrate that our model achieves high resource utilization by computing new sessions rates in a dynamic traffic-load environment, and by satisfying the quality of service (QoS) constraints in terms of delay and packets loss. [ABSTRACT FROM PUBLISHER]

Among the proposed solutions to few problems found in ad hoc networks, topology control can ensure a proper battery consumption, to avoid interference between the different nodes in the network and controlling the effect of the low transmission capacity that some nodes may show. This paper presents the results of tests using several scenarios with different transmission power levels, designed and implemented with OMNeT++. It assessed the average consumption of energy by the nodes, the network frames with interference, the average of backoff and the number of frames received. This allowed seeing the positive impact of the use of topology control on the network. [ABSTRACT FROM PUBLISHER]

The IEEE 802.16 standard is defined to meet the high-speed and wide-range data transmission in an efficient way. This paper studies the scheduling problem on IEEE 802.16e mesh networks to minimize the energy consumption of mobile stations so as to maximize the network lifetime. We consider the real-time connections and focus on the resource scheduling which includes time slots allocation, QoS guarantee of real-time flows, interference-free on each link, and spectral reuse for the channel. The proposed energy-aware link scheduling algorithms construct a mathematical model of the energy consumption problem and provide a computationally efficient scheme to solve the optimization problem. Comparing with traditional scheduling schemes for real-time flows, simulation results show that the proposed scheme significantly improves the life cycle of mobile stations. [ABSTRACT FROM PUBLISHER]

Availability of several web services having a similar functionality has led to using quality of service (QoS) attributes to support services selection and management. To improve these operations and be performed proactively, time series ARIMA models have been used to forecast the future QoS values. However, the problem is that in this extremely dynamic context the observed QoS measures are characterized by a high volatility and time-varying variation to the extent that existing ARIMA models cannot guarantee accurate QoS forecasting where these models are based on a homogeneity (constant variation over time) assumption, which can introduce critical problems such as proactively selecting a wrong service and triggering unrequired adaptations and thus leading to follow-up failures and increased costs. To address this limitation, we propose a forecasting approach that integrates ARIMA and GARCH models to be able to capture the QoS attributes' volatility and provide accurate forecasts. Using QoS datasets of real-world web services we evaluate the accuracy and performance aspects of the proposed approach. Results show that the proposed approach outperforms the popular existing ARIMA models and improves the forecasting accuracy of QoS measures and violations by on average 28.7% and 15.3% respectively. [ABSTRACT FROM PUBLISHER]

The vertical handoff is highly time-sensitive in the heterogeneous wireless environment. The most available handoff decision methods are based on a few network parameters, and so the prediction of network parameters can intensely improve the efficiency of the vertical handoff. This paper focuses on improving the prediction model based on cost function. We first propose an adaptive network parameter prediction algorithm, which establishes the prediction function for each network parameter and computes the network's QoS. Then the handoff process based on network parameter prediction is present to guide the handoff execution. We prove theoretically that the proposed prediction algorithm covers the available methods. We find the proposed algorithm can keep handoff stability. The handoff decisions based on real value and prediction value are compared in the WLAN inter-network environment. The results show that the proposed prediction model can eliminate the unnecessary handoffs which caused by the performance shake of the access network, can predict evolution trends of the network parameters in the case of performance gradual change and make the terminal connect to the QoS-ensured network as soon as possible. [ABSTRACT FROM PUBLISHER]

Wireless Sensor Networks (WSNs) is a most promising method for future environmental observation. The problem of congestion in WSNs is significantly different from conventional ad-hoc networks and has not been studied to any great extent thus far. Congestion in sink bottleneck of WSNs not only causes packet loss, but also leads to excessive energy consumption. Therefore, congestion feedback and control of WSNs will improve wireless channel quality dramatically, reduce energy consumption and avoid starvation, as a result increase network efficiency. In this paper, we proposed a distributed congestion feedback algorithm innovatively named as DCCA to solve sink bottleneck problem for multi-hop WSNs, which uses queue based congestion level detection scheme in the MAC layer and then adopts hop-by-hop feedback notification scheme in the transport layer. Finally, whether forward or drop packet will be decided by each sensor node in the network layer. Therefore, the proposed DCCA is a cross-layer design philosophical approach. [ABSTRACT FROM PUBLISHER]

The most important tendency of future Internet architectures is maintaining the best Quality of Experience (QoE), which represents the subjective perception of end-users using network services with network functions such as admission control, resource management, routing, traffic control, etc. Among of them, we focus on routing mechanism driven by QoE end-users. Nowadays, most existing routing protocols have encountered NP-complete problem when trying to satisfy multi QoS constraints criteria simultaneously. With the intention for avoiding the classification problem of these multiple criteria reducing the complexity problem for the future Internet, we propose a protocol based on user QoE measurement in routing paradigm to construct an adaptive and evolutionary system. Our approach, namely QQAR (QoE Q-learning based Adaptive Routing), is based on Q-Learning, a Reinforcement Learning algorithm. QQAR uses Pseudo Subjective Quality Assessment (PSQA), a real-time QoE assessment tool based on Random Neural Network, to evaluate QoE. Experimental results showed a significant performance against over other traditional routing protocols. [ABSTRACT FROM PUBLISHER]

The provisioning of a Quality of Service (QoS) for applications requiring real-time service demands low latency, low Bit Error Rate (BER) and bounded end to end delay guarantees. Facilitating this within a Wireless Sensor Network (WSN) is Guaranteed Time slots (GTS's) activated using a beacon enabled mode and under the governance of the accepted protocol of the IEEE 802.15.4 standard. However the limitation in design of only seven GTS per superframe duration pre-determines a problem of allocation when requirements by applications in need of good QoS exceed the supply of GTS's. This results in the QoS aware traffic requiring differentiation of service in the buffer of the Personal Area Network Coordinator (PANC). A question arises as to the true ability of service dimensioning of networks without the prior knowledge of buffer allocation. In some WSN the buffer shares memory with the application and radio stack. This memory requirement will vary depending on the application. This research complements a previous paper in which the application of Decay Rate Analysis in relation to the dimensioning of buffer allocation of the various nodes was analysed using simulation and analytical methodology. The results illustrated the probability of queue occupancy for a specific application namely VoIP. This paper proposes that by employing the decay rate analysis a better understanding of buffer requirements at the PANC can be determined for different sensor applications. This analysis will further enhance the pre-deployment dimensioning of a network for greater operational efficiency and overall cost effectiveness. [ABSTRACT FROM PUBLISHER]

The quality-of-service (QoS) metrics in a wireless sensor network (WSN) of multiple sensor types depend on the performance of the network protocol layers, motivating a comprehensive cross-layer design approach to optimize QoS. Advances in energy-harvesting techniques enable increases in WSN lifetime by prolonging operation of the wireless nodes. While the primary objective of energy harvesting is to prolong network lifetime, it may cause lower values of other QoS metrics during that lifetime. From the author's previous work, cross-layer protocol interactions are represented through a set of concatenated parameters and resource levels for a real-time WSN under energy harvesting (EH-WSN). The cross-layer parameters that determine QoS values in the EH-WSN are established in terms of solutions to stochastic dynamic programming conditions derived from multivariate point-process (MVPP) models of transient information flows. Simulation results evaluate the extent to which QoS values are degraded in an EH-WSN compared to a WSN of the same structure without energy harvesting. [ABSTRACT FROM PUBLISHER]

In a Wireless Sensor Network (WSN) the provision of a Guaranteed Time Slot (GTS) in a beacon enabled mode is best suited for applications with low latency and high Quality of Service (QoS) requirements such as those of real time traffic. However the advancements in technology have dramatically increased the volume of applications which require access to this real time service provision in such areas as healthcare, asset tracking, environmental monitoring, and military projects. Each super-frame structure contains only seven GTS's with the remaining time slots provisioned for the Contention Access Period (CAP) where applications with higher tolerance of latency vie for a position to transmit data. The restrictions within the Contention Free Period (CFP) to seven time slots per superframe structure, places enormous responsibilities on the network designers to dimension networks that can guarantee a high QoS. This work plans to apply decay rate analysis to GTS provisioning. Appropriate buffer dimensioning for specific applications can be achieved by predetermining the probability of buffer capacity. This will enable adequate parameter settings to be configured within a WSN to meet all real time traffic needs. [ABSTRACT FROM PUBLISHER]

Telecommunications services in cellular networks such as 3G Telephony Audio, Video Telephony, email, ftp, http, etc. Audio Telephony have a important role of telecommunications network and the quality of these services need to be considered. The quality of each service can be measured as a Quality of Service (QoS). QoS consists of a set of parameters related to the performance of traffic on telecommunication network. The parameters for the performance of services such as Audio Telephony Telephony Service Non-Accessibility, Telephony Setup Time, Telephony Speech Quality on Call Basis, Telephony Speech Quality on sample basis, Telephony Cut-off Call Ratio and Telephony CLIP Failure Ratio. To perform the research a simulator must be created using aggregation methods, direct and passive. The data obtained from the counter and the timer of service provider will be processed with reference to Signaling Ladder Diagram (SLD) issued by the European Telecommunications Standards Institute (ETSI). Based on SLD of Audio Telephony service, there are six network elements, 76 the number of signals, and 6 parameters. Parameters that can be calculated based on the SLD on this simulator are\: Telephony Service Non-Accessibility, Telephony Setup Time, and Telephony Cut-off Call Ratio. These three parameters will also be compared and categorized based on benchmarks of world class operator. QoS measurement of telephony service in 3G networks can be done using various methods. The methods used in this research is the aggregation, active and direct. The measurements were made by first making a measurement simulator. Simulator is built using Microsoft Excel 2010 with the support of VBA (Visual Basic for Application). Measurement results from several carriers and service providers can not be reported in this paper, as it is highly confidential data. [ABSTRACT FROM PUBLISHER]

Mobile devices are often used for upload/download using the File Transfer Protocol (FTP). Performance of FTP services on 3G networks need to be measured to meet customer satisfaction. There are various types of performance, such as Network Performance, Network Performance Overall, QoE (Quality of Experience), and end-to-end QoS (Quality of Service). Research is conducted on measurement and analysis of FTP service QoS on 3G cellular networks. Measurement refers to the definition and types of QoS, topology 3G, SLD (Signalling Ladder Diagram) of upload/download on 3G networks based on references from ETSI (European Telecommunications Standards Institute) TS (Technical Specification) 102 250–2 V2.2.1 (2011–4). QoS parameters that can be correlated with the SLD upload/download are: attach failure ratio, attach setup times, PDP context activation failure ratio, PDP context activation times, service non-accessibility, setup times, IP service access failure ratio, dan IP service setup times. QoS measurement of upload/download service in 3G networks can be done using various methods. The method used in this research is the aggregation, active and direct. The measurements were made by first making a measurement simulator. Simulator is built using Microsoft Excel 2010 with the support of VBA (Visual Basic for Application). Measurement results from several carriers and service providers can not be reported in this paper, as it is highly confidential data. [ABSTRACT FROM PUBLISHER]

Along with the rapid advancement of mobile technology, mobile devices are often used for web browsing using the protocol Hypertext Transfer Protocol (HTTP). Performance of HTTP services on 3G networks need to be considered to meet customer satisfaction. There are various types of performance, such as Network Performance, Network Performance Overall, QoE (Quality of Experience), and end-to-end QoS (Quality of Service). Research is conducted on measurement and analysis of HTTP service QoS on 3G cellular networks. Measurement refers to the definition and types of QoS, topology 3G, SLD (Signalling Ladder Diagram) of web browsing on 3G networks based on references from ETSI (European Telecommunications Standards Institute) TS (Technical Specification) 102 250–2 V2.2.1 (2011–4). QoS parameters that can be correlated with the SLD web browsing are: Attach Failure Ratio, Attach Setup Time, PDP Context Activation Failure Ratio, PDP Context Activation Time, HTTP Service Non-Accessibility, HTTP Setup Time, HTTP IP-Service Access Failure Ratio, HTTP IP-Service Setup Time, HTTP Session Failure Ratio, HTTP Session Time, dan HTTP Data Transfer Cut-off Ratio. QoS measurement of web browsing service in 3G networks can be done using various methods. The methods used in this research is the aggregation, active and direct. The measurements were made by first making a measurement simulator. Simulator is built using Microsoft Excel 2010 with the support of VBA (Visual Basic for Application). Measurement results from several carriers and service providers can not be reported in this paper, as it is highly confidential data. [ABSTRACT FROM PUBLISHER]

Video streaming is the real time delivery process of video to the user's media player services. The performance of video streaming services is one of the factors to determine customer satisfaction levels. There are various types of performance: a. QoE (Quality of Experience) b. Network Performance; c. Overall Network Performance, and d. End-to-end QoS (E2E Quality of Service). We made a simulator to measure and analyze the QoS of streaming video services on 3G networks. Measurement refers to the definition and types of QoS, topology 3G, SLD (Signaling Ladder Diagram) of video streaming on 3G networks based on references from ETSI (European Telecommunications Standards Institute) TS (Technical Specification) 102250–2 V2.2.1 (2011–4) QoS parameters that can be correlated with the SLD video streaming are: Non-Streaming Service Accessibility, Service Access Time Streaming, Streaming Teardown Failure Ratio and stream Teardown Time. QoS measurement of video streaming service in 3G networks can be done using various methods. The methods used in this research is the aggregation, active and direct. The measurements were made by first making a measurement simulator. Simulator is built using Microsoft Excel 2007 with the support of VBA (Visual Basic for Application). Measurement results from several carriers and service providers can not be reported in this paper, as it is highly confidential data [ABSTRACT FROM PUBLISHER]

In order to guarantee the quality of a service that uses the Differentiated Service QoS mechanisms, knowledge and predictions about the characteristics of the network elements and the type of traffic that is used is an important resource for service providers to configure traffic parameters on Router conditioner properly. Selection of the value and type of conditioner is often not appropriate for the performance of a DiffServ network also relies on other network elements — as a result of selection and parameter values conditioner will intuitively result in inefficient network utilities. The selection must be tailored to the application of the model policy and traffic conditioning according to Service Level Agreement (SLA) between the user and the service provider. This paper offers a solution for the selection of the parameters and the type of conditioner. The simulated traffic conditioner is TSW2CM, TSW3CM, Token Bucket, srTCM, and trTCM [ABSTRACT FROM PUBLISHER]

A mobile adhoc network (MANET) is formed by a group of wireless mobile hosts or nodes without any fixed infrastructure. As there is no central control in a MANET, a mobile node itself acts as a router. A MANET may function in a stand-alone fashion or may be connected to the Internet. Undoubtedly, MANETs play a critical role in situations where a wired infrastructure is neither available nor easy to install. MANETs are found in applications such as short-term events, battlefield communications and disaster relief activities etc. Due to node mobility and scarcity of resources such as energy of nodes and bandwidth of wireless links, it is much tougher to provide QoS guarantee in MANETs. Therefore, while designing such a network we need to look out for a good Quality of Service (QoS) of it. Many approaches have been proposed for MANET QoS but very few have addressed it from the message transmission point of view. In this paper, we discuss different factors that affect QoS and also the challenges of QoS in MANET. We then propose an algorithm to enhance the QoS in mobile adhoc network depending on its type of application it is proposed for. [ABSTRACT FROM PUBLISHER]

Virtual machine (VM) is a key component of cloud computing technology. Therefore developing an optimal scheduling mechanism for balancing VM operations at cloud computing framework is an intriguing issue for cloud computing service performance. This paper presents a study to improve cloud computing systems performance based on Eucalyptus cloud platform. An optimal load balancing mechanism called EuQoS system for scheduling VMs is proposed. Extending EuQoS to accommodate real-time services, Hadoop platform is integrated into the EuQoS system. Log processing services are utilized to investigate the performance of system throughput. Experimental results indicate that the proposed EuQoS system can improve system throughput by 6.94% compared with the basic Eucalyptus platform with Hadoop mechanisms. [ABSTRACT FROM PUBLISHER]

Since Quality of Service (QoS) provisioning for multimedia traffic in integrated Wireless and Mobile Networks is becoming increasingly important objective, in this paper we are introducing a novel concept of adaptive QoS cross-layer framework. The Adaptive QoS framework is proven via novel simulation results in integrated environment with UMTS and IEEE 802.11 networks. The aim of our novel framework is presenting new module that shall provide the best QoS and lower cost for a given service using one or more wireless technologies in a given time. The analysis of simulation results has shown superior performances with high level of QoS provisioning in a variety of network conditions. The performance of Adaptive QoS algorithm is evaluated using ns-miracle augmented with our dual-mode Mobile Equipments (MEs) and with enhanced statistical analysis. [ABSTRACT FROM PUBLISHER]