Adaptive Drop Tail: An Algorithm for maintaining delay bounds in a buffer with time-varying arrival rate

The relationship between the user perceived Quality of Experience (QoE) with Internet applications and the Quality of Service (QoS) of the underlying network and applications is complex. Unveiling statistical relations between QoE and QoS can boost the prediction and diagnosis of QoE. In this paper, we shed light on the relationship between QoE and QoS for a popular application: YouTube video streaming. We conducted a controlled study where we asked users to rate their perceived quality of YouTube videos under different network conditions. During this experiments, we also captured network QoS and application QoS. We then analyze the resulting dataset with SES, a feature selection algorithm that identifies multiple, minimal-size, statistically-equivalent signatures with maximal predictive power for a target variable (e.g., QoE). We found that we can build optimal QoE predictors using a minimal signature of only three features from application or network QoS metrics compared to four when we consider features from both layers.

The IEEE 802.11n supports high data rate transmissions due its physical layer Multiple Input ‎Multiple Output (MIMO) advanced antenna system and MAC layer enhancement features (frame ‎aggregation and block acknowledgement). As a result this standard is very suitable for multimedia ‎services through its Enhanced Distributed Channel Access (EDCA). This paper focuses on ‎evaluating the Quality of Service (QoS) application on the performance of the IEEE 802.11n ‎random topology WLAN. Three different number of nodes (3, 9 and 18) random topology with one ‎access point are modeled and simulated by using the Riverbed OPNET 17.5 Modular to ‎investigate the Wireless Local Area Network (WLAN) performance for different spatial streams. ‎The result clarified the impact of QoS application and showed that its effect is best at the 18 node ‎number topology. For a 4x4 MIMO, when QoS is applied and with respect to the no QoS ‎application case, simulation results show a maximum improvement of 86.4%, 33.9%, 52.2% and ‎‎68.9% for throughput, delay, data drop and retransmission attempts, respectively. ‎

The authors consider an M/G/1 queue with a time-varying arrival rate. The objective is to obtain infinitesimal perturbation analysis (IPA) gradient estimates for various performance measures of interest with respect to certain system parameters. In particular, the authors consider the mean system time over n arrivals and an arrival rate alternating between two values. By choosing a convenient sample path representation of this system, they derive an unbiased IPA gradient estimator which, however, is not consistent, and investigate the nature of this problem. >

Providing quality of service (QoS) for real-time multimedia applications such as video streaming in mobile ad hoc networks (MANETs) is an important challenge. MANETs are characterized by lack of fixed infrastructure, dynamic topology, and limited resources that make more difficult multimedia applications transport and run on this networks. To overcome this challenge, video coding techniques combined to multiple routing paths (multipath) is a promising technique for supporting transmission of multiple video streams with appropriate QoS over mobile ad hoc networks. In this paper, firstly, many issues and different techniques for video streaming over MANET have been reviewed and secondly two multi paths routing protocols (M-AODV and MDSDV) have been evaluated in order to improve QoS for real-time multimedia applications. Results show that none of these two protocols is better than the other. In certain situations (throughput and load network with high mobility) is M-AODV but in others (network load and reliability for large-scale network) is MDSDV protocol which displays good performance. It is also noted that these two protocols provide between acceptable and good quality and a small jitter regardless of nodes number in medium mobility.

Data centers consume significant amounts of energy, contributing indirectly to environmental pollution through greenhouse gas emissions during electricity generation. According to the Natural Resources Defense Council, information and communication technologies and networks account for roughly 10% of global energy consumption. Reducing power consumption in Data Center Networks (DCNs) is crucial, especially given that many data center components operate at full capacity even under low traffic conditions, resulting in high costs for both service providers and consumers. Current solutions often prioritize power optimization without considering Quality of Service (QoS). Services such as video streaming and Voice over IP (VoIP) are particularly sensitive to loss or delay and require QoS to be maintained below certain thresholds. This paper introduces a novel framework called QoS-Aware Power-Optimized Path Selection (Q-PoPS) for software-defined DCNs. The objective of Q-PoPS is to minimize DCN power consumption while ensuring that an acceptable QoS is provided, meeting the requirements of DCN services. This paper describes the implementation of a prototype for the Q-PoPS framework that leverages the POX Software-Defined Networking (SDN) controller. The performance of the prototype is evaluated using the Mininet emulator. Our findings demonstrate the performance of the proposed Q-PoPS algorithm in three scenarios. Best-case: Enhancing real-time traffic protocol quality without increasing power consumption. midrange-case: Replacing bottleneck links while preserving real-time traffic quality. Worst-case: Identifying new paths that may increase power consumption but maintain real-time traffic quality. This paper underscores the need for a holistic approach to DCN management, optimizing both power consumption and QoS for critical real-time applications. We present the Q-PoPS framework as evidence that such an approach is achievable.

The idea behind the proposition of Networks-on-Chip (NoCs) for modern and future systems on chip capitalizes on the fact that busses do not scale well when shared by a large number of cores. Even if NoC research is a relatively young field, the literature abounds with propositions of NoC architectures. Several of these propositions claim providing quality of service (QoS) guarantees, which is essential for real time and multimedia applications. The most widespread approach to attain some degree of QoS guarantee relies on a two-step process. The first step is to characterize application performance through traffic modeling and simulation. The second step consists in tuning a given network template to achieve some degree of QoS guarantee. These QoS targeted NoC templates usually provide specialized structures to allow either the creation of connections (circuit switching) or the assignment of priorities to connectionless flows. It is possible to identify three drawbacks in this two-step process approach. First, it is not possible to guarantee QoS for new applications expected to run on the system, if those are defined after the network design phase. Second, even with end-to-end delay guarantees, connectionless approaches may introduce jitter. Third, to model traffic precisely for a complex application is a very hard task. If this problem is tackled by oversimplifying the modeling phase, errors may arise, leading to NoC parameterization that is poorly adapted to achieve the required QoS. This Chapter has two main objectives. The first one is to evaluate the area-performance trade-off and the limitations of circuit switching and priority scheduling to meet QoS. This evaluation will show where such implementations are really suited for QoS, and when more elaborate mechanisms to meet QoS are needed. The second objective comprises proposing a method, called rate-based scheduling, to approach QoS requirements considering the execution time state of the NoC. The evaluation of circuit switching and priority scheduling show that: (i) circuit switching can guarantee QoS only to a small number of flows; the technique do not scale well, and can potentially waste significant bandwidth; (ii) priority-based approaches may display best-effort behavior and, in worst-case situations, may lead to unacceptable latency for low priority flows, besides being subject to jitter. In face of these limitations, rate-based scheduling arises as an option to improve the performance of QoS flows when varying traffic scenarios are used.

The distributed resource controller (DRC) technology described in this paper provides a novel approach to interfacing applications with emerging network mechanisms to deliver quality of service (QoS) and controlling network resource utilization. DRC aims to unify network services (e.g., Diffserv, Intserv, and ATM) and application QoS provisioning by introducing a middleware system and a set of generic interfaces. DRC middleware is the core part that translates application requests for QoS delivery into respective access to underlying network systems in a manner that optimizes resource utilization and shelters applications from such a complexity. Applications can request QoS to the DRC middleware in two ways: either on-line using the DRC QoS API or off-line via the DRC utility. Application QoS requirements are specified in terms of two categories of parameters: traffic profile (quantitative) and user expectation (qualitative). DRC currently uses the CORBA-based object-oriented technology to develop a CORBA-based resource controller (CRC). The working CRC prototype built to manage the integrated services is also presented.

To analyze networks of queues, it is important to be able to analyze departure processes from single queues. For the M/M/s and M/G/∞ models, the stationary departure process is simple (Poisson), but in general the stationary departure process is quite complicated. As a basis for approximations, this paper shows that the stationary departure process is approximately Poisson when there are many busy slow servers in a large class of stationary G/GI/s congestion models having s servers, infinite waiting room, the first-come first-served discipline, and mutually independent and identically distributed service times that are independent of a stationary arrival process. Limit theorems are proved for the departure process in a G/GI/s system in which the number of servers and the offered load (arrival rate divided by the service rate) both increase. The asymptotic behavior of the departure process depends on the way the arrival rate changes. If the arrival rate is held fixed, so that the offered load increases by slowing down the service rate, then the departure process converges to a Poisson process. For this result, the service-time distribution is assumed to be phase-type. Other limiting behavior occurs if the arrival rate approaches zero or infinity. Convergence is established in each case by applying previous heavy-traffic limit theorems.

A queueing model of the Markov-modulated Poisson process (MMPP) with thresholds was investigated. The customer arrival with various arrival rates in the model was viewed as the MMPP. In contrast to the Poisson’s arrival process, the MMPP can better describe the situation that the arrival rate changes with changing conditions; therefore, the model fits better with reality. The threshold conversion was added to the model based on the general MMPP/M/C model. When the number of customers in the system exceeds a threshold, all servers work to serve; when the number of customers in the system is less than another threshold, some servers are shut down. This is the congestion-based staffing policy with two thresholds. Specifically, the problems in the slab stocking stage of slab production at the Iron and Steel Complex in China were analysed. In the slab production process, because the rate of the upstream steelmaking is not constant, the rate of slab reaching the slab yard is uncertain. The crane service is used to store slabs in a warehouse. Because the slab arrival rate varies, different numbers of cranes in service need to be optimized for cost control. Thus, MMPP was used to describe slab arrival with varied arrival rates. Therefore, an MMPP/M/C queue with thresholds was used to analyse and solve the practical problems, and the optimal number of service cranes was obtained to minimize the cost of slab stocking.

Software-Defined Networking (SDN) is a new efficiently idea of programmable networks that separates the control plane from data plane of all network devices. Internet service provider is responsible for all the control decisions and communication among the forwarding elements from centralized controller. SDN provides the various optimized services. Quality of service (QoS) routing is a path computation method that is suitable for the different traffics generated by several applications, while utilization of network resources has increased. This agreement of service is defined by QoS requirements such as throughput, delay, jitter and packet loss etc. Multimedia applications often require assured from multi QoS constrained, causing the NP-complete problem which cannot be simply solved in polynomial time and high management complexity in the transition network. SDN is able to reduce complexity and it is used to efficiently implement traffic, hence SDN significantly values to development QoS routing. In this paper, we propose QoS routing algorithm called Quantized Level Balance (QLB) for SDN that considers one or many QoS parameters relating to the network application. To satisfy the requirements, QLB selects QoS parameters depending to the level of appropriate application service quality. We have replicated our algorithm on simulate topology with Scalable Video-streaming Evaluation Framework (SVEF). We measure the Peak Signal-to-Noise Ratio (PSNR) and Mean Opinion Score (MOS) of Scalable Video Coding (SVC) at the receiver. Our propose algorithm is improved than single-metric approach that may choose poor QoS parameter paths.

Vehicular ad hoc network (VANET) is an emerging network technology with the goal of providing public safety, traffic coordination and infotainment for the comfort of passengers in moving vehicles. However, it faces the challenge of not providing the expected quality of service (QoS) when streaming videos online. This challenge emanate from the variable topology infrastructure caused by intrinsic high mobility nodes and dynamic environments of VANETs. A better QoS in video applications can possibly be achieved if suitable routing protocols (RPs) is/are used. Hence, this paper compared and analyzed four existing routing protocols in VANETs. The objective was to identify an efficient RPs that can deliver better QoS for video streaming applications with respect to number of nodes used. A simulation was conducted using OPNET 14.5 Modeler and results analyzed with respect to throughput, delay and routing traffic received. Results shows that OLSR performance is better when few nodes are used and AODV shows better service when many nodes are used, thereby guaranteeing the user high quality of video when streaming online. Based on the results, it would be recommended that OLSR and AODV be used as hybrid protocol to provide better QoS for video streaming in VANETs.

Network slicing is a technology that virtualizes a single infrastructure into multiple logical networks (called slices) where resources or virtualized functions can be flexibly configured by demands of applications to satisfy their quality of service (QoS) requirements. Generally, to provide the guaranteed QoS in applications, resources of slices are isolated. In wired networks, this resource isolation is enabled by allocating dedicated data bandwidths to slices. However, in wireless networks, resource isolation may be challenging because the interference between links affects the actual bandwidths of slices and degrades their QoS. In this paper, we propose a slice management scheme that mitigates the interference imposed on each slice according to their priorities by determining routes of flows with a different routing policy. Traffic flows in the slice with the highest priority are routed into shortest paths. In each lower-priority slice, the routing of traffic flows is conducted while minimizing a weighted summation of interference to other slices. Since higher-priority slices have higher interference weights, they receive lower interference from other slices. As a result, the QoS of slices is differentiated according to their priorities while the interference imposed on slices is reduced. We compared the proposed slice management scheme with a naïve slice management (NSM) method that differentiates QoS among slices by priority queuing. We conducted some simulations and the simulation results show that our proposed management scheme not only differentiates the QoS of slices according to their priorities but also enhances the average throughput and delay performance of slices remarkably compared to that of the NSM method. The simulations were conducted in grid network topologies with 16 and 100 nodes and a random network topology with 200 nodes. Simulation results indicate that the proposed slice management increased the average throughput of slices up to 6%, 13%, and 7% and reduced the average delay of slices up to 14%, 15%, and 11% in comparison with the NSM method.

. The purpose of this research is to investigate the implementation and application of service quality by the expedition service of JNE, to determine the response of consumers regarding the implementation of service quality by the JNE, and to find out how much influence the service quality to consumers satisfying. This research was conducted at the JNE’s company with the case study method and using simple regression analysis were processed with SPSS.The sample which is taken are consumers of JNE by the number of 100 respondents. With the research methods of survey and sampling techniques are non-probability sampling. Analysis of data used is simple regression analysis aimed to test the hypothesis.The results of this study show the influence service quality on consumer satisfying with a value of p = 0.000, correlation coefficient of 0,711 (R = 0,711), and the determinant coefficient (R-Square / R2) of 50.6%. This means that there is influence between service quality to consumers satisfying. Keywords : Service Quality, Consumer Satisfying.

Several propositions of NoC architectures claim to provide quality of service (QoS) guarantees, which is essential for e.g. real time and multimedia applications. The most widespread approach to attain some degree of QoS guarantee relies on a two-step process. The first step is to characterize application performance through traffic modeling and simulation. The second step consists in tuning a given network template to achieve some degree of QoS guarantee. These QoS targeted NoC templates usually provide specialized structures to allow either the creation of connections (circuit switching) or the assignment of priorities to connectionless flows. It is possible to identify three drawbacks in this approach. First, it is not possible to guarantee QoS for new applications expected to run on the system, if those are defined after the network design phase. Second, even with end-to-end delay guarantees, connectionless approaches introduce jitter. Third, to model traffic precisely for a complex application is a very hard task. The objective of this paper is to evaluate the area-performance trade-off and the limitations of circuit switching and priority scheduling to meet QoS. Preliminary results show the need of more research in this field, by considering the aggregation of more explicit techniques to control QoS

Emerging web applications (e.g., video streaming and Web of Things applications) account for a large share of traffic in Wide Area Networks (WANs) and provide traffic with various Quality of Service (QoS) requirements. Software-Defined Wide Area Networks (SD-WANs) offer a promising opportunity to enhance the performance of Traffic Engineering (TE), which aims to enable differentiable QoS for numerous web applications. Nevertheless, SD-WANs are managed by controllers, and unpredictable controller failures may undermine flexible network management. Switches previously controlled by the failed controllers may become offline, and flows traversing these offline switches lose the path programmability to route flows on available forwarding paths. Thus, these offline flows cannot be routed/rerouted on previous paths to accommodate potential traffic variations, leading to severe TE performance degradation. Existing recovery solutions reassign offline switches to other active controllers to recover the degraded path programmability but fail to promise good TE performance since higher path programmability does not necessarily guarantee satisfactory TE performance. In this paper, we propose ARES to provide predictable TE performance under controller failures. We formulate an optimization problem to maintain predictable TE performance by jointly considering fine-grained flow-controller reassignment using P4 Runtime and flow rerouting and propose ARES to efficiently solve this problem. Extensive simulation results demonstrate that our problem formulation exhibits comparable load balancing performance to optimal TE solution without controller failures, and the proposed ARES significantly improves average load balancing performance by up to 43.36% with low computation time compared with existing solutions.