Provide Quality Of Service Support Research Articles

A survey on 802.11 MAC industrial standards, architecture, security & supporting emergency traffic: Future directions

The IEEE 802.11-based Wireless Local Area Network (WLAN) has become a ubiquitous networking technology deployed around the world. IEEE 802.11 WLAN are now widely used for real-time multimedia applications (e.g. voice and video streaming) and distributed emergency services such as telemedicine, healthcare, and disaster recovery. Both time-sensitive applications and emergency traffic are not only characterized by their high bandwidth requirements, but also impose severe restrictions on end-to-end packet delays (i.e. response time), jitter (i.e. delay variance) and packet losses. In other words, time-sensitive applications and emergency services require a strict Quality of Service (QoS) guarantee. Medium Access Control (MAC) protocol is one of the key factors that influence the performance of WLANs. The IEEE 802.11e working group enhanced the 802.11 MAC to provide QoS support in WLANs. However, recent studies have shown that 802.11e Enhanced Distributed Channel Access (EDCA) standard has limitations and it neither supports strict QoS guarantee nor emergency traffic. Providing a strict QoS guarantee as well as supporting emergency traffic under high traffic loads is really a challenging task in WLANs. A thorough review of literature on QoS MAC protocols reveals that most QoS schemes have focused on either network throughput enhancement or service differentiation by adjusting Contention Window (CW) or Inter-Frame Spaces (IFS). Therefore, a research on developing techniques to provide a strict QoS guarantee as well as support for emergency traffic is required in such systems. To achieve this objective, a general understanding of WLANs is required. This paper aims introduce various key concepts of WLANs that are necessary for design, model and develop such framework. Our main contribution in this paper is the QoS for IEEE 802.11 WLAN and MAC protocols for supporting industrial emergency traffic over network and future directions.

Joint Hybrid Wavelength Conversion and Fiber Delay Line for All-Optical Core Node Modeling and Optimization Using Dynamic QoS Support

All-optical networks (AON) assured a large bandwidth, high-speed switching, and QoS (Quality of Service) support. But due to the development of applications and services, new requirements are created in terms of, specifically resource utilization and QoS provision. To meet these demands, AON enabled core node architecture with multiple wavelength converters’ types involving full range wavelength converter (FRWC) having a significant cost. To reduce the cost, a hybrid AON with composite node architecture combining wavelength converters (WC), Fiber delay line (FDL), and wavelength range (WR) are introduced. In this architecture, fixed and limited wavelength converters (FXWC, LRWC) are utilized while the FRWC converter is replaced by FDL. The proposed architecture decreased the presence and usage of WC, FDL, and WR while assuring QoS support. A lightpath cost formulation is computed based on WR, WC, and FDL enabled in the proposed node architecture to decrease converter and FDL numbers. The cost also managed the wavelength availability to ensure lightpath control and QoS support using real-time requirements, especially loss and blocking delay. The obtained results in the comparative study, conducted in the simulation work, showed that the novel approach performed better than the existing approaches. Moreover, our proposal optimized AON resources, particularly node architecture design, while providing QoS support according to the traffic parameters and requirements.

Improving Memory Efficiency in Heterogeneous MPSoCs through Row-Buffer Locality-aware Forwarding

In heterogeneous multicore systems, the memory subsystem plays a critical role, since most core-to-core communications are conducted through the main memory. Memory efficiency has a substantial impact on system performance. Although memory traffic from multimedia cores generally manifests high row-buffer locality, which is beneficial to memory efficiency, the locality is often lost as memory streams are forwarded through networks-on-chip (NoC). Previous studies have discussed the techniques that improve memory visibility to reveal scattered row-buffer hit opportunities to the memory scheduler. However, extending local memory visibility introduces little benefit after the locality has been severely diluted. As the alternative approach, preserving row-buffer locality in the NoC has not been well explored. What is worse, it remains to be studied how to perform network traffic scheduling with the awareness of both memory efficiency and quality-of-service (QoS). In this article, we propose a router design with embedded row-index caches to enable locality-aware packet forwarding. The proposed design requires minor modifications to existing router microarchitecture and can be easily implemented with priority arbiters to integrate QoS support. Extensive evaluations show that the proposed design achieves higher memory efficiency than prior memory-aware routers, in addition to providing QoS support. On basis of extant QoS-aware routers, locality-aware forwarding helps to increase row-buffer hits by 58.32% and reduce memory latency by 14.45% on average. It also introduces a net reduction in DRAM and NoC energy cost by 27.82%.

Toward OS-Level and Device-Level Cooperative Scheduling for Multitasking GPUs

As one of the most popular accelerators, the graphics processing unit (GPU) has been extensively adopted throughout the world. With the burst of new applications and the growing scale of data, co-running applications on limited GPU resources has become increasingly important due to its dramatic improvement in overall system efficiency. Quality of service (QoS) support among concurrent general-purpose GPU (GPGPU) applications is currently one of the most trending research topics. Prior efforts have been focused on providing QoS support either with OS-level or device-level scheduling methods. Each of these scheduling methods possesses pros and cons and may be unable to independently cover all the scheduling cases. In this paper, we propose a cooperative QoS scheduling scheme (C-QoS) that consists of operating-system-level (OS-level) scheduling and device-level scheduling. Our proposed scheme can control the progress of a kernel and provide thorough QoS support for concurrent applications in multitasking GPUs. Due to the accurate resource management of the copy engine and execution engine, C-QoS achieves QoS goals 23.33% more often than state-of-the-art QoS support mechanisms. The results demonstrate that cooperative methods achieve 17.27% higher system utilization than uncooperative methods.

Intra-flow Contention Scheme for Improving QoS in WLAN

With the increasing popularity of wireless local area network(WLAN),the demand for multimedia services encompassing VoIP, multimedia streaming and interactive gaming is increasing rapidly. The real-time services require stringent Quality of Service (QoS) guarantees for effective communication. While a lot of research has dealt with providing QoS support for real-time services in traditional wired networks, the shared and broadcast nature of the wireless medium necessitates the design of new solutions for wireless networks. In wireless networks, unlike wired networks, the communication from one node will consume the bandwidth of the neighboring nodes and hence the shared bandwidth can be easily over-utilized. Therefore, to provide an acceptable level of QoS for the real-time services, it is necessary to control the utilization of the shared bandwidth. In this paper , we propose an efficient admission control scheme named Intra-flow contention scheme with CAC-OLSR routing protocol for WLAN networks which aims at preserving the QoS for all the admitted flows by employing a low overhead threshold mechanism. We describe several alternatives for the design of IAC and compare the performance of these alternatives using simulation results.

An Adaptive Cross-Layer Architecture to Optimize QoS Provisioning in MANET

<p>Mobile Ad Hoc Network (MANET) is a collection of mobile nodes, which dynamically form a temporary network, without using any infrastructure like wireless access points or base-stations. The provision of QoS guarantees is much more challenging in Mobile Ad hoc Networks. There are many interesting applications such as multimedia services, disaster recovery etc can be supported if Quality-of-Service (QoS) support can be provided for MANETs. But QoS provisioning in MANETs is a very challenging problem when compared to wired IP networks. This is because of unpredictable node mobility, wireless multi-hop communication, contention for wireless channel access, limited battery power and range of mobile devices as well as the absence of a central coordination authority. So, the design of an efficient and reliable routing scheme providing QoS support for such applications is a difficult task. In this paper we studied the challenges and approaches for QoS aware routing techniques. </p><p> </p>

Quality of service management for intelligent systems

A control application requirements currently used is very low, such as packet loss rate, minimum delay on sensor networks with quality of service (QoS) requirements some packet delivery guarantee. This paper is the sampling period at the end of the actuator and sensor data transfer related to the Miss ratio for each source sensor node, use the controller and the internal ANFIS. The proposed scheme has the advantages of simplicity, scalability, and General. Simulation results of the proposed scheme can provide QoS support in WSANs.

On-demand QoS and Stability Based Multicast Routing in Mobile Ad Hoc Networks

Finding a connection path that remains stable for suciently longer period is critical in mobile ad hoc networks due to frequent link breaks. In this paper, an on-demand Quality of Service (QoS) and stability based multicast routing (OQSMR) scheme is proposed, which is an extension of ad hoc on-demand multicast routing protocol (ODMRP) to provide QoS support for real time applications. The scheme works as follows. Each node in the network periodically estimates the parameters, i.e., node and link stability factor, bandwidth availability, and delays. Next step is creation of neighbor stability and QoS database at every node by using estimated parameters. The last sequence is multicast path construction by using, route request and route reply packets, and QoS and stability information, i.e., link/node stability factor, bandwidth and delays in route information cache of nodes, and performing route maintenance in case of node mobility and route failures. The simulation results indicate that proposed OQSMR demonstrates reduction in packet overhead, improvement in Packet Delivery Ratio (PDR), and reduction in end-to-end delays as compared to ODMRP, and Enhanced ODMRP (E-ODMRP).

Joint Topology-Transparent Scheduling and QoS Routing in Ad Hoc Networks

This paper considers the problem of joint topologytransparent scheduling (TTS) and quality-of-service (QoS) routing in ad hoc networks and presents a joint scheme for the problem. Due to its ability to guarantee single-hop QoS support, TTS is chosen as the underlying medium-access-control (MAC) protocol. By being built on top of TTS, this paper first designs methods for bandwidth estimation and allocation (BWE and BWA, respectively) to provide QoS support without knowledge of slot status information, and then, estimates and allocates nonassigned eligible bandwidth for best effort (BE) flows. With these bandwidth management methods, this paper proposes a QoS routing protocol for a mixture of QoS and BE flows. Idealized simulation results based on the standard radio model, which ignores external sources of radio interference and protocol inefficiencies, reveal that the proposed joint scheme can provide a reduction of at least 93% in QoS violation rates and a reduction of 78%-89% in control overhead compared with the conventional dynamic source routing (DSR)/IEEE 802.11 technique. A comparison with another conventional technique, i.e., DSR/carrier sense multiple access (CSMA), also reveals that the proposed joint scheme can reduce QoS violation rates by at least 93%. In addition, the proposed joint scheme can provide an increase of 31%-104% in aggregate throughput over two representative QoS routing protocols while achieving a reduction of approximately 93% in QoS violation rates. The performance improvement to be achieved under a realistic radio model is yet to be determined.

Admission control in wireless ad hoc networks: a survey

Abstract Wireless mobile ad hoc networks (MANETs) have emerged as a key technology for next-generation wireless networking. Because of their advantages over other wireless networks, MANETs are undergoing rapid progress and inspiring numerous applications. However, many technical issues are still facing the deployment of this technology, and one of the most challenging aspects is the quality of service (QoS) provisioning for multimedia real-time applications. MANETs are expected to offer a diverse range of services to support real-time traffic and conventional data in an integrated fashion. Because of the diversified QoS requirements of these services, QoS models are needed for an efficient usage of network resources. One of the most crucial mechanisms for providing QoS support is admission control (AC). AC has the task of estimating the state of network's resources and thereby to decide which application data flows can be admitted without promising more resources than are available and thus violating previously made guarantees. In order to provide a better understanding of the AC research challenges in MANETs, this paper presents a detailed investigation of current state-of-the-art AC models in ad hoc networks. A brief outline of the admission function, feedback to route failures, as well as the advantages and drawbacks of each discussed model are given.

Distributed admission control protocol for end-to-end QoS assurance in ad hoc wireless networks

Abstract To reserve end-to-end bandwidth in quality of service (QoS) supported wireless ad hoc networks, local bandwidth requirement should be carefully determined by considering the number of contending nodes in an interference range. In this article, we propose a novel admission control protocol, called DACP (distributed admission control protocol), which is implemented over a reactive ad hoc routing protocol with minimal overhead. DACP computes the required bandwidth for end-to-end band-width provision at each node and estimates the available bandwidth at the medium access control layer. After that, DACP makes a decision for admitting a flow in a per-hop basis. Extensive simulations are carried out via the OPNET simulator. The simulation results demonstrate that DACP not only provides guaranteed end-to-end resource but also reduces the control overhead to provide QoS support, compared with the existing admission control schemes.

Providing QoS support through scheduling in WiMAX systems

The WiMAX system outlines support for quality of service (QoS) through several service classes differentiation. However, no specific scheduling has been defined to carry the task. In this paper, we propose a simple and standard-compliant scheduling algorithm for downlink and uplink connections. The proposed algorithm calculates and grants the needed resources in terms of slots based on the QoS requirements and the priority of the service classes. The simulation results show that the scheduling algorithm has fulfilled the QoS provisions of all service classes of WiMAX system in terms of delay and throughput requirements.

QoS-aware MAC protocols for wireless sensor networks: A survey

The adoption of wireless sensor networks by applications that require complex operations, ranging from health care to industrial monitoring, has brought forward a new challenge of fulfilling the quality of service (QoS) requirements of these applications. However, providing QoS support is a challenging issue due to highly resource constrained nature of sensor nodes, unreliable wireless links and harsh operation environments. In this paper, we focus on the QoS support at the MAC layer which forms the basis of communication stack and has the ability to tune key QoS-specific parameters, such as duty cycle of the sensor devices. We explore QoS challenges and perspectives for wireless sensor networks, survey the QoS mechanisms and classify the state of the art QoS-aware MAC protocols together with discussing their advantages and disadvantages. According to this survey, we observe that instead of providing deterministic QoS guarantees, majority of the protocols follow a service differentiation approach by classifying the data packets according to their type (or classes) and packets from different classes are treated according to their requirements by tuning the associated network parameters at the MAC layer. Design tradeoffs and open research issues are also investigated to point out the further possible research directions in the field of QoS provisioning in wireless sensor networks at the MAC layer.

Impairment-aware QoS provisioning in dual-header OBS networks

Signal degradation due to physical impairments may result in unacceptable bit-error rates of received signals at the destination. Based on earlier work, we study the impairment-aware quality of service (QoS) provisioning problem in dual-header optical burst switching (OBS) networks that employ two control packets for each data burst. At an OBS node, the proposed algorithm schedule bursts for transmission by searching for available resources using admission control and preemption. The algorithm also verifies signal quality. Simulation results show that this algorithm is effective in providing QoS support in OBS networks while considering physical impairment effects.

Cross-layer QoS support framework and holistic opportunistic scheduling for QoS in single carrier WiMAX system

Providing Quality of Service (QoS) to different service classes with real-time and non-real-time traffic integration is an important issue in WiMAX systems. Opportunistic MAC (OMAC) is a novel view of communication over spatiotemporally varying wireless links. It combines the features of a cross-layer design and an opportunistic scheduling scheme to achieve high utilization while providing QoS to various applications. Channel characteristics, traffic characteristics and queue characteristics are essential factors in the design of opportunistic scheduling algorithms. In this paper, we propose a cross-layer QoS support scheduling framework and a corresponding opportunistic scheduling algorithm to provide QoS support to the heterogeneous traffic in single carrier WiMAX point-to-multipoint (PMP) systems. We model the uplink transmission in the single carrier WiMAX system as a multi-class priority TDMA queueing system to analyze the average packet delays of different service classes. Extensive simulation experiments have been carried out to evaluate the performance of our proposal. The simulation results show that our proposed solution can improve the performance of the WiMAX PMP system in terms of packet loss rate, packet delay and system throughput.

A Model-Based Downlink Resource Allocation Framework for IEEE 802.16e Mobile WiMAX Systems

In this paper, we propose a novel model-based resource allocation framework to provide quality-of-service (QoS) support in the downlink (DL) of an IEEE 802.16e mobile WiMAX system. First, we develop a queueing model that links important performance measures of DL service flows to a set of tunable parameters. Based on the queueing model, we show how these parameters could be set to appropriate values to meet the QoS performances sought by admitted service flows. We then introduce a resource allocation scheme that uses these parameter values in packet scheduling decisions. In this queue- and channel-aware scheme, the queue-length-based packet scheduler is complemented by a cross-layer orthogonal frequency-division multiple access (OFDMA) slot allocation mechanism that adapts to channel conditions at the destination mobile stations (MSs). Compared with existing schemes, the proposed scheme is compatible with the updated definition of some key resource allocation concepts in IEEE 802.16e and offers a simple yet more effective way to provide QoS to a heterogeneous mix of applications. Its cross-layer aspect ensures efficient resource utilization in the presence of link adaptations due to mobility and channel fading. It also offers greater flexibility to service providers by allowing probabilistic delay guarantees to delay-sensitive multimedia applications. Simulation results show the performance benefits of the proposed scheme in providing QoS support for both real-time and non-real-time applications in mobile WiMAX systems.

A Novel QoS Multipath Path Routing in MANET

Mobile ad hoc networks are typically characterized by high mobility and frequent link failures that result in low throughput and high end-to-end delay. The increasing use of MANETs for transferring multimedia applications such as voice, video and data, leads to the need to provide QoS support. We introduce a routing algorithm, Ad hoc on-demand multipath routing, which provides quality of service (QoS) support,(Q-AOMDV) in terms of bandwidth, hop count and end-to-end delay in mobile ad hoc networks. The results validate that Q-AOMDV provides QoS support in mobile ad hoc wireless networks with high reliability and low overhead..

Cross-Layer MAC Protocol and Holistic Opportunistic Scheduling with Adaptive Power Control for QoS in WiMAX

Providing quality of service (QoS) to different service classes with integrated real-time and non-real-time traffic is an important issue in broadband wireless access networks. Opportunistic MAC (OMAC) is a novel view of communication over spatiotemporally varying wireless link whereby the multi-user diversity is exploited rather than combated to maximize bandwidth efficiency or system throughput. It combines cross-layer design features and opportunistic scheduling scheme to achieve high utilization while providing QoS support to various applications. Channel characteristics, traffic characteristics and queue characteristics are the essential factors in the design of opportunistic scheduling algorithms. In this paper, we propose a cross-layer MAC scheduling framework in WiMAX point-to-multipoint (PMP) systems and a corresponding opportunistic scheduling algorithm with an adaptive power control scheme to provide QoS support to the heterogeneous traffic. Extensive simulation experiments have been carried out to evaluate the performance of our proposal. The simulation results show that our proposed solution can improve the performance of the WiMAX PMP systems in terms of packet loss rate, packet delay and system throughput.

Quality of Service (QoS) Provisions in Wireless Sensor Networks and Related Challenges

Wireless sensor networks (WSNs) are required to provide different levels of Quality of Services (QoS) based on the type of applications. Providing QoS support in wireless sensor networks is an emerging area of research. Due to resource constraints like processing power, memory, bandwidth and power sources in sensor networks, QoS support in WSNs is a challenging task. In this paper, we discuss the QoS requirements in WSNs and present a survey of some of the QoS aware routing techniques in WSNs. We also explore the middleware approaches for QoS support in WSNs and finally, highlight some open issues and future direction of research for providing QoS in WSNs.

WMN QoS routing strategy based on interference model

To support multimedia applications in Wireless Mesh Networks(WMN),the authors proposed an interference-based Quality-of-Service(QoS) routing strategy named WQRI.This strategy first stratified WMN and then proposed novel methods to estimate the available bandwidth and end-to-end delay.It achieved reliable admission control and resource reservation.Simulation results indicate that WQRI can provide QoS support for real-time applications at lower control packet overhead.