QoS Support Research Articles

Resource management for QoS support in cognitive radio networks

Cognitive radio technology is a key enabler to reuse a finite, scarce, and expensive resource: the radio spectrum. Guaranteeing required levels of QoS to cognitive users and ensuring necessary protection to incumbent users are the two main challenges in opportunistic spectrum access. This article identifies the main requirements and challenges for QoS support in cognitive radio networks. A framework for a twofold cognitive manager is presented; one part managing spectrum availability on longer timescales and the other handling resource management on shorter timescales. This article gives particular focus to the functionalities of the latter cognitive manager related to resource management. Finally, we present a few key scenarios and describe how QoS can be managed with the proposed approach without disturbing the communications of incumbent users.

DAElite: A TDM NoC Supporting QoS, Multicast, and Fast Connection Set-Up

Networks-on-Chip (NoC) are seen as promising interconnect solutions, offering the advantages of scalability and high-frequency operation which the traditional bus interconnects lack. Several NoC implementations have been presented in the literature, some of them having mature tool-flows. The main differentiating factor between the various implementations is the set of services and communication patterns they offer to the end-user. In this paper we present dAElite, a TDM Network-on-Chip that offers a unique combination of features, namely, guaranteed bandwidth and latency per connection, built-in support for multicast, and a short connection set-up time. While our NoC was designed from the ground up, we leverage on existing tools for network dimensioning, analysis, and instantiation. We have implemented and tested our proposal in hardware and we compared it to AEthereal, a state-of-the-art NoC with similar features, but no multicast. We find that the connection set-up time is reduced by a factor of 10 and the network traversal latency is decreased by 33 percent. Moreover, considering realistic values of the network parameters, dAElite has a lower hardware area when synthesized in 65 nm technology.

Efficient QoS provisioning at the MAC layer in heterogeneous wireless sensor networks

New emerging applications for wireless sensor networks, such as mission-critical and multimedia applications, require sensing heterogeneous phenomena, and that the network supports different types of QoS-constrained traffic at variable rates. Designing an efficient medium access control protocol allowing these applications to work properly while coping with the limited resources of sensor networks is a challenging task. In this paper, we present a new adaptive MAC protocol with QoS support for heterogeneous wireless sensor networks which provides high channel utilization with a hybrid and adaptive behavior, and integrates a new efficient prioritization scheme to provide QoS support and fair data delivery of heterogeneous traffic. The protocol design is presented along with performance results obtained through extensive simulations. A mathematical model is provided and applied to perform an analytical evaluation of AMPH. Performance modeling, analysis, and simulation results show the effectiveness of our solution.

Frequency resource allocation strategy with QoS support in hybrid cellular and Device‐to‐Device networks

SummaryHybrid networks, comprising a conventional cellular network overlaid with Device‐to‐Device (D2D), offer efficient way to improve system throughput. In this paper, a novel orthogonal frequency‐division multiple access channel‐assignment method is proposed for hybrid network. The proposed approach is optimal in terms of throughput and is subjected to a sensible QoS requirement, which guarantees that macrocell and D2D achieve a prescribed data rate and outage probability, respectively. Our solution consists of two phases. In the first phase, the minimum sub‐channels are allocated to the macrocell to satisfy their data rate requirements. This problem is mapped to the 0‐1 Knapsack Problem and solved by integer programming based Lagrange dual approach. In the second phase, the redundant sub‐channels are allocated to D2D pairs to maximize the throughput of D2D networks. An interference management scheme is proposed to guarantee the outage probability of D2D communications. A cluster is taken as the unit for frequency reuse among D2D pairs. The problem of clustering is mapped to the MAX k‐CUT problem in graph theory and is solved by graph‐based heuristic algorithm. Extensive simulations demonstrate the superior performance of the proposed solution compared with the existing scheme. Copyright © 2014 John Wiley & Sons, Ltd.

End-to-end delay differentiation mechanism for integrated EPON–WiMAX networks

For integration of Ethernet passive optical network and IEEE 802.16 WiMAX, it is imperative to provide end-to-end quality of service due to the heterogeneous MAC nature of EPON and WiMAX. To address this issue, this paper proposes a QoS-enabled transmission mechanism operated on a specially devised hybrid optical network unit-base station architecture for QoS support, especially delay differentiation, between EPON and WiMAX. Simulation results show that the proposed scheme outperforms the existing transmission mechanisms in terms of the end-to-end delay and jitter, due to its QoS continuity between them.

Delay Analysis of Converged Optical- Wireless Networks with QoS Support

Delay Analysis of Converged Optical- Wireless Networks with QoS Support

Virtual Machine Resource Allocation for Multimedia Cloud: A Nash Bargaining Approach

Recently, multimedia cloud is being considered as a new effective serving mode in multimedia domain. It can provide a flexible stack of powerful Virtual Machine (VM) resources of cloud like CPU, memory, storage, network bandwidth etc. on demand to manage media services and applications (e.g. image/video retrieval, video transcoding, streaming, video rendering, sharing and delivery) at lower cost. However, one major issue here is how to efficiently allocate VM resources dynamically based on applications’ QoS demands and support energy and cost savings by optimizing the number of servers in use. In order to solve this problem, we propose a cost effective and dynamic VM allocation model based on Nash bargaining solution. With various simulations it is shown that the proposed mechanism can reduce the overall cost of running servers while at the same time guarantee QoS demand and maximize resource utilization in various dimensions of server resources.

Content distribution in VANETs

Advances in vehicular communications technology are making content distribution to vehicles more effective and increasingly more popular. This paper presents state of the art technologies and protocols for content distribution in VANETs. Major challenges are Internet access spectrum scarcity, mobility, connectivity intermittence and scalability. Aspects covered in this paper include: coexistence of WiFi and LTE; application of network coding; protection from pollution attacks; incentive design for cooperation enforcement; QoS support for video streaming applications. Simulation and testbed results are presented to support the findings. Critical issues that will determine future directions in this area are identified and discussed.

Network resource management in support of QoS in ubiquitous learning

Ubiquitous learning involves a large-scale service network organized as a social infrastructure. These environments weave together context service dissemination, learner profiling as well as autonomic control of the induced network traffic. The objective of the research presented in this paper is to derive a Quality of Service aware model of ubiquitous learning services based on typical learning schemes. These pedagogical patterns are designed to match various learning situations in terms of learning context, learner profile and network infrastructure. They particularly represent classes of services in ubiquitous learning environments to prioritize traffic so that less important traffic does not consume network bandwidth and slow down or halt the delivery of more important traffic. We analyze formally and empirically the network traffic requirements of a proposed learning service quality controller to support providers of learning services allocating resources in a pervasive learning environment.

Performance Analysis and Evaluation of Hybrid Network using different Integrated Routing Protocols

The increasing demand of computer communication networks are growing rapidly day by day. With the growing need to distribute applications across multiple networks and the availability of high capacity, high-performance intermediate switching nodes, and networks, an efficient routing mechanism has become the core requirement. This research primarily focuses on the design and performance of Hybrid Network incorporating different intra-domain routing algorithms. The performance evaluation of different routing algorithms for the transmission of video- and voice-data streams over Hybrid network is demonstrated in this work.. This allows multiple Ethernet point-to-point links to be bundled into one logical full-duplex channel for Fast Ethernet (10BaseT, 100BaseT, or 1000BaseX). These applications require some QoS support such as guaranteed bandwidth, less delay, less jittering effect and low error rate. The QoS relies on a number of factors along with a suite of robust routing protocols that help to accomplish the task of moving datagram from source to destination with high bandwidth and low delay rate. An effective intra-domain network routing protocol may make distributed applications more efficient across multiple networks with the availability of high capacity and high-performance. A variety of intra-domain routing protocols such as Routing Information Protocol (RIP) and Open Shortest First Protocol (OSPF), Interior Gateway Protocol (IGRP) and Enhanced Interior Gateway Protocol (EIGRP) are available and widely used in designing such high capacity and high performance networks with optimum QoS. We evaluate the performance of these intra-domain routing protocols with IS-IS to recommend the optimum routing protocol to use to provide optimum QoS by means of OPNET Simulator TM. In this thesis work, the following objectives are considered and demonstrated.

Regressive Admission Control Enabled by Real-Time QOS Measurements

We propose a novel regressive principle to Admission Control (AC) assisted by real-time passive QoS monitoring. This measurement-based AC scheme accepts flows by default, but based on the changes in the network QoS, it makes regressive decisions on the possible flow rejection, thus bringing cognition to the network path. The REgressive Admission Control (REAC) system consists of three modules performing the necessary tasks: QoS measurements, traffic identification, and the actual AC decision making and flow control. There are two major advantages with this new scheme; (i) significant optimization of the connection start-up phase, and (ii) continuous QoS knowledge of the accepted streams. In fact, the latter combined with the REAC decisions can enable guaranteed QoS without requiring any QoS support from the network. REAC was tested on a video streaming test bed and proved to have a timely and realistic match between the network's QoS and the video quality.

A Cross-Layer Channel Access and Routing Protocol for Medical-Grade QoS Support in Wireless Sensor Networks

One of principal design issues of a Wireless Sensor Network (WSN) for medical information systems is to classify received packets based on their priorities and guarantees so that they can be transmitted reliably, thus satisfying QoS requirements. In addition, when the target WSN requires multi-hop communications and the traffic load increases significantly, it is challenging to support both load balancing and suitable QoS at the same time. In this paper, we propose a new reliable protocol termed Cross-layer Channel Access and Routing (CCAR), which simultaneously supports both MAC and routing operations for medical-grade QoS provisions. CCAR initially determines the routing path with the lowest traffic load and low latency using newly defined channel quality factors. Concurrently, the source node allocates the predefined QoS Access Category to each packet and reserves the channel along the route. In addition, CCAR introduces an effective route maintenance scheme to avoid link failures in bottlenecked intermediate nodes, which prevents unnecessary packet drops and route rediscovery evocations. Finally, through both simulation studies and real test-bed experiments, we evaluate the performance of CCAR by comparing it with other conventional protocols, demonstrating that the proposed protocol can more efficiently support medical-grade QoS packets, especially when the network is heavily loaded.

A Dynamic Bandwidth Allocation Algorithm with QoS Support in Multilink Access Network

Aiming at the problem of high packets delay and low bandwidth utilization ratio of bandwidth allocation algorithm with QoS in multilink access network environment, the structure of bandwidth allocation with QoS support is analyzed, an algorithm that using residual bandwidth reallocation dynamically for different QoS request is designed. We compared our proposed algorithm to other existing DBAQoS algorithms through extensive simulations, the simulation experiments show that the algorithm can reduce the data transmission delay and improve the bandwidth utilization ratio effectively.

Joint bandwidth allocation on dedicated and shared wavelengths for QoS support in multi‐wavelength optical access network

Wavelength-division multiplexing (WDM) technology has been recognised as one of the most promising solutions in optical access network. A general ring-based multi-wavelength optical access network based on WDM technology, which can realise triple-play service including point-to-point service and multicast service is introduced in this study. To effectively utilise the network bandwidth resources, the authors propose a joint bandwidth allocation scheme on dedicated and shared wavelengths. The proposed scheme focuses on quality of services (QoSs) support. It is carried out according to the priority queue discipline to support QoS in terms of average packet delay, packet delay variance and throughput. Moreover, with the fair-awareness in the scheduling scheme, the lower priority services can be prevented from starvation and the over-allocation problem can be avoided. The simulation results show that the proposed scheme can reduce average packet delay and packet delay variance for high-priority services to ensure QoS.

Scalability Dynamic Multicast Labels Management Mechanism for Ubiquitous Data-Centric Sensor Networks

The significant difference between traditional electric power system and smart grid is the cooperative control of power flows and information flows. With a large number of secondary equipments accessed into smart grid, the electric power communication network becomes one type of ubiquitous data-centric sensor networks. Real-time and reliable multicast services are required for power system's stable operation. Multiple Protocols Label Switching (MPLS) with its traffic engineering capabilities has emerged as a powerful tool to provide QoS support in backbone transmission networks. But previous MPLS unicast and multicast protocols have common disadvantages, not scalable enough, especially for various intelligent electronic devices following distributed generators frequently accessed into smart grid. To overcome the problems of overfull labels consuming bandwidth and prolonging delay, this paper proposed a novel labels dispatching mechanism based on Resource ReSerVation Protocol (RSVP) and message injecting and headward impelling technologies. Based on a set of accurate mathematical analyses and simulation experiments in a typical distributed power system scenario, the new mechanism could effectively reduce the total number of labels and overheads, save bandwidth, and shorten the multicast tree establishing time. The good scalability can adapt much better to ubiquitous and thick electrical advanced metering application.

Performance Enhancement of Limited-Bandwidth Industrial Control Systems

Due to its portability, reliability, flexibility, real time and rich set of QoS support, Data Distribution Service (DDs) middleware became one of the best solutions for real time distributed manufacturing systems. Most of these systems are composed of heterogeneous networked devices where network bandwidth represents a very important resource. Those devices include limited-resources devices, such as sensors, actuators and controllers. Thus, controlling such resource will significantly enhance the overall performance of the network in terms of resource utilization, delay, and throughput; moreover, it reduces the cost of using leased network bandwidth by limiting the amount of bandwidth as much as needed. In this paper we propose a solution for controlling the limited-bandwidth networked manufacturing systems by using DDS; and we describe the DDS QoS polices that support manufacturing systems to control network bandwidth. Furthermore, we evaluate DDS middleware performance over Bluetooth channel by measuring latency, throughput and jitter; and examining different QoS parameters to show their effect on improving the existing limited-bandwidth networks.

QoS-aware management of monotonic service orchestrations

We study QoS-aware management of service orchestrations, specifically for orchestrations having a data-dependent workflow. Our study supports multi-dimensional QoS. To capture uncertainty in performance and QoS, we provide support for probabilistic QoS. Under the above assumptions, orchestrations may be non-monotonic with respect to QoS, meaning that strictly improving the QoS of a service may strictly decrease the end-to-end QoS of the orchestration, an embarrassing feature for QoS-aware management. We study monotonicity and provide sufficient conditions for it. We then propose a comprehensive theory and methodology for monotonic orchestrations. Generic QoS composition rules are developed via a QoS Calculus, also capturing best service binding--service discovery, however, is not within the scope of this work. Monotonicity provides the rationale for a contract-based approach to QoS-aware management. Although function and QoS cannot be separated in the design of complex orchestrations, we show that our framework supports separation of concerns by allowing the development of function and QoS separately and then weaving them together to derive the QoS-enhanced orchestration. Our approach is implemented on top of the Orc script language for specifying service orchestrations.

Manufacturing Systems Integration Using Real Time QoS-Aware Middleware

In recent years, there has been a growth in the amount of data used to improve the production processes. As a result, the cross communication and interaction between components has increased and became a key property of modern production system. To reduce the cost of communication and to increase the efficiency of these systems, middleware technology such as CORBA, COM+, Java RMI, and Web services are being used. Middleware is becoming more and more the essential factor in improving current Manufacturing Process Automation and Control Systems, and their applications have witnessed an increased demand in real time Manufacturing Distributed Applications. In this paper, we propose publish-subscribe middleware architecture based on the Data Distribution System (DDS) open standard. The proposed architecture aims to seamlessly integrate the existing heterogeneous manufacturing systems, such as SCADA system, DCS, PLCs, and databases; and improve the communication and real time data delivery among system components; also, it provides a QoS support layer between the communicating components. Furthermore, the proposed architecture is implemented and evaluated by intensive experiments.

Performance Evaluation of IEEE 1609 WAVE for Vehicular Communications

In IEEE 1609, it uses IEEE 802.11 Enhanced Distributed Channel Access (EDCA) mechanism to access the channel. IEEE 802.11 EDCA is a new wireless technology for wireless access in the vehicular environment (WAVE). It defines a new supplement to the existing IEEE 802.11 MAC protocol. In IEEE 802.11 EDCA, the aim is providing a QoS support. While the system serves different access categories (ACs), EDCA does not perform well under high load conditions. In order to improve the efficiency, we pay attention to the EDCA with transmit opportunity (TXOP) mechanism. We first proposed a Markov chain model and studied the behavior. We extend the model to support IEEE 802.11 EDCA and presented a more accurate analysis under nonideal channel environment. We also compared it with that without TXOP mechanism under channel error environment.

Resource Allocation for QoS Support in Wireless Mesh Networks

Many next generation applications (such as video flows) are likely to have associated minimum data rate requirements in order to ensure satisfactory quality as perceived by end-users. In this paper, we develop a framework to address the problem of maximizing the aggregate utility of traffic flows in a multi-hop wireless network, with constraints imposed both due to self-interference and minimum rate requirements. The parameters that are tuned in order to maximize the utility are (i) transmission powers of individual nodes and (ii) the channels assigned to the different communication links. Our framework is based on using a cross-decomposition technique that takes both inter-flow interference and self-interference into account. The output of our framework is a schedule that dictates what links are to be activated in each slot and the parameters associated with each of those links. If the minimum rate constraint cannot be satisfied for all of the flows, the framework intelligently rejects a sub-set of the flows and recomputes a schedule for the remaining flows. We also design an admission control module that determines if new flows can be admitted without violating the rate requirements of the existing flows in the network. We provide numerical results to demonstrate the efficacy of our framework.