Search results for "Quality of Service"
showing 10 items of 194 documents
A New Universal-Environment Adaptive Multi-processor Scheduler for Autonomous Cyber-Physical System
2012
International audience; Robot, spaceship and other applications that can be called autonomous Cyber-Physical Systems (CPS) are all smart embedded systems, which usually run in open environment by themselves with inhered intelligent capabilities. Besides the application intelligence, the researches of adaptive platform for such systems have also become topics recently. Based on the analysis of current work, a new environment adaptive scheduler (¦Á-S) for multiprocessor platform of a cyber-physical system is proposed in this article. And then, its related structures, models, and reasoning methods are studied deeply. Different from the existing ones, ¦Á-S can schedule all tasks according to th…
Network architectures and energy efficiency for high performance data centers
2017
The increasing trend to migrate applications, computation and storage into more robust systems leads to the emergence of mega data centers hosting tens of thousands of servers. As a result, designing a data center network that interconnects this massive number of servers, and providing efficient and fault-tolerant routing service are becoming an urgent need and a challenge that will be addressed in this thesis. Since this is a hot research topic, many solutions are proposed like adapting new interconnection technologies and new algorithms for data centers. However, many of these solutions generally suffer from performance problems, or can be quite costly. In addition, devoted efforts have n…
Improving IoT Communications Based on Smart Routing Algorithms
2018
International audience; Due to the recorded success by Internet of Things (IoT) technology, more and more domains use it as a communications and exchange network such as e-health, smart cities, vehicles, etc. IoT don’t stop integrating an important number of components and objects that are characterized by their complexity and heterogeneity. Such constraints make the existing routings protocols unsuitable for IoT communications. To accomplish all the expected tasks and satisfy the user services, it is important to guarantee a quality of communication that answers to the requirements of the various applications in terms of data and processing (availability, integrity, efficiency, etc.). The …
Network Capacity Estimators Predicting QoE in HTTP Adaptive Streaming
2022
The aim of adaptive HTTP streaming technology is preserving the best possible video streaming quality for viewers in heterogeneous network conditions. This can be achieved by making multiple quality versions of the video available. Switching between versions during playback should be imperceptible and fluent. The decision about quality-level switching is typically based on network capacity estimation and buffer occupancy, which predict the risk of stalling. Since quality-level switching and stalling are directly evident to the user, they are often classified as influence factors of quality of experience (QoE). In this paper, we observe different network capacity estimators and buffer behavi…
Service level guarantee framework for IoT environments
2017
Nowadays, providing IoT environments with service level guarantee is a challenging task. We propose a framework for IoT service level guarantee thanks to several specific Service Level Agreements (SLAs) for IoT environments. We specify different SLAs for each entity contributing in our IoT architecture in order to conclude a global SLA called IoT-SLA (iSLA). These different SLAs enable IoT service provision with Quality of Service (QoS) guarantee. Achieving this guarantee requires several communications and interactions between the components of the proposed IoT architecture. These interactions allow an IoT Service Provider (IoT-SP) to conclude the iSLA with an IoT Client (IoT-C). We specif…
Channel Occupancy-Based Dynamic Spectrum Leasing in Multichannel CRNs: Strategies and Performance Evaluation
2016
Spectrum leasing has been proposed as an effective approach for enabling more flexible spectrum utilization in CRNs. In CRNs, a primary network (PN) which consists of multiple primary users (PUs) can lease part of the licensed spectrum to secondary users (SUs) in exchange for operational benefits. The focus of this study is to investigate how and to what extent the PN allows spectrum leasing in CRNs, considering the QoS requirements of the PN and the secondary network (SN). Correspondingly, we propose two dynamic spectrum leasing strategies, which can improve the QoS performance of SUs while ensuring sufficient remuneration for PUs. In order to dynamically adjust the portion of leased bandw…
Temporal Fairness Provisioning in Multi-Rate Contention-Based 802.11e WLANs
2005
The IEEE 802.11e extensions for QoS support in WLAN define the transmission opportunity (TXOP) concept, in order to limit the channel holding times of the contending stations in the presence of delay-sensitive traffic. We evaluate the use of TXOP for a different purpose: "temporal fairness" provisioning among stations employing different data rates. We show that the equalization of the channel access times allows each station to obtain its throughput basically (1) proportional to its transmission rate, and (2) independent of the transmitted frame length. This also improves the aggregate throughput of the overall WLAN. For a given TXOP limit, i.e., a granted channel access time, a station is…
A new inter-cloud service-level guarantee protocol applied to space missions
2017
Nowadays, the term cloud computing often falsely assumes the availability of an unlimited pool of resources. On the contrary, if a cloud provider reaches its limits, it may pose the risk of breaking their service level agreement (SLA). Space agencies could start using the cloud computing model within their IT infrastructure with multiple ground control points around the world to reduce the cost. An inter-cloud communication protocol with a guarantee of the service level will significantly reduce the cost if each ground control segment is considered as a cloud provider. This paper outlines a new protocol that was developed to take into consideration the end-to-end service-level guarantee. Th…
Blockchain based Inter-domain Latency Aware Routing Proposal in Software Defined Network
2018
Border gateway protocol (BGP) version 4 is routing current Internet for more than 20 years. BGP is the only protocol that has proven its routing capability of such size network with continually growing nature. Although BGP is scalable and network layer reachability information it lacks quality of service metrics like latency. BGP routing decision algorithm uses as-path length between autonomous systems (AS) as main factor for most of its best-path calculations. Because of more affordable peering architectures as-path length is generally decreasing in worldwide internet network resulting in less efficient routes for real-time internet protocol traffic. This study proposes future internet arc…
Performance evaluation of a measurement-based algorithm for distributed admission control in a DiffServ framework
2002
Distributed Admission Control in IP DiffServ environments is an emerging and promising research area. Distributed admission control solutions share the idea that no coordination among network routers (i.e. explicit signaling) is necessary, when the decision whether to admit or reject a new offered flow is pushed to the edge of the IP network. Proposed solutions differ in the degree of complexity required in internal network routers, and result in a different robustness and effectiveness in controlling the accepted traffic. This paper builds on a recently proposed distributed admission control solution, called GRIP (Gauge&Gate Reservation with Independent Probing), designed to integrate the …