28,457 research outputs found

    Improving Adaptive Quality of Service for Multimedia Wireless Networks Using Hierarchical Networks Approach

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    Multimedia traffic is expected to populate the next generation wireless networks. As in wireline networks, the wireless network must able to provide a guaranteed quality of service (QoS) over the lifetime of mobile connections. Some challenging problems such as user mobility, limited frequency spectrum and shortage of bandwidth, influence the QoS provisioning for the users. This thesis examines into the issue of delivering a guaranteed quality of service (QoS) for multimedia services in wireless environment. A PhD candidate, Prihandoko have proposed an Adaptive QoS (AdQoS) model to guarantee the delivery of multimedia services. That work have been adopted and extended by means of a hierarchical network approach, calling it as Improved AdQoS model.The main objective that the Improved AdQoS framework tries to accomplish is to reduce the New Call Blocking Probability (NCBP) and Handoff Call Dropping Probability (HCDP). The key feature of this framework is the integration of the hierarchical network together with the modified Call Admission Control (CAC) algorithm and the bandwidth reallocation scheme. These schemes are developed to control the bandwidth operation of ongoing connections when the system is overloaded depending on the movement speed of a particular user assuming the speed of a mobile user would not be changed throughout the duration of a connection. The performance of the system is evaluated through simulations of a cellular environment under three different scenarios. Scenario A represents an area with 80% slow speed users and 20% fast speed users, Scenario B represents an area with a population of 40% slow speed users and 60% fast speed users while Scenario C represents an area with 20% slow speed users and 80% fast speed users. When compared with the scheme proposed Prihandoko in the literature, the simulation results show that our proposed scheme reduces the new call blocking probabilities, the handoff dropping probabilities and reduces significantly the probability of terminating call

    Joint multicast/unicast scheduling with dynamic optimization for LTE multicast service

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    This proceeding at: European Wireless 2014, took place 2014 Mai, 14-16, in Barcelona (España). The event web site of http://www.ew2014.org/Mobile video service is one of the most increasing uses expected in future generation cellular networks, including multicast video services. Based upon Evolved Multimedia Broadcast and Multicast Service (eMBMS) available with 3rd Generation Partnership Project (3GPP) release 9, Long Term Evolution (LTE) can provide broadcast/multicast content delivery with a single-frequency network mode. This means sending the same multimedia content to a mass audience within a specific area. However, it is not always possible to use multicast transmission to every user because of their different channel conditions, so unicast transmission should also be used to fulfill Quality of Service (QoS) requirements for multicast services. This paper proposes a Joint Multicast/Unicast Scheduling (JMUS) strategy for multicast service delivery. This method is based on dynamic optimization at each LTE frame, obtaining the optimal Modulation and Coding Scheme (MCS) for multicast transmission, the optimal number of subframes reserved for multicast transmission and allocating the remaining resources using a unicast scheduling metric for guaranteed data-rate. The goal of the scheduling technique proposed is to maximize the overall throughput, guaranteeing a target bit rate for all the users in the area. A new JMUS with dynamic optimization is presented to improve QoS performance. Finally, a fast search algorithm is evaluated to approach the optimal values for dynamic optimization with an order of magnitude fewer iterations than using exhaustive search.This work was supported in part by the Spanish Min-istry of Economy and Competitiveness, National Plan for Scienti?c Research, Development and Technological Inno-vation (INNPACTO subprogram), LTExtreme project (IPT- 2012-0525-430000) and the subproject TEC2011-29006-C03-03 (GRE3N-SYST).Publicad

    A Profitable and Energy-Efficient Cooperative Fog Solution for IoT Services

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    Fog-to-Fog (F2F) communication has been introduced to deliver services to clients with minimal reliance on the cloud through resource and capability sharing of cooperative fogs. Current solutions assume full cooperation among the fogs to deliver simple and composite services. Realistically, each fog might belong to a different network operator or service provider and thus will not participate in any form of collaboration unless self-monetary profit is incurred. In this paper, we introduce a fog collaboration approach for simple and complex multimedia service delivery to cloud subscribers while achieving shared profit gains for the cooperating fogs. The proposed work dynamically creates short-term service-level-agreements (SLA) offered to cloud subscribers for service delivery while maximizing user satisfaction and fog profit gains. The solution provides a learning mechanism that relies on online and offline simulation results to build guaranteed workflows for new service requests. The configuration parameters of the short-term SLAs are obtained using a modified tabu-based search mechanism that uses previous solutions when selecting new optimal choices. Performance evaluation results demonstrate significant gains in terms of service delivery success rate, service quality, reduced power consumption for fog and cloud datacenters, and increased fog profits

    Rate Adaptation for Avoiding Congestion in the Use of Multimedia Over User Datagram Protocol

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    Multimedia applications have increased rapidly in the Internet today. However, multimedia communication suffers from bandwidth requirements problem. Therefore, it is important to optimize the network bandwidth utilization. Optimizing the network bandwidth utilization allows increasing the number of users who use multimedia applications that require guaranteed quality of service. The user experiences the performance during using the network service, which is the important factor to determine the users’ satisfaction. With the limitation of the network bandwidth, multimedia traffic can cause congestion which degrades the performance experienced by the network users. Therefore, there is an essential need to reduce the occurrence of congestion situations in a network to optimize the utilization of network resources to provide the network users with suitable performance. For most of multimedia applications, UDP is used as transport protocol. Current UDP implementation helps in increasing the traffic as it does not have flow or congestion control mechanisms. Congestion can be avoided when the traffic arrival rate to a gateway maintained close to the outgoing link capacities and the gateways' queue lengths kept small to guarantee the availability of buffer capacity for successful buffering and consequent forwarding of temporary traffic upsurges which could otherwise cause buffer overflows and packet loss. Congestion management is the combined responsibility of network gateways and end-point hosts. Gateways are invested with the ability to delay or drop the packets inside the network. Gateways are responsible for congestion detection & notification delivery, queue's traffic arrival rate control, and queue length control. Traffic sources are responsible for the adjustment of their data transmission rates to enable the gateways to achieve their goals. Building a new responsive multimedia application and protocol, based on the UDP concept, can decrease the congestion occurrence and enhance the performance of the network, especially in the real-time environment

    Federated and autonomic management of multimedia services

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    Over the years, the Internet has significantly evolved in size and complexity. Additionally, the modern multimedia services it offers have considerably more stringent Quality of Service (QoS) requirements than traditional static services. These factors contribute to the ever-increasing complexity and cost to manage the Internet and its services. In the dissertation, a novel network management architecture is proposed to overcome these problems. It supports QoS-guarantees of multimedia services across the Internet, by setting up end-to-end network federations. A network federation is defined as a persistent cross-organizational agreement that enables the cooperating networks to share capabilities. Additionally, the architecture incorporates aspects from autonomic network management to tackle the ever-growing management complexity of modern communications networks. Specifically, a hierarchical approach is presented, which guarantees scalable collaboration of huge amounts of self-governing autonomic management components

    An SLA-driven framework for dynamic multimedia content delivery federations

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    Recently, the Internet has become a popular platform for the delivery of multimedia content. However, its best effort delivery approach is ill-suited to guarantee the stringent Quality of Service (QoS) requirements of many existing multimedia services, which results in a significant reduction of the Quality of Experience. This paper presents a solution to these problems, in the form of a framework for dynamically setting up federations between the stakeholders involved in the content delivery chain. More specifically, the framework provides an automated mechanism to set up end-to-end delivery paths from the content provider to the access Internet Service Providers (ISPs), which act as its direct customers and represent a group of end-users. Driven by Service Level Agreements (SLAs), QoS contracts are automatically negotiated between the content provider, the access ISPs, and the intermediary network domains along the delivery paths. These contracts capture the delivered QoS and resource reservation costs, which are subsequently used in the price negotiations between content provider and access ISPs. Additionally, it supports the inclusion of cloud providers within the federations, supporting on-the-fly allocation of computational and storage resources. This allows the automatic deployment and configuration of proxy caches along the delivery paths, which potentially reduce delivery costs and increase delivered quality

    End-to-end resource management for federated delivery of multimedia services

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    Recently, the Internet has become a popular platform for the delivery of multimedia content. Currently, multimedia services are either offered by Over-the-top (OTT) providers or by access ISPs over a managed IP network. As OTT providers offer their content across the best-effort Internet, they cannot offer any Quality of Service (QoS) guarantees to their users. On the other hand, users of managed multimedia services are limited to the relatively small selection of content offered by their own ISP. This article presents a framework that combines the advantages of both existing approaches, by dynamically setting up federations between the stakeholders involved in the content delivery process. Specifically, the framework provides an automated mechanism to set up end-to-end federations for QoS-aware delivery of multimedia content across the Internet. QoS contracts are automatically negotiated between the content provider, its customers, and the intermediary network domains. Additionally, a federated resource reservation algorithm is presented, which allows the framework to identify the optimal set of stakeholders and resources to include within a federation. Its goal is to minimize delivery costs for the content provider, while satisfying customer QoS requirements. Moreover, the presented framework allows intermediary storage sites to be included in these federations, supporting on-the-fly deployment of content caches along the delivery paths. The algorithm was thoroughly evaluated in order to validate our approach and assess the merits of including intermediary storage sites. The results clearly show the benefits of our method, with delivery cost reductions of up to 80 % in the evaluated scenario

    Design of a middleware for QoS-aware distribution transparent content delivery

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    Developers of distributed multimedia applications face a diversity of multimedia formats, streaming platforms and streaming protocols. Furthermore, support for end-to-end quality-of-service (QoS) is a crucial factor for the development of future distributed multimedia systems. This paper discusses the architecture, design and implementation of a QoS-aware middleware platform for content delivery. The platform supports the development of distributed multimedia applications and can deliver content with QoS guarantees. QoS support is offered by means of an agent infrastructure for QoS negotiation and enforcement. Properties of content are represented using a generic content representation model described using the OMG Meta Object Facility (MOF) model. A content delivery framework manages stream paths for content delivery despite differences in streaming protocols and content encoding. The integration of the QoS support, content representation and content delivery framework results in a QoS-aware middleware that enables representation transparent and location transparent delivery of content

    Quality of service assurance for the next generation Internet

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    The provisioning for multimedia applications has been of increasing interest among researchers and Internet Service Providers. Through the migration from resource-based to service-driven networks, it has become evident that the Internet model should be enhanced to provide support for a variety of differentiated services that match applications and customer requirements, and not stay limited under the flat best-effort service that is currently provided. In this paper, we describe and critically appraise the major achievements of the efforts to introduce Quality of Service (QoS) assurance and provisioning within the Internet model. We then propose a research path for the creation of a network services management architecture, through which we can move towards a QoS-enabled network environment, offering support for a variety of different services, based on traffic characteristics and user expectations
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