298 research outputs found

    A Review of MAC Scheduling Algorithms in LTE System

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    The recent wireless communication networks rely on the new technology named Long Term Evolution (LTE) to offer high data rate real-time (RT) traffic with better Quality of Service (QoS) for the increasing demand of customer requirement. LTE provide low latency for real-time services with high throughput, with the help of two-level packet retransmission. Hybrid Automatic Repeat Request (HARQ) retransmission at the Medium Access Control (MAC) layer of LTE networks achieves error-free data transmission. The performance of the LTE networks mainly depends on how effectively this HARQ adopted in the latest communication standard, Universal Mobile Telecommunication System (UMTS). The major challenge in LTE is to balance QoS and fairness among the users. Hence, it is very essential to design a down link scheduling scheme to get the expected service quality to the customers and to utilize the system resources efficiently. This paper provides a comprehensive literature review of LTE MAC layer and six types of QoS/Channel-aware downlink scheduling algorithms designed for this purpose. The contributions of this paper are to identify the gap of knowledge in the downlink scheduling procedure and to point out the future research direction. Based on the comparative study of algorithms taken for the review, this paper is concluded that the EXP Rule scheduler is most suited for LTE networks due to its characteristics of less Packet Loss Ratio (PLR), less Packet Delay (PD), high throughput, fairness and spectral efficiency

    QoS scheduling for energy-efficient wireless communication

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    Presents a QoS (quality of service) scheduler that assigns bandwidth over a wireless channel such that the amount of energy spent by a mobile device is minimized, while maintaining the QoS of the connections. Energy efficiency is an important issue for mobile computers, since they must rely on their batteries. We have designed and implemented an energy-efficient architecture and MAC protocol for wireless multimedia traffic. The scheduling is based on two mechanisms: (1) short-term transmission frame scheduling that concatenates the uplink and downlink traffic of a mobile device, and (2) long-term scheduling that tries to collect traffic as much as possible within the QoS requirements of the connections. The result is that the transceiver can be in a low-power operating mode for an extended period of time and that the number of operating mode transitions is reduce

    New cross-domain QoE guarantee method based on isomorphism flow

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    This paper investigates the issue of Quality of Experience(QoE)for multimedia services over heterogeneous networks. Anew concept of “Isomor-phism Flow”(iFlow) was introduced for analyzing multimedia traffics, which is inspired by the abstract algebrabased on experimental research. By using iF-low, the multimedia traffics with similar QoErequirements for differentusersare aggregated. AQoE evaluation method was also proposed for the aggregated traffics. Then a new cross-domain QoE guarantee method based on the iFlow QoEis proposed in this paper to adjust the network resource fromthe perspec-tive of user perception.The proposed scheme is validated through simulations. Simulationresults show that the proposed scheme achieves an enhancement in QoE performanceandoutperforms the existing schemes

    Multicast resource management for next generation mobile communication systems

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    EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Project Final Report – FREEDOM ICT-248891

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    This document is the final publishable summary report of the objective and work carried out within the European Project FREEDOM, ICT-248891.This document is the final publishable summary report of the objective and work carried out within the European Project FREEDOM, ICT-248891.Preprin

    Service oriented networking for multimedia applications in broadband wireless networks

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    Extensive efforts have been focused on deploying broadband wireless networks. Providing mobile users with high speed network connectivity will let them run various multimedia applications on their wireless devices. In order to successfully deploy and operate broadband wireless networks, it is crucial to design efficient methods for supporting various services and applications in broadband wireless networks. Moreover, the existing access-oriented networking solutions are not able to fully address all the issues of supporting various applications with different quality of service requirements. Thus, service-oriented networking has been recently proposed and has gained much attention. This dissertation discusses the challenges and possible solutions for supporting multimedia applications in broadband wireless networks. The service requirements of different multimedia applications such as video streaming and Voice over IP (VoIP) are studied and some novel service-oriented networking solutions for supporting these applications in broadband wireless networks are proposed. The performance of these solutions is examined in WiMAX networks which are the promising technology for broadband wireless access in the near future. WiMAX networks are based on the IEEE 802.16 standards which have defined different Quality of Service (QoS) classes to support a broad range of applications with varying service requirements to mobile and stationary users. The growth of multimedia traffic that requires special quality of service from the network will impose new constraints on network designers who should wisely allocate the limited resources to users based on their required quality of service. An efficient resource management and network design depends upon gaining accurate information about the traffic profile of user applications. In this dissertation, the access level traffic profile of VoIP applications are studied first, and then a realistic distribution model for VoIP traffic is proposed. Based on this model, an algorithm to allocate resources for VoIP applications in WiMAX networks is investigated. Later, the challenges and possible solutions for transmitting MPEG video streams in wireless networks are discussed. The MPEG traffic model adopted by the WiMAX Forum is introduced and different application-oriented solutions for enhancing the performance of wireless networks with respect to MPEG video streaming applications are explained. An analytical framework to verify the performance of the proposed solutions is discoursed, and it is shown that the proposed solutions will improve the efficiency of VoIP applications and the quality of streaming applications over wireless networks. Finally, conclusions are drawn and future works are discussed

    Impact of network dynamics on user\u27s video quality : analytical framework and QoS provision

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