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Packet Scheduling (packet + scheduling)
Selected AbstractsQoS-aware fair packet scheduling in IEEE 802.16 wireless mesh networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 6-7 2010Yajun Li Abstract In this paper, we address the problem of heterogeneous quality-of-service (QoS) provisioning in IEEE 802.16-based wireless mesh networks. Our objective is to provide a novel service differentiation scheme based on distributed scheduling in the IEEE 802.16-based mesh mode, thereby offering QoS guarantees. We first devise a novel scheme for the traffic class differentiation, which can be implemented at the medium access control layer. We then present a QoS-aware fair packet scheduling (QFPS) algorithm to fulfill the QoS provisioning. With QFPS, a traffic flow with urgent QoS demand is guaranteed to be given priority in wireless resource allocation over those ones with mild QoS requirements. A shorter end-to-end delay is therefore expected to be offered for the traffic flows with time-urgent requirements. Moreover, we propose a new fairness model among different traffic flows traversing the same node. All traffic flows passing through a node are served by the Deficit Round-Robin scheduling algorithm to achieve fairness within the same priority group. The experimental results of the QFPS demonstrate that various traffic flows are provided with a differentiated service that offers QoS guarantees. Copyright © 2009 John Wiley & Sons, Ltd. [source] Joint packet scheduling and dynamic base station assignment for CDMA data networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 2 2008Christian Makaya Abstract In current code division multiple access (CDMA) based wireless systems, a base station (BS) schedules packets independently of its neighbours, which may lead to resource wastage and the degradation of the system's performance. In wireless networks, in order to achieve an efficient packet scheduling, there are two conflicting performance metrics that have to be optimized: throughput and fairness. Their maximization is a key goal, particularly in next-generation wireless networks. This paper proposes joint packet scheduling and BS assignment schemes for a cluster of interdependent neighbouring BSs in CDMA-based wireless networks, in order to enhance the system performance through dynamic load balancing. The proposed schemes are based on sector subdivision in terms of average required resource per mobile station and utility function approach. The fairness is achieved by minimizing the variance of the delay for the remaining head-of-queue packets. Inter-cell and intra-cell interferences from scheduled packets are also minimized in order to increase the system capacity and performance. The simulation results show that our proposed schemes perform better than existing schemes available in the open literature. Copyright © 2007 John Wiley & Sons, Ltd. [source] Core-stateless fair rate estimation fair queuingINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 6 2006Jung-Shian Li Abstract Core-stateless mechanisms, such as core-stateless fair queuing (CSFQ), reduce the complexity of fair queuing, which usually need to maintain states, manage buffers, and perform flow scheduling on a per-flow basis. However, they require executing label rewriting and dropping decision on a per-packet basis, thus preventing them from being widely deployed. In this paper, we propose a novel architecture based on CSFQ without per-packet labelling. Similarly, we distinguish between edge routers and core routers. Edge routers maintain the per-flow state by employing a fair queuing mechanism to allocate each flow a fair bandwidth share locally and a token bucket mechanism to regulate those flows with feedback packets sent from egress edge routers. Core routers do not maintain per-flow state; they use FIFO packet scheduling extended by a fare rate alarm mechanism by estimating the arrival rate and the number of flows using a matching,mismatching algorithm. The novel scheme is called core-stateless fair rate estimation fair queuing (CSFREFQ). CSFREFQ is proven to be capable of achieving max,min fairness. Furthermore, we present and discuss simulations and experiments on the performance under different traffic scenarios. Copyright © 2005 John Wiley & Sons, Ltd. [source] Managing QoS requirements for video streaming: from intra-node to inter-nodeINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 5 2006Y. Bai Abstract Streaming video over IP networks has become increasingly popular; however, compared to traditional data traffic, video streaming places different demands on quality of service (QoS) in a network, particularly in terms of delay, delay variation, and data loss. In response to the QoS demands of video applications, network techniques have been proposed to provide QoS within a network. Unfortunately, while efficient from a network perspective, most existing solutions have not provided end-to-end QoS that is satisfactory to users. In this paper, packet scheduling and end-to-end QoS distribution schemes are proposed to address this issue. The design and implementation of the two schemes are based on the active networking paradigm. In active networks, routers can perform user-driven computation when forwarding packets, rather than just simple storing and forwarding packets, as in traditional networks. Both schemes thus take advantage of the capability of active networks enabling routers to adapt to the content of transmitted data and the QoS requirements of video users. In other words, packet scheduling at routers considers the correlation between video characteristics, available local resources and the resulting visual quality. The proposed QoS distribution scheme performs inter-node adaptation, dynamically adjusting local loss constraints in response to network conditions in order to satisfy the end-to-end loss requirements. An active network-based simulation shows that using QoS distribution and packet scheduling together increases the probability of meeting end-to-end QoS requirements of networked video. Copyright © 2005 John Wiley & Sons, Ltd. [source] Efficient packet scheduling for heterogeneous multimedia provisioning over broadband satellite networks: An adaptive multidimensional QoS-based designINTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 1 2009Hongfei Du Abstract With their inherent broadcast capabilities and reliable extensive geographical coverage, the broadband satellite networks are emerging as a promising approach for the delivery of multimedia services in 3G and beyond systems. Given the limited capacity of the satellite component, to meet the diverse quality of service (QoS) demands of multimedia applications, it is highly desired that the available resources can be adaptively utilized in an optimized way. In this paper, we draw our attention on the development and evaluation of an efficient packet scheduling scheme in a representative broadband satellite system, namely satellite digital multimedia broadcasting (SDMB), which is positioned as one of the most attractive solutions in the convergence of a closer integration with the terrestrial mobile networks for a cost-effective delivery of point-to-multipoint services. By taking into account essential aspects of a successful QoS provisioning while preserving the system power/resource constraints, the proposed adaptive multidimensional QoS-based (AMQ) packet scheduling scheme in this paper aims to effectively satisfy diverse QoS requirements and adaptively optimize the resource utilization for the satellite multimedia broadcasting. The proposed scheme is formulated via an adaptive service prioritization algorithm and an adaptive resource allocation algorithm. By taking into account essential performance criteria, the former is capable of prioritizing contending flows based on the QoS preferences and performance dynamics, while the latter allocates the resources, in an adaptive manner, according to the current QoS satisfaction degree of each session. Simulation results show that the AMQ scheme achieves significantly better performance than those of existing schemes on multiple performance metrics, e.g. delay, throughput, channel utilization and fairness. Copyright © 2008 John Wiley & Sons, Ltd. [source] Radio resource management across multiple protocol layers in satellite networks: a tutorial overviewINTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 5 2005Paolo Barsocchi Abstract Satellite transmissions have an important role in telephone communications, television broadcasting, computer communications, maritime navigation, and military command and control. Moreover, in many situations they may be the only possible communication set-up. Trends in telecommunications indicate that four major growth market/service areas are messaging and navigation services (wireless and satellite), mobility services (wireless and satellite), video delivery services (cable and satellite), and interactive multimedia services (fibre/cable, satellite). When using geostationary satellites (GEO), the long propagation delay may have great impact, given the end-to-end delay user's requirements of relevant applications; moreover, atmospheric conditions may seriously affect data transmission. Since satellite bandwidth is a relatively scarce resource compared to the terrestrial one (e.g. in optical transport networks), and the environment is harsher, resource management of the radio segment plays an important role in the system's efficiency and economy. The radio resource management (RMM) entity is responsible for the utilization of the air interface resources, and covers power control, handover, admission control, congestion control, bandwidth allocation, and packet scheduling. RRM functions are crucial for the best possible utilization of the capacity. RRM functions can be implemented in different ways, thus having an impact on the overall system efficiency. This tutorial aims to provide an overview of satellite transmission aspects at various OSI layers, with emphasis on the MAC layer; some cross-layer solutions for bandwidth allocation are also indicated. Far from being an exhaustive survey (mainly due to the extensive nature of the subject), it offers the readers an extensive bibliography, which could be used for further research on specific aspects. Copyright © 2005 John Wiley & Sons, Ltd. [source] | ||||||||||