Bandwidth Allocation (bandwidth + allocation)

Distribution by Scientific Domains

Selected Abstracts

Neural bandwidth allocation function (NBAF) control scheme at WiMAX MAC layer interface

Mario Marchese
Abstract The paper proposes a bandwidth allocation scheme to be applied at the interface between upper layers (IP, in this paper) and Medium Access Control (MAC) layer over IEEE 802.16 protocol stack. The aim is to optimally tune the resource allocation to match objective QoS (Quality of Service) requirements. Traffic flows characterized by different performance requirements at the IP layer are conveyed to the IEEE 802.16 MAC layer. This process leads to the need for providing the necessary bandwidth at the MAC layer so that the traffic flow can receive the requested QoS. The proposed control algorithm is based on real measures processed by a neural network and it is studied within the framework of optimal bandwidth allocation and Call Admission Control in the presence of statistically heterogeneous flows. Specific implementation details are provided to match the application of the control algorithm by using the existing features of 802.16 request,grant protocol acting at MAC layer. The performance evaluation reported in the paper shows the quick reaction of the bandwidth allocation scheme to traffic variations and the advantage provided in the number of accepted calls. Copyright 2006 John Wiley & Sons, Ltd. [source]

Dynamic bandwidth allocation and buffer dimensioning under equal segment scheme to support video-on-demand services

Liren Zhang
Abstract This paper focuses on the optimization of network bandwidth allocation and buffer dimensioning to transport pre-stored MPEG video data from source to playback destination across ATM networks. This is one of the most important issues in the support of video-on-demand (VoD) service. This paper provides a novel scheme in the dynamic allocation of bandwidth to segments of video using ABR mode. The dynamic bandwidth allocation is based on a new concept, called playback tunnel which is obtained from the traffic characteristics of the pre-stored MPEG video trace to determine the optimum of transmission bandwidth as well as the buffer capacity to ensure that the playback buffer neither underflows nor overflows. The proposed scheme is tested with real-life MPEG video traces. The obtained results have shown its significant performance improvement in terms of the capacity of playback buffer, the start-up playback delay, the size of video segment and the network multiplexing gain. Copyright 2001 John Wiley & Sons, Ltd. [source]

Performance of ATM traffic in optical CDMA

Liren Zhang
Abstract An ATM transit switch is proposed based on direct sequence optical code division multiple access technique. No buffering is necessary to facilitate the switching. Code conversion is used instead to emulate the switching function. The switch not only provides asynchronous access to the users but also has a limited capability of dynamic bandwidth allocation. It is free from timing jitters and switching delay is significantly reduced. A look-up table is employed in the switching and updated through network management functions. The switch provides a new approach to asynchronous cross-connection in the ATM core network. The performance of the new switch is evaluated by a set of prime codes and modified prime codes. Copyright 2001 John Wiley & Sons, Ltd. [source]

A game-theoretic model for capacity-constrained fair bandwidth allocation

Yonghe Yan
Data stream providers face a hard decision to satisfy the requirements of their subscribers. Each user has a minimum and a maximum required bandwidth. The server should be able to decide which requests can be satisfied and how much bandwidth will be allocated to each. We present a theoretical framework in a distributed mechanism for fair bandwidth allocation on a network with various bottleneck links. In our model, a user is guaranteed a minimum bandwidth and charged a price for the bandwidth allocated. A utility function is defined over the allocated bandwidth for a specific maximum requested bandwidth. We then present a non-cooperative game with social welfare function to resolve users' conflicting bandwidth capacity requests at bottleneck links. We also show that our proposed game-theoretic solution guarantees fair bandwidth allocation as defined in our residual capacity fairness. In order to guarantee the minimum bandwidth requirement, we integrate an admission control mechanism in our solution. However, global optimal admission conditions are not easy to implement for large networks. Therefore, we propose a distributed admission scheme. As a result, the paper presents fair and practical distributed algorithms for bandwidth allocation and admission control in enterprise networks. Our simulation and evaluation study shows that the distributed approach is sufficiently close to the global optimal solution. Copyright 2008 John Wiley & Sons, Ltd. [source]

Short-term MPEG-4 video traffic prediction using ANFIS

Adel Abdennour
Multimedia traffic and particularly MPEG-coded video streams are growing to be a major traffic component in high-speed networks. Accurate prediction of such traffic enhances the reliable operation and the quality of service of these networks through a more effective bandwidth allocation and better control strategies. However, MPEG video traffic is characterized by a periodic correlation structure, a highly complex bit rate distribution and very noisy streams. Therefore, it is considered an intractable problem. This paper presents a neuro-fuzzy short-term predictor for MPEG-4-coded videos. The predictor is based on the Adaptive Network Fuzzy Inference System (ANFIS) to perform single-step predictions for the I, P and B frames. Short-term predictions are also examined using smoothed signals of the video sequences. The ANFIS prediction results are evaluated using long entertainment and broadcast video sequences and compared to those obtained using a linear predictor. ANFIS is capable of providing accurate prediction and has the added advantage of being simple to design and to implement. Copyright 2005 John Wiley & Sons, Ltd. [source]

Radio resource management across multiple protocol layers in satellite networks: a tutorial overview

Paolo 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]

Quality of service for satellite IP networks: a survey

Sastri Kota
Abstract The future media rich applications such as media streaming, content delivery distribution and broadband access require a network infrastructure that offers greater bandwidth and service level guarantees. As the demand for new applications increases, ,best effort' service is inadequate and results in lack of user satisfaction. End-to-end quality of service (QoS) requires the functional co-operation of all network layers. To meet future application requirements, satellite is an excellent candidate due to features such as global coverage, bandwidth flexibility, broadcast, multicast and reliability. At each layer, the user performance requirements should be achieved by implementation of efficient bandwidth allocation algorithms and satellite link impairment mitigation techniques. In this paper, a QoS framework for satellite IP networks including requirements, objectives and mechanisms are described. To fully understand end-to-end QoS at each layer, QoS parameters and the current research are surveyed. For example at physical layer (modulation, adaptive coding), link layer (bandwidth allocation), network layer (IntServ/DiffServ, MPLS traffic engineering), transport layer (TCP enhancements, and alternative transport protocols) and security issues are discussed. Some planned system examples, QoS simulations and experimental results are provided. The paper also includes the current status of the standardization of satellite IP by ETSI, ITU and IETF organizations. Copyright 2003 John Wiley & Sons, Ltd. [source]