461 research outputs found
Dynamic Bandwidth Allocation in ATM Networks
Today's new applications such as World Wide Web, video conferencing and
multimedia have introduced a large amount of traffic into the network. Additionally
new applications are also heading towards real time process. Instant access to the
network, greater level of performances and higher degree of satisfaction has
become the main concerns of users using these new applications. Although current
transmission mediums have advanced in capacity through means such as optical
fiber and Gigabit Ethernet, future and unknown new services tend to consume up
the available bandwidth. ATM network is the new technology used to support a
wide variety of services including data, voice, video and most possibly other future
applications. Its flexibility, efficiency and high throughput have gained popularity
but with greater complexity due to different approaches in handling different type
of services.A high-speed network such as ATM networks must have an effective traffic
management scheme in order to gain high data throughput with the least cost of
operation. Thus, simulation and modeling are the effective methods used to design
the trade-off between network parameters and their performances. Effective sharing
of network resources such as bandwidth and buffer are studied through the dynamic
allocation method. Static allocation scheme has been proven inefficient to provide
high resources utilization as can be seen in STM networks compared to A TM
networks. However, ATM networks should provide different dynamic allocation
methods according to its different services and traffic characteristics. Four dynamic
allocation strategies have been designed, evaluated and compared for their
performances. They are called Static Bandwidth Allocation, Bandwidth Allocated
Proportional to Expected Queue Length, Bandwidth Allocated Proportional to
Expected Queue Length with Threshold Value and Bandwidth Allocated with
Threshold Interrupt. Bandwidth Allocated with Threshold Interrupt is proven to be
the most effective strategy as it could response to congestion immediately
Quality of Service over Specific Link Layers: state of the art report
The Integrated Services concept is proposed as an enhancement to the current Internet architecture, to provide a better Quality of Service (QoS) than that provided by the traditional Best-Effort service. The features of the Integrated Services are explained in this report. To support Integrated Services, certain requirements are posed on the underlying link layer. These requirements are studied by the Integrated Services over Specific Link Layers (ISSLL) IETF working group. The status of this ongoing research is reported in this document. To be more specific, the solutions to provide Integrated Services over ATM, IEEE 802 LAN technologies and low-bitrate links are evaluated in detail. The ISSLL working group has not yet studied the requirements, that are posed on the underlying link layer, when this link layer is wireless. Therefore, this state of the art report is extended with an identification of the requirements that are posed on the underlying wireless link, to provide differentiated Quality of Service
Dynamic bandwidth allocation in ATM networks
Includes bibliographical references.This thesis investigates bandwidth allocation methodologies to transport new emerging bursty traffic types in ATM networks. However, existing ATM traffic management solutions are not readily able to handle the inevitable problem of congestion as result of the bursty traffic from the new emerging services. This research basically addresses bandwidth allocation issues for bursty traffic by proposing and exploring the concept of dynamic bandwidth allocation and comparing it to the traditional static bandwidth allocation schemes
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Future of asynchronous transfer mode networking
The growth of Asynchronous Transfer Mode (ATM) was considered to be the ideal carrier of the high bandwidth applications like video on demand and multimedia e-learning. ATM emerged commercially in the beginning of the 1990\u27s. It was designed to provide a different quality of service at a speed up 100 Gbps for both real time and non real time application. The turn of the 90\u27s saw a variety of technologies being developed. This project analyzes these technologies, compares them to the Asynchronous Transfer Mode and assesses the future of ATM
Supporting real time video over ATM networks
Includes bibliographical references.In this project, we propose and evaluate an approach to delimit and tag such independent video slice at the ATM layer for early discard. This involves the use of a tag cell differentiated from the rest of the data by its PTI value and a modified tag switch to facilitate the selective discarding of affected cells within each video slice as opposed to dropping of cells at random from multiple video frames
Transmission of variable bit rate video over an Orwell ring
Asynchronous Transfer Mode (ATM) is fast emerging as the preferred information
transfer technique for future Broadband Integrated Services Digital Networks (BISON),
offering the advantages of both the simplicity of time division circuit switched techniques
and the flexibility of packet switched techniques. ATM networks with their inherent rate
flexibility offer new opportunities for the efficient transmission of real time Variable Bit
Rate (VBR) services over such networks. Since most services are VBR in nature when
efficiently coded, this could in turn lead to a more efficient utilisation of network resources
through statistical multiplexing. Video communication is typical of such a service and could
benefit significantly if supported with VBR video over ATM networks. [Continues.
User-Oriented QoS in Packet Video Delivery
We focus on packet video delivery, with an emphasis on the quality of service perceived by the end-user. A video signal passes through several subsystems, such as the source coder, the network and the decoder. Each of these can impair the information, either by data loss or by introducing delay. We describe how each of the subsystems can be tuned to optimize the quality of the delivered signal, for a given available bit rate in the network. The assessment of end-user quality is not trivial. We present recent research results, which rely on a model of the human visual system
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