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Network management issues for the optical access networkMistry, Bharat January 1996 (has links)
No description available.
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Motion compensation for 2D object-based video codingSteliaros, Michael Konstantinos January 1999 (has links)
No description available.
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Superresolution techniques for passive millimetre wave imagesRollason, Malcolm January 1999 (has links)
No description available.
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Joint bandwidth and power allocation in wireless communication networksGong, Xiaowen 11 1900 (has links)
This thesis consists of two studies on joint bandwidth and power allocation strategy for wireless communication
networks. In the first study, joint bandwidth and power allocation strategy is proposed for wireless multi-user networks without relaying and with decode-and-forward relaying. It is shown that the formulated resource allocation problems are convex and, thus, can be solved efficiently. Admission control problem based on the joint bandwidth and power allocation strategy is further considered, and a greedy search algorithm is developed for solving it efficiently. In the second study, joint bandwidth
and power allocation strategy is presented for maximizing the sum ergodic capacity of secondary users under fading channels in cognitive radio networks. Optimal bandwidth allocation is derived in closed-form for any given power allocation. Then the structures of optimal power allocations are derived. Using these structures, efficient algorithms are developed for finding the optimal power allocations. / Communications
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QoS evaluation of bandwidth schedulersin IPTV networks offered SRD fluidvideo traffic: a simulation studyIslam, Md Rashedul January 2009 (has links)
IPTV is now offered by several operators in Europe, US and Asia using broadcast video over private IP networks that are isolated from Internet. IPTV services rely ontransmission of live (real-time) video and/or stored video. Video on Demand (VoD)and Time-shifted TV are implemented by IP unicast and Broadcast TV (BTV) and Near video on demand are implemented by IP multicast. IPTV services require QoS guarantees and can tolerate no more than 10-6 packet loss probability, 200 ms delay, and 50 ms jitter. Low delay is essential for satisfactory trick mode performance(pause, resume,fast forward) for VoD, and fast channel change time for BTV. Internet Traffic Engineering (TE) is defined in RFC 3272 and involves both capacity management and traffic management. Capacity management includes capacityplanning, routing control, and resource management. Traffic management includes (1)nodal traffic control functions such as traffic conditioning, queue management, scheduling, and (2) other functions that regulate traffic flow through the network orthat arbitrate access to network resources. An IPTV network architecture includes multiple networks (core network, metronetwork, access network and home network) that connects devices (super head-end, video hub office, video serving office, home gateway, set-top box). Each IP router in the core and metro networks implements some queueing and packet scheduling mechanism at the output link controller. Popular schedulers in IP networks include Priority Queueing (PQ), Class-Based Weighted Fair Queueing (CBWFQ), and Low Latency Queueing (LLQ) which combines PQ and CBWFQ.The thesis analyzes several Packet Scheduling algorithms that can optimize the tradeoff between system capacity and end user performance for the traffic classes. Before in the simulator FIFO,PQ,GPS queueing methods were implemented inside. This thesis aims to implement the LLQ scheduler inside the simulator and to evaluate the performance of these packet schedulers. The simulator is provided by ErnstNordström and Simulator was built in Visual C++ 2008 environmentand tested and analyzed in MatLab 7.0 under windows VISTA.
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Design of Compact Antennas in Multilayer Technology for Wireless Communications / WLAN ApplicationsDeJean, Gerald Reuben 04 February 2005 (has links)
Various compact and packaging-adaptive antennas have been designed for practical wireless communications systems such as global system of mobile communications (GSM), Bluetooth Industrial-Scientific-Medical (ISM) devices, IEEE802.11a WLAN, and Local Multipoint Distribution Systems (LMDS) applications. First, compact stacked patch antennas using LTCC multilayer technology have been presented. A set of design rules is established for the purpose of designing optimized bandwidth compact antennas on LTCC multilayer substrates. To verify its effectiveness, the proposed design rules are applied to three emerging wireless bands. The return loss and the impedance bandwidth are optimized for all three bands. A maximum bandwidth of 7% can be achieved for an antenna operating in the LMDS band. Furthermore,
folded shorted patch antennas (SPAs) are designed to significantly reduce the resonant frequency of a standard patch antenna. The design methodology of this structure starts with a conventional half-wave and through a series of procedures, evolves into a smaller, lambda/8 wavelength resonant length structure. Upon varying the height of the lower patch, the resonant length can be reduced to lambda/16. A comparison between a folded SPA and a standard SPA validates the folding technique proposed in this document. The folded SPA is applied to the 2.4 GHz ISM band. The measured results are in good agreement with simulated results. This antenna can be implemented into 3D packages using multilayer laminates such as LTCC or LCP.
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Design and Characterization of RFID Modules in Multilayer ConfigurationsBasat, Sabri S. 05 January 2007 (has links)
Radio Frequency IDentification (RFID) Tags have become quite widespread in many services in the industry such as access control, parcel and document tracking, distribution logistics, automotive systems, and livestock or pet tracking. In these applications, a wireless communication link is provided between a remote transponder (antenna and integrated circuit (IC)) and an interrogator or reader. A suitable antenna for these tags must have low cost, low profile and especially small size whereas the bandwidth requirement (few kilohertz to megahertz) is less critical.
In this document, methods to reduce tag size, the performance optimization of the tag by using novel antenna matching techniques for increased operational bandwidth and gain/radiation pattern/radiation efficiency improvement are introduced for 13.56 MHz HF and 915 MHz UHF RFID tags.In addition, an evaluation of an active 915 MHz UHF RFID field study for container tracking at the port of Savannah, GA is also presented.
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Integration of UMTS Bandwidth of Smart Phones in VANET EnvironmentShih, Yuan-Bin 08 August 2011 (has links)
none
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The Scheduling Policy with Bandwidth Balancing for Video-on-Demand SystemsSung, Hsin-Hung 24 August 2005 (has links)
As streaming video and audio over the Internet become popular, the deployment of a large-scale multimedia streaming application requires an enormous amount of server and network resources. In a video-on-demand environment, batching of video requests are often used to reduced I/O demand and improve throughput. Since users may leave if they experience long waits, a good video scheduling policy needs to consider not only the batch size but also the user defection probabilities and wait times. The common scheduling policies are the first-come-first-served (FCFS), the maximum queue length (MQL), and the maximum factored queue length (MFQL). But these schemes may choose the same video and serve the same video requests. Users choosing other video can not receive the video segment and may leave after waiting a long time.
In this paper, we propose a batching policy that schedules the video with the concept of the bandwidth balancing scheme in DQDB networks. We refer to this as the SPBB policy. Our goal is to make sure that users can get the video segment and don¡¦t leave the video-on-demand system.
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A CR-LDP Based Bandwidth Preemption with Negotiation Mechanism in MPLS NetworksChen, Ching-Yuan 21 August 2001 (has links)
In MPLS networks, CR-LDP (Constraint-Based Routed Label Distribution Protocol) provides traffic engineering and QoS (Quality of Service) by distributing labels along the path. One of the innovative ideas in CR-LDP is right in the capability of bandwidth preemption. Bandwidth preemption allows a high-priority traffic flow to pre-empt the low-priority traffic flow when there is not enough bandwidth for conveying the high-priority flow. However, it is not effective in assuring QoS by simply pre-empting the low-priority flow.
Therefore, in the thesis, we present a bandwidth preemption with negotiation (BPN) architecture for MPLS networks. In BPN, a high-priority flow will have to negotiate the bandwidth with Ingress Switch Router (ISR) before it can actually pre-empt the bandwidth being used by the low-priority flow. A network link-state database in ISR is designed to record the remaining bandwidth for each priority class. ISR determines whether a high-priority flow can pre-empt a low-priority flow based on the condition that the low-priority flow is possible to switch to other paths with an equal bandwidth along the path.
In order to evaluate the performance of our proposed BPN mechanisms, we modify the MNS (MPLS Network Simulator) by adding a bandwidth negotiation module. For the comparisons, we design two topologies for simulating the proposed BPN and the traditional bandwidth preemption with force mode. It is observed that the BPN have exhibited better performance in average throughput and packet loss rate than the traditional bandwidth preemption, not matter either a complex or a regular topology is used.
Finally, we analyze the BPN algorithm complexity by some network parameters, and compare the complexity with that of traditional bandwidth preemption
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