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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Design, modelling and analysis of the balanced gamma multicast switch for broadband communications /

Li, Cheng, January 2004 (has links)
Thesis (Ph.D.)--Memorial University of Newfoundland, 2004. / Bibliography: leaves 212-222.
42

QOS multimedia multicast routing a component based primal dual approach /

Hussain, Faheem A. January 2006 (has links)
Thesis (M.S.)--Georgia State University, 2006. / Title from title screen. Alexander Zelikovsky, committee chair; Anu Bourgeois, Saeid Belkasim, committee members. Electronic text (59 p. : ill. (some col.)) : digital, PDF file. Description based on contents viewed June 28, 2007. Includes bibliographical references (p. 58-59).
43

On iBGP Multicasting in Software Defined Networks

Bassey, Ukemeobong Okon January 2017 (has links)
In the Internet today, learnt prefixes are forwarded within autonomous systems (ASs) over internal Border Gateway Protocol (iBGP) sessions. Existing schemes for iBGP routing include the full-mesh (FM) solution, route reflection (RR) solution and confederation. Optimal prefix routing and route diversity are the main strength of the FM solution. However, it is rarely employed in a large networks due to its deficiency in aspects including scalability and large Routing Information Base (RIB) size requirement of routers. This is due to the fact that routers in this topology are required to peer with every other router within the AS. To combat these challenges, the RR scheme provides solution for scalability by decreasing the iBGP sessions requirement. Notwithstanding, the RR solution has its own challenges which includes reduced route diversity, introduction of divergence and forwarding anomalies. Also, the FM optimality may be lost since the Route Reflectors are responsible for reflecting the learnt prefixes to their corresponding clients based on its partial view of the network. The concept of Software Defined Networking (SDN) entails decoupling of the control plane from the forwarding plane such that the control plane is logically centralized benefiting from an overall knowledge of the network for decision making. In this work, we propose a solution based on multicasting which employs relay nodes in the iBGP message dissemination. Our solution brings session management scalability and minimization of duplicate prefix announcement through elimination of peer sessions deemed unnecessary. SDN controller is employed to configure and coordinate the multicast tree.
44

Relay-aided communications with partial channel state information

Yazdan Panah, Ali 21 October 2011 (has links)
Modern wireless communication systems strive to enable communications at high data rates, over wide geographical areas, and to multiple users. Unfortunately, this can be a daunting task in practice, as natural laws governing the wireless medium may hinder point-to-point transmissions. Communications over large distances (path loss), and physical obstructions in line-of-sight signals (shadowing) are prime examples of such impediments. One promising solution is to deploy intermediary terminals to help reestablish such broken point-to-point communication links. Such terminals are called relay nodes, and the corresponding systems are referred to as being relay-aided. As in the case of point-to-point communication, design of efficient transmission and reception techniques in relay-aided systems depends on the availability of propagational channel state information. In practice, such information is only accurate to a certain degree which is governed by overhead constraints, feedback delay, and channel fluctuations due to mobility. Understanding the impacts of such partial channel state information, and devising transmission and reception methods based on such understandings, is the main topic of this dissertation. The transmission protocol classifies relays as either one-way, where the relay receives signals from one terminal, or two-way, where the relay receives signals from more than one terminal. Designs and solutions for both one- and two-way relaying systems are presented in this dissertation. Emphasis is placed on two-way relaying systems given their superior efficiency in utilizing channel resources. For one-way relaying this dissertation presents power loading strategies for multiuser-multicast systems derived based on the availability of full or partial channel state information at the terminals. In the case of two-way relaying, both single and multi-user systems are analyzed. For single-user two-way relaying, this dissertation presents optimal methods of acquiring partial channel state information via pilot-aided channel estimation methods. This includes an analysis of the effects of channel estimation upon the system sum-rate. Also, the design of channel equalizers exhibiting robustness to partial channel state information is proposed. For multi-user two-way relaying, this dissertation presents several precoding strategies at the relay terminal(s) to combat the effects co-channel interference in light of the existence of self-interference inherent to two-way relaying operations. / text
45

Multirate Multicasting with Network Coding

Lakshminarayana, Subhash 24 September 2009 (has links)
No description available.
46

Multicast techniques for bandwidth-demanding applications in overlay networks

Tsang, Cheuk-man, Mark., 曾卓敏. January 2008 (has links)
published_or_final_version / abstract / Computer Science / Doctoral / Doctor of Philosophy
47

Scalable content distribution in overlay networks

Kwan, Tin-man, Tony., 關天文. January 2007 (has links)
published_or_final_version / abstract / Electrical and Electronic Engineering / Master / Master of Philosophy
48

Security and efficiency concerns with distributed collaborative networking environments

Felker, Keith A. 03 1900 (has links)
Approved for public release, distribution unlimited / The progression of technology is continuous and the technology that drives interpersonal communication is not an exception. Recent technology advancements in the areas of multicast, firewalls, encryption techniques, and bandwidth availability have made the next level of interpersonal communication possible. This thesis answers why collaborative environments are important in today's online productivity. In doing so, it gives the reader a comprehensive background in distributed collaborative environments, answers how collaborative environments are employed in the Department of Defense and industry, details the effects network security has on multicast protocols, and compares collaborative solutions with a focus on security. The thesis ends by providing a recommendation for collaborative solutions to be utilized by NPS/DoD type networks. Efficient multicast collaboration, in the framework of security is a secondary focus of this research. As such, it takes security and firewall concerns into consideration while comparing and contrasting both multicast-based and non-multicast-based collaborative solutions.
49

System evaluation of hardware and software for a streaming multimedia server using the multicasting protocol

Carls, John W. 09 1900 (has links)
Approved for public release; distribution is unlimited / The next step in the evolution of services provided on an intranet or the internet will be distributed or distance learning with collaboration among peers. Currently, this is done on a one-to-one basis. To expand to a one-tomany collaboration environment, there needs to be a server distributing the multimedia content without creating additional network traffic even though many users are accessing or viewing the multimedia content. Multicasting allows many users to view multimedia content without creating additional network traffic. There is a server providing multimedia content to a multicast address so users may access it. This thesis defines metrics and conducts a comparison of different servers capable of distributing multimedia content using the multicasting protocol. / Lieutenant, United States Navy
50

Admission control and radio resource allocation for multicasting over high altitude platforms

Ibrahim, Ahmed 15 August 2016 (has links)
In this thesis, optimization techniques for a joint admission control and radio resource allocation are developed for multicasting over high altitude platforms. First, a primary system model in a multicellular high altitude platform system is considered, in which each user can receive any requested multicast session in its cell from no more than only one HAP antenna simultaneously. All the users have equal priority for admission. The users are selected to join the respective multicast groups and the power, subchannels and time slots are allocated such that the spectrum utilization is maximized while satisfying the quality of service requirements. Lagrangian relaxation and the subgradient algorithm are used to obtain solution bounds for the primary system model problem formulation. These bounds were then used in the branch and bound algorithm for pruning of nodes. The numerical results illustrate the goodness of the bounds for different constraint set dualizations and for different subgradient step size rules. The system model is then extended to allow the multicast group users to receive a session's transmission from more than one antenna simultaneously at different frequencies. This also allows the user to receive multicast sessions transmitted in neighboring cells too, not just those transmitted in the cell which the user resides in. The users have different priority levels of admission and the objective is to maximize the admission of highest priority users to the system. A much efficient formulation is obtained for the extended model in terms of size, as compared to the primary model. Linear outer approximation using McCormick underestimators are used for the relaxation of the mixed binary quadratically constrained problem. The solution method is based on branch and cut scheme in which cutting planes, domain propagation and heuristics are integrated. Various branching schemes are considered and a presolving reformulation linearization scheme for a specific set of quadratic constraints is considered. The numerical experiments compare the performances in terms of the duality gap, number of nodes, number of iterations, the number of iterations per node, the time needed to obtain the first feasible solution and the percentage of instances a feasible solution was found. / October 2016

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