Delay-Constrained Multicast Routing Algorithm Based on Average Distance Heuristic

Multicast is the ability of a communication network to accept a single message from an application and to deliver copies of the message to multiple recipients at different location. With the development of Internet, Multicast is widely applied in all kinds of multimedia real-time application: distributed multimedia systems, collaborative computing, video-conferencing, distance education, etc. In order to construct a delay-constrained multicast routing tree, average distance heuristic (ADH) algorithm is analyzed firstly. Then a delay-constrained algorithm called DCADH (delay-constrained average distance heuristic) is presented. By using ADH a least cost multicast routing tree can be constructed; if the path delay can't meet the delay upper bound, a shortest delay path which is computed by Dijkstra algorithm will be merged into the existing multicast routing tree to meet the delay upper bound. Simulation experiments show that DCADH has a good performance in achieving a low-cost multicast routing tree.Comment: 8 Pages, IJCNC Journal 201

The Power of Dynamic Distance Oracles: Efficient Dynamic Algorithms for the Steiner Tree

In this paper we study the Steiner tree problem over a dynamic set of terminals. We consider the model where we are given an $n$-vertex graph $G=(V,E,w)$ with positive real edge weights, and our goal is to maintain a tree which is a good approximation of the minimum Steiner tree spanning a terminal set $S \subseteq V$, which changes over time. The changes applied to the terminal set are either terminal additions (incremental scenario), terminal removals (decremental scenario), or both (fully dynamic scenario). Our task here is twofold. We want to support updates in sublinear $o(n)$ time, and keep the approximation factor of the algorithm as small as possible. We show that we can maintain a $(6+\varepsilon)$-approximate Steiner tree of a general graph in $\tilde{O}(\sqrt{n} \log D)$ time per terminal addition or removal. Here, $D$ denotes the stretch of the metric induced by $G$. For planar graphs we achieve the same running time and the approximation ratio of $(2+\varepsilon)$. Moreover, we show faster algorithms for incremental and decremental scenarios. Finally, we show that if we allow higher approximation ratio, even more efficient algorithms are possible. In particular we show a polylogarithmic time $(4+\varepsilon)$-approximate algorithm for planar graphs. One of the main building blocks of our algorithms are dynamic distance oracles for vertex-labeled graphs, which are of independent interest. We also improve and use the online algorithms for the Steiner tree problem.Comment: Full version of the paper accepted to STOC'1

GA-based heuristic algorithms for bandwidth-delay-constrained least-cost multicast routing

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Design optimal de réseau multipoint survivable

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

Managing dynamic groups in QoS and overlay multicasting

Multicasting has been the most popular mechanism for supporting group communication, wherein group members communicate through a multicast data distribution tree that spans all the members of the group. In a dynamic multicast session, members join/leave the group using graft/prune mechanisms, based on locally optimal paths, which would eventually degenerate the quality of the multicast tree. Therefore, efficient mechanisms need to be invoked periodically to maintain the cost of the multicast tree near optimal. However, tree maintenance would result in service disruption for the session. Therefore, there exists a trade-off between minimizing tree cost and minimizing service disruption. The goal of this dissertation is to develop and analyze a set of efficient tree maintenance techniques that aim to balance this tradeoff in QoS and overlay multicasting. To achieve this goal, the dissertation makes three key contributions. First, the design of scalable protocols, viz. tree migration and tree evolution, for maintaining QoS multicast trees. Second, the design of an efficient strategy, called partial protection approach, and its implementation methods for member join problem with path reliability being a QoS constraint. Third, the design of an efficient tree maintenance algorithm, based on the idea of mesh-tree interactions, for end-system based overlay multicasting. The proposed tree maintenance solutions have been evaluated and analyzed through a combination of simulation and analytical studies. The studies show that the proposed solutions indeed achieve a good balance between tree cost and service disruption competitively

A constrained steiner tree approach for reconstructions of multicast trees.

Sun Tong.Thesis (M.Phil.)--Chinese University of Hong Kong, 2004.Includes bibliographical references (leaves 77-81).Abstracts in English and Chinese.Chinese Abstract --- p.IAbstract --- p.IIAcknowledgements --- p.IIIList of Contents --- p.IVList of Figures --- p.VIIChapter Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Multicast Routing Problem --- p.1Chapter 1.2 --- Constrained multicast routing problem and SSRA algorithm --- p.4Chapter 1.3 --- Thesis organization --- p.7Chapter Chapter 2 --- Constrained Multicast Routing Algorithms --- p.8Chapter 2.1 --- Steiner tree heuristic --- p.8Chapter 2.1.1 --- Shortest Paths Heuristic --- p.9Chapter 2.1.2 --- Distance Network Heuristic --- p.10Chapter 2.2 --- Review of existing constrained multicast routing algorithms --- p.10Chapter 2.2.1 --- Static group member --- p.10Chapter 2.2.2 --- Dynamic group member --- p.14Chapter 2.2.2.1 --- Non-rearrangeable --- p.15Chapter 2.2.2.2 --- Rearrangeable --- p.23Chapter Chapter 3 --- Small Scale Rearrangement Algorithm for Multicast Routing --- p.32Chapter 3.1 --- Problem formulation --- p.32Chapter 3.1.1 --- Network Model --- p.32Chapter 3.1.2 --- Problem Specification --- p.33Chapter 3.1.3 --- Definitions and Notations --- p.36Chapter 3.2 --- Local Checking Scheme (LCS) --- p.37Chapter 3.3 --- Small Scale Rearrangement Algorithm (SSRA) for Multicast Routing --- p.41Chapter 3.3.1 --- Static group membership --- p.42Chapter 3.3.2 --- Dynamic group membership --- p.43Chapter 3.3.2.1 --- Node addition --- p.44Chapter 3.3.2.2 --- Node removal --- p.44Chapter 3.3.2.3 --- General steps --- p.45Chapter 3.3.2.4 --- Example --- p.47Chapter Chapter 4 --- Analysis --- p.50Chapter Chapter 5 --- Simulations --- p.54Chapter 5.1 --- Simulation Model --- p.54Chapter 5.2 --- Simulation Parameters Parameter Default Value/Generating Method --- p.56Chapter 5.3 --- Performance Metrics --- p.58Chapter 5.4 --- Discussion of Results --- p.59Chapter 5.4.1 --- Group 1: static group membership --- p.59Chapter 5.4.2 --- Group 2: dynamic group membership --- p.63Chapter 5.4.3 --- Comparison --- p.69Chapter 5.5 --- Implementation Issue --- p.73Chapter Chapter 6 --- Conclusion --- p.75Reference --- p.7

Scalable approaches for DiffServ multicasting

Over the last several years, there has been an explosion in the introduction of new Internet technologies. Whereas the Internet in its original form was a medium primarily for academia and research interests, the Internet has been redefined as business and consumer interests have dominated the focal points of Internet technology. The dominant question facing the Internet today is, how can the network meet the needs of the users and their applications while trying to keep such implementations scalable to the billions of users present on the Internet? Two of the emerging technologies for answering the question are Differentiated Services (DiffServ) and multicasting. Although the two technologies share complementary goals, the integration of the two technologies is a non-trivial issue due to three fundamental conflicts. The three fundamental conflicts are the scalability of per-group state information, sender versus receiver-driven QoS, and resource management. The issues surrounding how to solve these conflicts provide the basis for this dissertation.;In this dissertation, two architectures (DiffServ Multicasting (DSMCast) and Edge-Based Multicasting (EBM)) are proposed to satisfy the requirements for scalable DiffServ multicasting architectures. In addition to the two architectures, this dissertation also presents the first in-depth study regarding single tree support for heterogeneous QoS multicasting. Furthermore, the dissertation proposes a novel application of DSMCast for fault tolerance and management of the DiffServ network. Finally, the dissertation comments on future applications of the architectures and proposes several areas for future research

Unified Role Assignment Framework For Wireless Sensor Networks

Wireless sensor networks are made possible by the continuing improvements in embedded sensor, VLSI, and wireless radio technologies. Currently, one of the important challenges in sensor networks is the design of a systematic network management framework that allows localized and collaborative resource control uniformly across all application services such as sensing, monitoring, tracking, data aggregation, and routing. The research in wireless sensor networks is currently oriented toward a cross-layer network abstraction that supports appropriate fine or course grained resource controls for energy efficiency. In that regard, we have designed a unified role-based service paradigm for wireless sensor networks. We pursue this by first developing a Role-based Hierarchical Self-Organization (RBSHO) protocol that organizes a connected dominating set (CDS) of nodes called dominators. This is done by hierarchically selecting nodes that possess cumulatively high energy, connectivity, and sensing capabilities in their local neighborhood. The RBHSO protocol then assigns specific tasks such as sensing, coordination, and routing to appropriate dominators that end up playing a certain role in the network. Roles, though abstract and implicit, expose role-specific resource controls by way of role assignment and scheduling. Based on this concept, we have designed a Unified Role-Assignment Framework (URAF) to model application services as roles played by local in-network sensor nodes with sensor capabilities used as rules for role identification. The URAF abstracts domain specific role attributes by three models: the role energy model, the role execution time model, and the role service utility model. The framework then generalizes resource management for services by providing abstractions for controlling the composition of a service in terms of roles, its assignment, reassignment, and scheduling. To the best of our knowledge, a generic role-based framework that provides a simple and unified network management solution for wireless sensor networks has not been proposed previously

Design of Overlay Networks for Internet Multicast - Doctoral Dissertation, August 2002

Multicast is an efficient transmission scheme for supporting group communication in networks. Contrasted with unicast, where multiple point-to-point connections must be used to support communications among a group of users, multicast is more efficient because each data packet is replicated in the network – at the branching points leading to distinguished destinations, thus reducing the transmission load on the data sources and traffic load on the network links. To implement multicast, networks need to incorporate new routing and forwarding mechanisms in addition to the existing are not adequately supported in the current networks. The IP multicast are not adequately supported in the current networks. The IP multicast solution has serious scaling and deployment limitations, and cannot be easily extended to provide more enhanced data services. Furthermore, and perhaps most importantly, IP multicast has ignored the economic nature of the problem, lacking incentives for service providers to deploy the service in wide area networks. Overlay multicast holds promise for the realization of large scale Internet multicast services. An overlay network is a virtual topology constructed on top of the Internet infrastructure. The concept of overlay networks enables multicast to be deployed as a service network rather than a network primitive mechanism, allowing deployment over heterogeneous networks without the need of universal network support. This dissertation addresses the network design aspects of overlay networks to provide scalable multicast services in the Internet. The resources and the network cost in the context of overlay networks are different from that in conventional networks, presenting new challenges and new problems to solve. Our design goal are the maximization of network utility and improved service quality. As the overall network design problem is extremely complex, we divide the problem into three components: the efficient management of session traffic (multicast routing), the provisioning of overlay network resources (bandwidth dimensioning) and overlay topology optimization (service placement). The combined solution provides a comprehensive procedure for planning and managing an overlay multicast network. We also consider a complementary form of overlay multicast called application-level multicast (ALMI). ALMI allows end systems to directly create an overlay multicast session among themselves. This gives applications the flexibility to communicate without relying on service provides. The tradeoff is that users do not have direct control on the topology and data paths taken by the session flows and will typically get lower quality of service due to the best effort nature of the Internet environment. ALMI is therefore suitable for sessions of small size or sessions where all members are well connected to the network. Furthermore, the ALMI framework allows us to experiment with application specific components such as data reliability, in order to identify a useful set of communication semantic for enhanced data services