Content Distribution by Multiple Multicast Trees and Intersession Cooperation: Optimal Algorithms and Approximations

In traditional massive content distribution with multiple sessions, the sessions form separate overlay networks and operate independently, where some sessions may suffer from insufficient resources even though other sessions have excessive resources. To cope with this problem, we consider the universal swarming approach, which allows multiple sessions to cooperate with each other. We formulate the problem of finding the optimal resource allocation to maximize the sum of the session utilities and present a subgradient algorithm which converges to the optimal solution in the time-average sense. The solution involves an NP-hard subproblem of finding a minimum-cost Steiner tree. We cope with this difficulty by using a column generation method, which reduces the number of Steiner-tree computations. Furthermore, we allow the use of approximate solutions to the Steiner-tree subproblem. We show that the approximation ratio to the overall problem turns out to be no less than the reciprocal of the approximation ratio to the Steiner-tree subproblem. Simulation results demonstrate that universal swarming improves the performance of resource-poor sessions with negligible impact to resource-rich sessions. The proposed approach and algorithm are expected to be useful for infrastructure-based content distribution networks with long-lasting sessions and relatively stable network environment

Random Approach to Optimization of Overlay Public-Resource Computing Systems

The growing need for computationally demanding systems triggers the development of various network-oriented computing systems organized in a distributed manner. In this work we concentrate on one kind of such systems, i.e. public-resource computing systems. The considered system works on the top of an overlay network and uses personal computers and other relatively simple electronic equipment instead of supercomputers. We assume that two kinds of network flows are used to distribute the data in the public-resource computing systems: unicast and peer-to-peer. We formulate an optimization model of the system. After that we propose random algorithms that optimize jointly the allocation of computational tasks and the distribution of the output data. To evaluate the algorithms we run numerical experiments and present results showing the comparison of the random approach against optimal solutions provided by the CPLEX solver

Semi-fluid: A Content Distribution Model For Faster Dissemination Of Data

Tesis ini mencadangkan serta melaksanakan suatu model agihan kandungan bagi mengurangkan atau meminimumkan kelengahan penyaluran data sebaya. Buat masa ini, agihan kandungan dalam rangkaian tindihan-atas adalah berdasarkan dua model berikut: model Kelulan dan model Bendalir. This thesis proposes and implements a novel content distribution model for reducing or minimizing delay in data dissemination

WiLiTV: A Low-Cost Wireless Framework for Live TV Services

With the evolution of HDTV and Ultra HDTV, the bandwidth requirement for IP-based TV content is rapidly increasing. Consumers demand uninterrupted service with a high Quality of Experience (QoE). Service providers are constantly trying to differentiate themselves by innovating new ways of distributing content more efficiently with lower cost and higher penetration. In this work, we propose a cost-efficient wireless framework (WiLiTV) for delivering live TV services, consisting of a mix of wireless access technologies (e.g. Satellite, WiFi and LTE overlay links). In the proposed architecture, live TV content is injected into the network at a few residential locations using satellite dishes. The content is then further distributed to other homes using a house-to-house WiFi network or via an overlay LTE network. Our problem is to construct an optimal TV distribution network with the minimum number of satellite injection points, while preserving the highest QoE, for different neighborhood densities. We evaluate the framework using realistic time-varying demand patterns and a diverse set of home location data. Our study demonstrates that the architecture requires 75 - 90% fewer satellite injection points, compared to traditional architectures. Furthermore, we show that most cost savings can be obtained using simple and practical relay routing solutions

A heterogeneous peer-to-peer network testbed

In this paper, we describe a heterogeneous peer-to-peer network testbed, which is developed as part of a joint research project to investigate novel resource discovery and content distribution protocols in a heterogeneous wired/wireless environment. We describe the testbed requirements, the testbed architecture, the multi-functional wireless node, and the software architecture. We also describe some of the proposed protocols to be developed and tested on the testbed. © 2009 IEEE.published_or_final_versionThe 1st International Conference on Ubiquitous and Future Networks (ICUFN 2009), Hong Kong, 7-9 June 2009. In Proceedings of the 1st ICUFN, 2009, p. 46-5