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In order to provide scalable live streaming services, we propose an Interoverlay Optimization scheme, IOO. Instead of selecting better paths in the same overlay, IOO constructs efficient paths using peers in different overlays so as to 1) improve global resource utilization of peer-to-peer (P2P) streaming networks, 2) assign resources based on their locality and delay, 3) guarantee streaming service quality by using the nearest peers, even when such peers might belong to different overlays, and 4) balance the load among the group (streaming overlay) members. We compare the performance of IOO with existing approaches through trace-driven simulations. Results show that IOO outperforms previous schemes in terms of resource utilization and the quality of service (QoS) of streaming services. The IOO scheme has been implemented in an Internet-based live streaming system, called AnySee. AnySee was successfully released in the summer of 2004 in the China Educational Research Network (CERNET). More than 60,000 users enjoy massive entertainment programs, including TV programs, movies, and academic conferences videos. [ABSTRACT FROM AUTHOR]

Wireless sensor networks (WSNs) have attracted intense interest due to their extensible capability. In this paper, we attempt to answer a fundamental but practical question: "how should we deploy these nodes?" In most current designs, sensor nodes are randomly or uniformly distributed because of their simplicity. However, the node deployment has a great impact on the performance of WSNs. Instead of maintaining the coverage for some snapshots of a WSN, it is essential that we can provide a continuous coverage in the whole lifecycle of the WSN. We will exhibit the weakness of the uniform distribution by disclosing the fatal sink routing-hole problem. To address this problem, we propose a non-uniform, power-aware distribution scheme. Our analysis and simulation results show that the power-aware deployment scheme can significantly improve the long-term network connectivity and service quality. [ABSTRACT FROM AUTHOR]

In unstructured peer-to-peer (P2P) systems, the mechanism of a peer randomly joining and leaving a P2P network causes a topology mismatch between the P2P logical overlay network and the physical underlying network, incurring a large volume of redundant traffic in the Internet. In order to alleviate the topology mismatch problem, we propose Adaptive Connection Establishment (ACE), an algorithm for building an overlay multicast tree among each source node and the peers within a certain diameter from the source peer and further optimizing the neighbor connections that are not on the tree while retaining the search scope. Our simulation study shows that this approach can effectively solve the mismatch problem and significantly reduce P2P traffic. We further study the trade-offs between the topology optimization rate and the information exchange overhead by changing the diameter used to build the tree. [ABSTRACT FROM AUTHOR]

Abstract: In a hybrid peer-to-peer (P2P) system, flooding and DHT are both employed for content locating. The decision to use flooding or DHT largely depends on the population of desired data. Previous works either use local information only, or do not consider dynamic factors of P2P systems. In this paper, we propose a Popularity Adaptive Search method for Hybrid (PASH) protocol. By dynamically estimating the content popularity, PASH properly selects search methods so as to efficiently saves query traffic cost and response time. We evaluate PASH through synthetic and trace-driven simulations. The results show that PASH outperforms existing approaches and it also scales well. [Copyright &y& Elsevier]