Yuhui Zhao

Multiagent System for Reputation--based Web Services Selection

QoS-based service selection mechanisms will play an essential role in service-oriented architectures, as e-business applications want to use services that most accurately meet their requirements. However, current techniques provide no support for actually making rational selections. In this paper, we develop a multiagent framework for QoS-based Web services selection, through a combination of the respective merits of agent and service-oriented to enables dynamic and efficient delivery of composite Web services. We present a service-oriented distributed reputation assessment algorithm as a QoS support module in the framework. We give an example application and some preliminary results

Interdomain traffic control over multiple links based on genetic algorithm

Network operators must have control over the flow of traffic into, out of, and across their networks. Usually, changes of interdomain traffic affect intradomain traffic in other domains. We propose an approach to control interdomain traffic over multiple links based on prefixes. Transit Autonomous System (AS) measure the flow of traffic and cooperate with other ASes in balancing interdomain traffic. Using the data of interdomain traffic and intradomain traffic measured in transit networks, the approach evaluates the cost of transit networks. We present a genetic algorithm to specify a link for prefix in AS neighbors with the objective of minimizing costs and configuration changes. In order to decrease the complex of calculation, we analysis the distribution of traffic and propose an approach to select popular prefixes. A example verify the availability and effectiveness of the algorithm.

A qos-satisfied interdomain overlay multicast algorithm for live media service grid

We are developing a live media service Grid(LMSG) as an extensible middleware architecture for supporting live media applications in a grid computing environment. The LMSG service was provided by the service brokers nodes(SvBs) which are strategically deployed by Internet Service Providers (ISPs). This paper mainly presents a QoS-satisfied interdomain overlay multicast algorithm (QIOM), which is the key to organize the SvBs to build a QoS-aware multicast service tree and the most important part of LMSG middleware. It is an overlay based the multicast connection solution for live media relay in different ASes and can overcome the difficulties of Border Gateway Multicast Protocol. The simulation results show that the QIOM algorithms can effectively find and provide QoS-assured overlay services and balance the overlay traffic burden among the SvBs.

Reputation-based Semantic Service Discovery

In this paper, we present a framework to facilitate Reputation-based service selection with reputation management, which has three key features. First, we use a structured overlay network as the decentralized service repository system for improved efficiency. Second, we propose an adaptive QoS-aware service discovery approach. Then, we present a service-oriented distributed reputation assessment algorithm based on users feedback. We test our approach on a simple, yet realistic example, and the preliminary results demonstrate that our implementation provides a practical solution.

A Real-time Streaming Media File Sharing Mechanism Based on P2P and SIP

P2P systems have high scalability, robustness and fault tolerance because of its no centralized server and the network self-organized itself As the standard protocol for VoIP and NGN, SIP is a general protocol for establishing and controlling multimedia session. In this paper, we proposed a real-time streaming media sharing mechanism based on P2P and SIP, which uses Chord as the underlying distributed hash table (DHT). We use the advanced peer and piece selection algorithm to solve the real time media stream transmission. We have a redundancy design on the Tracker server to solve the Tracker server failure and bottleneck problem. The P2P combined with SIP real time stream transport mechanism supports user registration, media resource location, media streaming session establishment, and real-time media streaming playback online

ALMSC: An Application layer multicast based SIP conference model

We present the design of session initiation protocol (SIP) conference based on application layer multicast. Based on the character of SIP conference, we offered a new algorithm to create an application layer multicast tree. In this application layer multicast tree, the two key factors of both bandwidth and delay in streaming media are taken into consideration. The simulation and the experiments show that the design is practical and has a great improvement on the video quality and scalability

A genetic algorithm in layered overlay multicast network

We present a new architecture named layered overlay multicast network (LOMN) for large-scale interdomain live media applications by strategically deploying the service brokers (SvBs) among the ASes. Genetic algorithm is selected to build the core multicast tree under delay constraint (CMTDC) for LOMN and propose a novel chromosomal coding scheme which uses destination-oriented method to represent chromosomes and general genetic and chromosome repair operators. The experimental results show that our solution model can obtain a near optimal solution for building the core multicasting tree.

An agent-based services composition framework for ubiquitous media

Ubiquitous media aims to provide media services anytime and anywhere. Software agents are one of the building blocks of ambient intelligence and pervasive computing. In this paper, we use a structured overlay network as the decentralized service repository system for improved efficiency. We present an agent-based services composition framework for ubiquitous media, through a combination of the respective merits of agent and service-oriented to enables dynamic and efficient delivery of media composite services. We advocate that a service-centric context promotes media applications that allow service adaptability, deal with service availability, and support on-the-fly service composition. Finally, we present an example of our system in the context of streaming video playback involving a series of transcoding services and a mobile client.

BSMON: bandwidth-satisfied multicast in overlay network for large-scale live media applications

ISP needs multicast service to save the bandwidth and costs when more and more large-scale live media applications are emerging in the Internet. There are no proper methods because the localization of IP multicast and Application Level Multicasts. Here we present a suggestion called Layered Overlay Multicast Network (LOMN) for the ISPs live media services. LOMN set up the core multicast tree for live streams by strategically deploying the service brokers (SvBs) and the algorithm of Bandwidth-satisfied multicast in overlay network (BSMON), which is to set up an efficient QoS-satisfied overlay connections between SvBs, balance the overlay traffic and the load on the SvBs. we address critical issues such as scalability, low delays, little delay variations and minimal the cost of multicast tree.