Collaborative work model based on peer-to-peer network

In this paper, we incorporated peer-to-peer (P2P) concept with agent technology and put forward a collaborative work model based on peer-to-peer network (P2PCWM) after investigating into business demands of modern enterprises and problems prevailing in mainstream collaborative work systems based on central server. Theoretically, the P2PCWM can effectively overcome the problems in a conventional system with a central server and meet the practical demands of modern businesses. It is distinguished from other systems by its features of equality, openness, promptness, fairness, expandability and convenience.     

Hybrid ants-like search algorithms for P2P media streaming distribution in ad hoc networks

Media streaming delivery in wireless ad hoc networks is challenging due to the stringent resource restrictions,po-tential high loss rate and the decentralized architecture. To support long and high-quality streams,one viable approach is that a media stream is partitioned into segments,and then the segments are replicated in a network and served in a peer-to-peer(P2P) fashion. However,the searching strategy for segments is one key problem with the approach. This paper proposes a hybrid ants-like search algorithm(HASA) for P2P media streaming distribution in ad hoc networks. It takes the advantages of random walks and ants-like algorithms for searching in unstructured P2P networks,such as low transmitting latency,less jitter times,and low unnecessary traffic. We quantify the performance of our scheme in terms of response time,jitter times,and network messages for media streaming distribution. Simulation results showed that it can effectively improve the search efficiency for P2P media streaming distribution in ad hoc networks.     

Study on semantic-oriented hybrid indexing strategy of resource metadata in peer-to-peer network

INTRODUCTION In some large scale corporations and virtual or-ganization environment (education system, military organizations, etc.), much electronics information resources are distributed physically and diverse in types. Each unit of an organization manages some resources respectively, according to the domain knowledge or the particular mission. In technical aspect, each unit is a node working independently in the information network. These nodes can join or leave the network at any tim…     

P2P对等网在互联网上的应用和技术探讨

P2P即Peer to Peer,又称为对等连接或对等网络,本文主要阐述了P2P网与互联网在硬件连 接、信息控制技术方面的区别,并给出了一个可实现P2P应用的流程图。     

Content subscribing mechanism in P2P streaming based on gamma distribution prediction

P2P systems are categorized into tree-based and mesh-based systems according to their topologies. Mesh-based systems are considered more suitable for large-scale Internet applications, but require optimization on latency issue. This paper proposes a content subscribing mechanism (CSM) to eliminate unnecessary time delays during data relaying. A node can send content data to its neighbors as soon as it receives the data segment. No additional time is taken during the interactive stages prior to data segment transmission of streaming content. CSM consists of three steps. First, every node records its historical segments latency, and adopts gamma distribution, which possesses powerful expression ability, to express latency statistics. Second, a node predicts subscribing success ratio of every neighbor by comparing the gamma distribution parameters of the node and its neighbors before selecting a neighbor node to subscribe a data segment. The above steps would not increase latency as they are executed before the data segments are ready at the neighbor nodes. Finally, the node, which was subscribed to, sends the subscribed data segment to the subscriber immediately when it has the data segment. Experiments show that CSM significantly reduces the content data transmission latency.     

基于流状态统计的P2P流量识别

近几年来,P2P(Peer-to-Peer,对等网络)作为一项全新的网络技术得到飞速发展。有关调查表明,P2P业务已悄然占据了互联网业务总量的60%～80%,成为杀手级宽带互联网的应用。     

非结构化P2P网络搜索技术研究

P2P文件共享首先要解决文件定位的问题。理论上,P2P搜索技术的搜索范围将在几秒钟内以几何级数增长,几分钟内     

视频潮涌校园网

2006年10月,Google宣布以价值16.5亿美元的股票收购YouTube,这一消息使网络视频应用备受瞩目,一时间引发全球范围的视频热潮。2007年,网络视频的关注度持续上升。2月,紧随Google,百度推出视频搜索服务。3月,成立2年的基于P2P技术的视频网站PPStream取得千万美元融资。4月,视频分享网站土豆网第三轮融资获2000万美元,较二次融资增长超过100%。7月,搜狐宣布和央视国际合作,对央视13个频道的100多个节目进行直播、联播、互动。搜狐相关人员表示,未来双方还可能进行基于技术、内容等方面的合作。这被看作是传统视频内容提供商与网站在视频方面开始进行大规模合作的标志。有数据显示,去年全国网络视频用户达到6300万,占网民人数的47%。专家预测说,该比例到2010年有望达到80%。     

EFF：技术无边法有界

互联网上人们不仅仅会碰到各类技术问题和理论问题，还会碰到各式各样的法律问题，比如网站中用户信息是否允许透露给第三方、P2P是否合法等，当技术和法律发生冲突的时候，如何保护普通民众的权利，这就是电子前沿基金会研究的问题。     

Rate-distortion optimized bitstream switching for peer-to-peer live streaming

Peer-to-peer （P2P） technology provides a cost-effective and scalable way to distribute video data. However, high heterogeneity of the P2P network, which rises not only from heterogeneous link capacity between peers but also from dynamic variation of available bandwidth, brings forward great challenge to video streaming. To attack this problem, an adaptive scheme based on rate-distortion optimization （RDO） is proposed in this paper. While low complexity RDO based frame dropping is exploited to shape bitrate into available bandwidth in peers, the streamed bitstream is dynamically switched among multiple available versions in an RDO way by the streaming server. Simulation results show that the proposed scheme based on RDO achieves great gain in overall perceived quality over simple heuristic schemes.     

Multiple description coding with spatial-temporal hybrid interpolation for video streaming in peer-to-peer networks

INTRODUCTION Multimedia services over the Internet are be- coming popular due to the widespread deployment of broadband access. However, the conventional cli- ent-server architecture severely limits the number of simultaneous users, especially for bandwidth inten- sive applications such as video streaming. P2P net- works, on the other hand, offer a solution to the scalability problem. As a node joins a P2P network, it not only consumes resources but also contributes its bandwidth or comp…     

BulkTree: an overlay network architecture for live media streaming

Peer-to-peer (P2P) systems are now very popular. Current P2P systems are broadly of two kinds, structured and unstructured. The tree structured P2P systems used technologies such as distributed hash tables (DHT) and hierarchical clustering can search the required target quickly, however, in a tree, the internal node has a higher load and its leave or crash often causes a large population of its offspring's problems, so that in the highly dynamic Internet environment the tree structure may still suffer frequent breaks. On the other hand, most widely used unstructured P2P networks rely on central directory servers or massive message flooding, clearly not scalable. So, we consider both of the above systems' advantages and disadvantages and realize that in the P2P systems one node may fail easily, but that when a number of nodes organized as a set, which we call "super node", the set is robust. Super nodes can be created and updated aware of topology-aware, and used with simple protocol such as flooding or "servers" to exchange information. Furthermore the entire robust super node can be organized into exquisite tree structure. By using this overlay network architecture, P2P systems are robust, efficient, scalable and secure. The simulation results demonstrated that our architecture greatly reduces the alteration time of the structure while decreasing the average delay time, compared to the common tree structure.     

基于格形因子搜索的部分传输序列方法

为了得到部分传输序列降低OFDM信号峰均比方案中复杂度和性能之间的良好折衷,提出了一种基于格形结构的部分传输序列因子的搜索方法.这种格形搜索有一个可变的约束长度LC,1≤LC≤V-1,V为部分传输序列子块的数目.该方法通过搜寻格形结构中可能的路径来决定部分传输序列的因子,而这些路径通过改变LC个相邻因子的值得到.格形搜索可看作一个统一的传输序列因子搜索模型,当LC=V-1,为全局搜索;当LC=1,为单步迭代搜索.采用不同的约束长度,格形搜索在抑制峰均比方面呈现出不同的性能,LC 越大其性能越好,而LC=V-1对应最优的结果.同时较大的LC需要更多的计算.这些结论有助于在复杂度和性能之间找到一个好的折衷.     

基于PLSA的面向用户的网络搜索

针对当前的搜索引擎提供面向查询、而非面向用户的服务,从而导致搜索引擎无法满足用户个性化的需求这一问题,提出了一种基于PLSA的新方法,将面向查询词的搜索转变成面向用户的搜索.首先,通过分析用户查询历史和浏览记录建立代表用户模型的用户兴趣向量,在用户发出查询时用户的查询词根据用户兴趣向量被映射到兴趣分类上,最终根据面向用户排序算法将返回结果列表重新排序.实验表明该面向用户搜索系统能够充分考虑用户的偏好,从而更好地满足不同用户的信息需求.     

Deadline-aware network coding for video on demand service over P2P networks

INTRODUCTION With the widespread deployment of broadband access, Video-on-Demand (VoD) streaming on the Internet has received increasing attention recently. In VoD service, video streams are delivered to asyn- chronous users with low delay and VCR-like opera- tion support (e.g., pause, fast-forward, and rewind). However, streaming to a large population of clients is very challenging due to the limited server capacity and little deployment of IP multicast in today’s Internet (Quinn a…     

Control DHT maintenance costs with session heterogeneity

The maintaining overheads of Distributed Hash Table (DHT) topology have recently received considerable attention.This paper presents a novel SHT (Session Heterogeneity Topology) model, in which DHT is reconstructed with session heterogeneity. SHT clusters nodes by means of session heterogeneity among nodes and selects the stable nodes as the participants of DHT. With an evolving process, this model gradually makes DHT stable and reliable. Therefore the high maintaining overheads for DHT are effectively controlled. Simulation with real traces of session distribution showed that the maintaining overheads are reduced dramatically and that the data availability is greatly improved.     

SSABC:一种基于能力的超级节点选择算法

结合P2P和网格的特点,提出了从P2P与网格混合的分布式网络中选择超级节点的算法SSABC．算法使用网格信息监控系统（MDS）获取节点资源的动态属性信息,如可用带宽、空闲CPU、可用内存、当前连接数及在线时间等,根据以上属性计算节点的能力．当有新节点加入且超级节点均饱和时,从新节点或已加入节点中选择能力最高的作为新的超级节点．通过理论分析和仿真实验表明,基于能力选择的超级节点与随机选择的超级节点相比,提高了资源的查询成功率,缩短了平均查询跳数,并能够在超级节点饱和时均衡网络负载．当网络中节点数发生变化时,以上结论依然成立,说明了算法的可行性和稳定性．