A schema-based P2P network to enable publish-subscribe for multimedia content in open hypermedia systems

Open Hypermedia Systems (OHS) aim to provide efficient dissemination, adaptation and integration of hyperlinked multimedia resources. Content available in Peer-to-Peer (P2P) networks could add significant value to OHS provided that challenges for efficient discovery and prompt delivery of rich and up-to-date content are successfully addressed. This paper proposes an architecture that enables the operation of OHS over a P2P overlay network of OHS servers based on semantic annotation of (a) peer OHS servers and of (b) multimedia resources that can be obtained through the link services of the OHS. The architecture provides efficient resource discovery. Semantic query-based subscriptions over this P2P network can enable access to up-to-date content, while caching at certain peers enables prompt delivery of multimedia content. Advanced query resolution techniques are employed to match different parts of subscription queries (subqueries). These subscriptions can be shared among different interested peers, thus increasing the efficiency of multimedia content dissemination

Peer-to-peer systems for simple and flexible information sharing

Includes abstract.Includes bibliographical references (leaves 76-80).Peer to peer computing (P2P) is an architecture that enables applications to access shared resources, with peers having similar capabilities and responsibilities. The ubiquity of P2P computing and its increasing adoption for a decentralized data sharing mechanism have fueled my research interests. P2P networks are useful for sharing content files containing audio, video, and data. This research aims to address the problem of simple and flexible access to data from a variety of data sources across peers with different operating systems, databases and hardware. The proposed architecture makes use of SQL queries, web services, heterogeneous database servers and XML data transformation for the peer to peer data sharing prototype. SQL queries and web services provide a data sharing mechanism that allows both simple and flexible data access

Extending JXTA for P2P File Sharing Systems

File sharing is among the most important features of the today’s Internet-based applications. Most of such applications are server-based approaches inheriting thus the disadvantages of centralized systems. Advances in P2P systems are allowing to share huge quantities of data and files in a distributed way. In this paper, we present extensions of JXTA protocols to support file sharing in P2P systems with the aim to overcome limitations of server-mediated approaches. Our proposal is validated in practice by deploying a P2P file sharing system in a real P2P network.The empirical study revealed the benefits and drawbacks of using JXTA protocol for P2P file sharing systems.one of the most important concern

ID5.2 Roadmap for KRSM RTD

Roadmap for KRSM RTD activities.The work on this publication has been sponsored by the TENCompetence Integrated Project that is funded by the European Commission's 6th Framework Programme, priority IST/Technology Enhanced Learning. Contract 027087 [http://www.tencompetence.org

Schema matching in a peer-to-peer database system

Includes bibliographical references (p. 112-118).Peer-to-peer or P2P systems are applications that allow a network of peers to share resources in a scalable and efficient manner. My research is concerned with the use of P2P systems for sharing databases. To allow data mediation between peers' databases, schema mappings need to exist, which are mappings between semantically equivalent attributes in different peers' schemas. Mappings can either be defined manually or found semi-automatically using a technique called schema matching. However, schema matching has not been used much in dynamic environments, such as P2P networks. Therefore, this thesis investigates how to enable effective semi-automated schema matching within a P2P network

Istunnon aloitusprotokollaan pohjautuvat mobiilivertaisverkot

This work continues on my Master's Thesis work done between July 2005 and January 2006. In my Master's Thesis, we presented how a mobile peer-to-peer file-sharing application can be implemented using the Session Initiation Protocol (SIP) as the underlying signaling protocol. The main objective of this thesis is to evaluate what kind of special requirements mobile environment poses for peer-to-peer application design, and present how peer-to-peer based services can be efficiently realized in next-generation mobile networks by using SIP with some enhancements as the peer-to-peer signaling protocol. This thesis is divided into two parts. In the first part, we present different peer-to-peer architectures and search algorithms, and evaluate their suitability for mobile use. We also review some mobile peer-to-peer middleware and file-sharing applications. Then, in the second part, we present our hybrid mobile peer-to-peer architecture consisting of a Symbian based mobile client and a SIP Application Server based super-peer. Key findings of this thesis are that the mobile peer-to-peer application based on SIP signaling and hybrid peer-to-peer architecture is suitable for mobile use as it minimizes overhead in mobile nodes and allows mobile operator to have control on its users in multi-operator environment. Also, the performance of the application satisfies user requirements.Tämä työ on jatkoa diplomityölleni, joka tehtiin Heinäkuu 2005 – Tammikuu 2006 välisenä aikana. Diplomityössäni esitimme kuinka mobiilivertaisverkkosovellus voidaan toteuttaa käyttäen Session Initiation Protocol (SIP) protokollaa allaolevana signalointiprotokollana. Tämän työn päätavoite on selvittää, mitä erikoisvaatimuksia mobiiliympäristö vertaisverkkosovelluksen suunnittelulle asettaa sekä kuinka vertaisverkkopalveluita voidaan tehokkaasti toteuttaa seuraavan sukupolven mobiiliverkoissa käyttämällä laajennettua SIP protokollaa sovelluksen merkinantoprotokollana. Tämä työ on jaettu kahteen osaan. Ensimmäisessa osassa käsittelemme eri vertaisverkkoarkkitehtuureja ja hakualgoritmeja, sekä arvioimme näiden sopivuutta mobiilikäyttöön. Käymme myös läpi joitain mobiilivertaisverkkotiedostojako-ohjelmia sekä middleware-alustoja. Työn toisessa osassa esittelemme oman mobiilivertaisverkkoarkkitehtuurimme, joka koostuu Symbian mobiilisovelluksesta sekä SIP sovelluspalvelin super-peer solmusta. Tutkimuksen päälöydökset ovat seuraavat: SIP protokollaa käyttävä hybridi-vertaisverkkosovellus toimii hyvin matkapuhelinympäristössä, koska se minimoi puhelimeen kohdistuvan rasituksen ja tekee mahdolliseksi matkapuhelinoperaattorin hallita sovelluksen käyttäjiä myöskin monioperaattoriympäristössä. Tämän lisäksi ohjelmiston suorituskyky täyttää käytäjien sille asettamat vaatimukset