Marcin Matuszewski

A Distributed IP Multimedia Subsystem (IMS)

This document presents the architecture of a distributed IP Multimedia Subsystem (IMS). The architecture distributes network functional elements in Distributed Hash Tables (DHT) overlay network. This work focuses on distributing the SIP proxies, such as the Serving-Call/Session Control Function (S-CSCF) and the Interrogating-Call/Session Control Function, as well as the Home Subscriber server (HSS), and up to some degree, presence servers. A combined DHT overlay network is also proposed. Distribution of the network functional elements in a DHT fashion leads to increased robustness of IMS network elements. Besides the self-organizing overlay network offers a significant savings in OPEX.

Content sharing in mobile P2P networks: myth or reality?

Peer-to-Peer (P2P) networks have altered the landscape of content distribution in the internet. P2P content sharing is getting more and more popular, especially among the young people who have grown up in the Napster era. The recent developments in mobile technology have also opened room for deployment of novel P2P content sharing services in mobile networks. In this paper, we propose a new architecture of a Mobile Peer-to-Peer (MP2P) resource sharing system. The system transports P2P control traffic in Session Initiation Protocol (SIP) messages. It can be implemented in the IP Multimedia Subsystem (IMS), making it interoperable and compliant with modern third generation cellular networks. In order to verify the proposed architecture, we implemented a MP2P content sharing system. The results of the conducted trial are encouraging.

Mobile peer-to-peer content sharing application

The demo presents a novel architecture of Mobile Peer-to-Peer (MP2P) content sharing services in cellular networks. The proposed solution is based on Session Initiation Protocol (SIP) that is part of the IP Multimedia Subsystem (IMS) in third-generation cellular networks. The concept has been implemented in C++ on the Symbian Series 60 platform. The conducted trial showed the feasibility of proposed approach and opens new room for development of scalable services in the mobile environment.

Resource Sharing and Discovery on Top of IMS

This paper presents the architecture and the signaling flows of a multi-service overlay network implemented over the IP Multimedia Subsystem (IMS). The overlay network uses the concept of SIP-based Peer-to-peer (P2P) for providing resource sharing services, such as photograph exchange, allowing the distribution of resources across an overlay network formed for that purpose. The SIP P2P overlay network forms a cost efficient platform for providing innovative mobile services. Using the presented platform, fixed and mobile operators can provide valuable services utilizing the strengths of the IMS such as sophisticated charging, control, security and authentication mechanisms.

Peer-to-Peer Knowledge Sharing in the Mobile Environment

This paper discusses knowledge sharing in the corporate environment. It studies different barriers for knowledge sharing as well as incentive programs that are aiming to motivate employees to engage in the knowledge sharing activity. Finally it presents a new peer-to-peer (P2P) knowledge sharing paradigm and the architecture of a mobile peer-to-peer knowledge sharing system. The proposed P2P knowledge sharing paradigm addresses the major issues of mobile communication as well as human aspects of social interactions. It supports communities and utilizes strengths of peer-to-peer social networks. The system implementation proves technical feasibility of the proposed approach.

Social Distributed Hash Table

This paper presents an architecture called social distributed hash table (SDHT) that combines strengths of distributed hash table (DHT) algorithms and social networks making mobile search fast and context oriented. The paper presents possible implementations of the proposed architecture in the IP multimedia subsystem (IMS) and as a standalone SIP based system. The architecture forms a cost efficient platform for providing innovative mobile services that take advantage of social context of human communication. The architecture can be used to deploy a global virtual mobile network by placing SDHT nodes in different geographical regions. The paper also presents a content sharing inside community service.

Contacter: An Enhanced Contact Application for Easy Update and Recovery of Contacts Using the Session Initiation Protocol (SIP)

This paper presents a peer-to-peer (P2P) application that extends functionality of Personal Information Manager (PIM) software installed in end user devices such as mobile phones. The application facilitates end-to-end connectivity by allowing devices to automatically request contact information from and update contact information stored in other devices. Utilizing automatic update of contact information the application also provides a method for recovery of lost contact information. The application utilizes the session initiation protocol (SIP) for establishing sessions between peer nodes making the system interoperable with IP multimedia subsystem (IMS) in cellular and fixed networks. The application can be used to support community services.

DHT Performance for Peer-to-Peer SIP - A Mobile Phone Perspective

In this paper we investigate the DHT performance for Peer-to-peer SIP. We analyze performance from the mobile phone perspective. This angle brings battery consumption and efficient use of the limited resources of the mobile devices to the focus. We develop an analytical model of Kademlia DHT performance and use it to analyze a number of different strategies to use peer-to-peer SIP with mobile devices. These analyses include studying a model where all devices participate in the DHT and contrasting that with a model where only a subset of devices forms the DHT. Our analysis shows that in a one million user P2PSIP network, at least 30% of the mobile nodes should participate in operating the DHT to remain energy-efficient.