Ubiquitous computing with service adaptation using peer-to-peer communication framework

Author(s):  
T. Iwao ◽  
S. Amamiya ◽  
Guoqiang Zhong ◽  
M. Amamiya
Author(s):  
Takumi Miyoshi ◽  
Yusuke Shimomura ◽  
Olivier Fourmaux

This paper proposes a novel peer-to-peer communication framework to implement geographical location oriented networks, called G-LocON. Location-based services have been gaining in popularity, as proven by ridesharing and mobile games. Although these services have to construct geolocation oriented networks based on their users’ geographical locations, they completely rely on client/server models to communicate with neighboring terminals. G-LocON provides geolocation oriented device-to-device communication only with the current wireless technologies, such as LTE and Wi-Fi, cooperating with the global positioning system and peer-to-peer overlay networking. G-LocON will serve as a type of a mobile ad-hoc network in which devices located within the focusing area are capable of communicating directly. We developed a primitive Android application to implement the GLocON framework. Evaluation of the solution’s performance has verified the usefulness of the proposed system that offers an admissive transmission delay. Moreover, to confirm the application-related potential of the G-LocON framework, we also show a practical map software in which all neighboring mobile devices present in the focusing area are displayed.


Author(s):  
Xianghan Zheng ◽  
Vladimir Oleshchuk

Today, Peer-to-Peer SIP based communication systems have attracted much attention from both the academia and industry. The decentralized nature of P2P might provide the distributed peer-to-peer communication system without help of the traditional SIP server. However, the decentralization features come to the cost of the reduced manageability and create new concerns. Until now, the main focus of research was on the availability of the network and systems, while few attempts are put on protecting privacy. In this chapter, we investigate on P2PSIP security issues and introduce two enhancement solutions: central based security and distributed trust security, both of which have their own advantages and disadvantages. After that, we study appropriate combination of these two approaches to get optimized protection. Our design is independent of the DHT (Distributed Hash Table) overlay technology. We take the Chord overlay as the example, and then, analyze the system in several aspects: security & privacy, number-of the hops, message flows, etc.


Author(s):  
Fabian Stäber ◽  
Gerald Kunzmann ◽  
Jörg P. Müller

Decentralized peer-to-peer systems fit well as the underlying infrastructure for IP-telephony, as they provide the scalability for a large number of participants, and are able to handle the limited storage and bandwidth capabilities on the clients. We studied a commercial peer-to-peer-based decentralized communication platform supporting video communication, voice communication, instant messaging, et cetera. One of the requirements of the communication platform is the implementation of a user directory, allowing users to search for other participants. In this chapter, we present the Extended Prefix Hash Tree algorithm that enables the implementation of a user directory on top of the peer-to-peer communication platform in a fully decentralized way. We evaluate the performance of the algorithm with a real-world phone book. The results can be transferred to other scenarios where support for range queries is needed in combination with the decentralization, self-organization, and resilience of an underlying peer-to-peer infrastructure.


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