Distributed Proximity-Aware Peer Clustering in BitTorrent-Like Peer-to-Peer Networks

International Conference on Embedded and Ubiquitous Computing (EUC 2006), Seoul, Korea, 1-4 Aug 2006In this paper, we propose a hierarchical architecture for grouping peers into clusters in a large-scale BitTorrent-like underlying overlay network in such a way that clusters are evenly distributed and that the peers within are relatively close together. We achieve this by constructing the CBT (Clustered BitTorrent) system with two novel algorithms: a peer joining algorithm and a super-peer selection algorithm. Proximity and distribution are determined by the measurement of distances among peers. Performance evaluations demonstrate that the new architecture achieves better results than a randomly organized BitTorrent network, improving the system scalability and efficiency while retaining the robustness and incentives of original BitTorrent paradigm.Department of Computin

Consumer Value of Context Aware and Location Based Mobile Services

Context aware services have the ability to utilize information about the user’s context to adapt services to the user’s current situation and needs. In this paper we consider users’ perceptions of the added value of location awareness and presence information in mobile services. We use an experimental design, where stimuli comprising specific bundles of mobile services were presented to groups of respondents. The stimuli showed increasing, manipulated, levels of contextawareness, including location of the user and location and availability of buddies as distinct levels. Our results indicate that simply adding context aware features to mobile services does not necessarily provide added value to users, rather the contrary. The potential added value of insight in buddies’ location and availability is offset by people’s reluctance to share location information with others. Although the average perceived value overall is rather low there exists a substantial minority that does appreciate the added context aware features. High scores on constructs like product involvement, social influence and self-expressiveness characterize this group. The results also show that context aware service bundles with utilitarian elements have a higher perceived value than bundles with hedonic elements. On the basis of the different results some guidelines for designing context aware mobile services are formulated

Design of Authentication Model Preserving Intimacy and Trust in Intelligent Environments

With the recent advances in communication technologies for low-power devices, pervasive computing environments (PCE) spread as new domains beyond legacy enterprise and personal computing. The intelligent home network environment is thing which invisible device that is not shown linked mutually through network so that user may use device always is been pervasive. Smart devices are interconnected and collaborate as a global distributed system to infuse intelligence into systems and processes. This kind of environment provides various smart services and makes consequently an offer of convenient, pleasant, and blessed lives to people. However, the risk is high as long as the offer is pleasant and convenient. In such context, security is stil very fragile and there is often a violation of user privacy and service interference. For this, a special interest in ubiquitous network security is going up. Safety lies primarily in the authentication of users accessing the network. It guarantees that only legitimate users can login and access to services indoor the network. In this paper, we propose an anonymous authentication and access control scheme to secure the interaction between mobile users handling smart devices and smart services in PCEs. In an environment based on public key infrastructure (PKI) and Authentication, Authorization, and Accounting (AAA), the proposed authentication protocol combines both network authentication technique based on symmetric keys and single sign-on mechanisms. The authentication protocol is simple and secure, protects the privacy of user and aims to satisfy the security requirements

Efficent Algorithm of Energy Minimization for Heterogeneous Wireless Sensor Network

International Conference on Embedded and Ubiquitous Computing (EUC 2006), Seoul, Korea, 1-4 Aug 2006Energy and delay are critical issues for wireless sensor networks since most sensors are equipped with non-rechargeable batteries that have limited lifetime. Due to the uncertainties in execution time of some tasks, this paper models each varied execution time as a probabilistic random variable and incorporating applications’ performance requirements to solve the MAP (Mode Assignment with Probability) problem. Using probabilistic design, we propose an optimal algorithm to minimize the total energy consumption while satisfying the timing constraint with a guaranteed confidence probability. The experimental results show that our approach achieves significant energy saving than previous work. For example, our algorithm achieves an average improvement of 32.6% on total energy consumption.Department of Computin