On promoting ad-hoc collaboration among messengers

The explosion growth in the market place for handheld wireless devices has enabled new opportunities for wireless applications. Currently, handheld devices are restricted to being clients that make requests to servers and receive responses over the network. But as mobile ad-hoc networks become the trend, such devices will need to become active participants that serve requests from other devices and convey data to other devices as well. In this paper we present our vision of the future role that handheld devices will play in a mobile ad-hoc network configuration. We present this vision as part of the MESSENGER project that develops data management mechanisms for UDDI registries of Web services using mobile users and their software agents, and then describe its extension for exchanging descriptions of Web services during ad-hoc collaboration sessions. User agents are in charge of interacting with peer users over an ad-hoc network, and collaborating on feeding UDDI registries with recent content. © 2006 IEEE

Personal and groupwise broadcasting system for social event networking

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2008.Page 155 blank.Includes bibliographical references (p. 149-154).This thesis describes the design and development of a system that is aimed for personalized and group-wise broadcasts to collaboratively distribute information and to coordinate locally created events in infrastructure-free milieu. This system, called XCast, has two targets: One is to permit people to create personalized communicators, "broadcast stations" over mobile devices, for extemporaneous events or individually motivated presentations. The other is to provide people with a cognitive platform for social event awareness that informs what is happening around them and then timely coordinates the events. This system applies wireless/mobile peer-to-peer networking technologies, such as 802.11 ad-hoc and mesh networking. To achieve the targets, in the thesis, we focus on newly designing architecture of the cognitive platform and then developing a robust and agile protocol which makes it possible for the platform to reliably work in wireless ad-hoc/mesh networks. The former work is to build a group of broadcast stations into a distributed crystal-gazing system to be aware seasonably of what is going on in our surroundings. With respect to the latter, we propose a distributed protocol, dubbed "Broadcast Resource Schedule Protocol (BRSP)." It has broadcast operations more reliable and scalable in wireless ad-hoc/mesh networks via synchronization and neighbor knowledge schemes. In the end, the BRSP evolves a wireless peer-to-peer network into a cognitive network to support the platform. This system offers a riper breeding ground for creation of a platform for social event networking and of cooperative media for a local community. The value of this is in considering community networks that are matrices of social collaboration, rather than point connections, as well as sources of novel civic media initiated by grassroots.by Sung-Hyuck Lee.S.M

A Resource Intensive Traffic-Aware Scheme for Cluster-based Energy Conservation in Wireless Devices

Wireless traffic that is destined for a certain device in a network, can be exploited in order to minimize the availability and delay trade-offs, and mitigate the Energy consumption. The Energy Conservation (EC) mechanism can be node-centric by considering the traversed nodal traffic in order to prolong the network lifetime. This work describes a quantitative traffic-based approach where a clustered Sleep-Proxy mechanism takes place in order to enable each node to sleep according to the time duration of the active traffic that each node expects and experiences. Sleep-proxies within the clusters are created according to pairwise active-time comparison, where each node expects during the active periods, a requested traffic. For resource availability and recovery purposes, the caching mechanism takes place in case where the node for which the traffic is destined is not available. The proposed scheme uses Role-based nodes which are assigned to manipulate the traffic in a cluster, through the time-oriented backward difference traffic evaluation scheme. Simulation study is carried out for the proposed backward estimation scheme and the effectiveness of the end-to-end EC mechanism taking into account a number of metrics and measures for the effects while incrementing the sleep time duration under the proposed framework. Comparative simulation results show that the proposed scheme could be applied to infrastructure-less systems, providing energy-efficient resource exchange with significant minimization in the power consumption of each device.Comment: 6 pages, 8 figures, To appear in the proceedings of IEEE 14th International Conference on High Performance Computing and Communications (HPCC-2012) of the Third International Workshop on Wireless Networks and Multimedia (WNM-2012), 25-27 June 2012, Liverpool, U

Analysis of a Reputation System for Mobile Ad-Hoc Networks with Liars

The application of decentralized reputation systems is a promising approach to ensure cooperation and fairness, as well as to address random failures and malicious attacks in Mobile Ad-Hoc Networks. However, they are potentially vulnerable to liars. With our work, we provide a first step to analyzing robustness of a reputation system based on a deviation test. Using a mean-field approach to our stochastic process model, we show that liars have no impact unless their number exceeds a certain threshold (phase transition). We give precise formulae for the critical values and thus provide guidelines for an optimal choice of parameters.Comment: 17 pages, 6 figure

GRIDKIT: Pluggable overlay networks for Grid computing

A `second generation' approach to the provision of Grid middleware is now emerging which is built on service-oriented architecture and web services standards and technologies. However, advanced Grid applications have significant demands that are not addressed by present-day web services platforms. As one prime example, current platforms do not support the rich diversity of communication `interaction types' that are demanded by advanced applications (e.g. publish-subscribe, media streaming, peer-to-peer interaction). In the paper we describe the Gridkit middleware which augments the basic service-oriented architecture to address this particular deficiency. We particularly focus on the communications infrastructure support required to support multiple interaction types in a unified, principled and extensible manner-which we present in terms of the novel concept of pluggable overlay networks

Security in Wireless Sensor Networks: Issues and Challenges

Wireless Sensor Network (WSN) is an emerging technology that shows great promise for various futuristic applications both for mass public and military. The sensing technology combined with processing power and wireless communication makes it lucrative for being exploited in abundance in future. The inclusion of wireless communication technology also incurs various types of security threats. The intent of this paper is to investigate the security related issues and challenges in wireless sensor networks. We identify the security threats, review proposed security mechanisms for wireless sensor networks. We also discuss the holistic view of security for ensuring layered and robust security in wireless sensor networks.Comment: 6 page