Distributed Dynamic Host Configuration Protocol (D2HCP)

Mobile Ad Hoc Networks (MANETs) are multihop wireless networks of mobile nodes without any fixed or preexisting infrastructure. The topology of these networks can change randomly due to the unpredictable mobility of nodes and their propagation characteristics. In most networks, including MANETs, each node needs a unique identifier to communicate. This work presents a distributed protocol for dynamic node IP address assignment in MANETs. Nodes of a MANET synchronize from time to time to maintain a record of IP address assignments in the entire network and detect any IP address leaks. The proposed stateful autoconfiguration scheme uses the OLSR proactive routing protocol for synchronization and guarantees unique IP addresses under a variety of network conditions, including message losses and network partitioning. Simulation results show that the protocol incurs low latency and communication overhead for IP address assignment

Supporting Collaboration in Mobile Environments

Continued rapid improvements in the hardware capabilities of mobile computing devices is driving a parallel need for a paradigm shift in software design for such devices with the aim of ushering in new classes of software applications for devices of the future. One such class of software application is collaborative applications that seem to reduce the burden and overhead of collaborations on human users by providing automated computational support for the more mundane and mechanical aspects of a cooperative effort. This dissertation addresses the research and software engineering questions associated with building a workflow-based collaboration system that can operate across mobile ad hoc networks, the most dynamic type of mobile networks that can function without dependence on any fixed external resources. While workflow management systems have been implemented for stable wired networks, the transition to a mobile network required the development of a knowledge management system for improving the predictability of the network topology, a mobility-aware specification language to specify workflows, and its accompanying algorithms that help automate key pieces of the software. In addition to details of the formulation, design, and implementation of the various algorithms and software components. this dissertation also describes the construction of a custom mobile workflow simulator that can be used to conduct simulation experiments that verify the effectiveness of the approaches presented in this document and beyond. Also presented are empirical results obtained using this simulator that show the effectiveness of the described approaches

Building an IP-based community wireless mesh network: Assessment

Wireless mesh networks are experiencing rapid progress and inspiring numerous applica tions in different scenarios, due to features such as autoconfiguration, self healing, connec tivity coverage extension and support for dynamic topologies. These particular characteristics make wireless mesh networks an appropriate architectural basis for the design of easy to deploy community or neighbourhood networks. One of the main chal lenges in building a community network using mesh networks is the minimisation of user intervention in the IP address configuration of the network nodes. In this paper we first consider the process of building an IP based mesh network using typical residential rou ters, exploring the options for the configuration of their wireless interfaces. Then we focus on IP address autoconfiguration, identifying the specific requirements for community mesh networks and analysing the applicability of existing solutions. As a result of that analysis, we select PACMAN, an efficient distributed address autoconfiguration mechanism origi nally designed for ad hoc networks, and we perform an experimental study using off the shelf routers and assuming worst case scenarios analysing its behaviour as an IP address autoconfiguration mechanism for community wireless mesh networks. The results of the conducted assessment show that PACMAN meets all the identified requirements of the community scenario.European Community´s Seventh Framework ProgramPublicad

Collaboration Enforcement In Mobile Ad Hoc Networks

Mobile Ad hoc NETworks (MANETs) have attracted great research interest in recent years. Among many issues, lack of motivation for participating nodes to collaborate forms a major obstacle to the adoption of MANETs. Many contemporary collaboration enforcement techniques employ reputation mechanisms for nodes to avoid and penalize malicious participants. Reputation information is propagated among participants and updated based on complicated trust relationships to thwart false accusation of benign nodes. The aforementioned strategy suffers from low scalability and is likely to be exploited by adversaries. To address these problems, we first propose a finite state model. With this technique, no reputation information is propagated in the network and malicious nodes cannot cause false penalty to benign hosts. Misbehaving node detection is performed on-demand; and malicious node punishment and avoidance are accomplished by only maintaining reputation information within neighboring nodes. This scheme, however, requires that each node equip with a tamper-proof hardware. In the second technique, no such restriction applies. Participating nodes classify their one-hop neighbors through direct observation and misbehaving nodes are penalized within their localities. Data packets are dynamically rerouted to circumvent selfish nodes. In both schemes, overall network performance is greatly enhanced. Our approach significantly simplifies the collaboration enforcement process, incurs low overhead, and is robust against various malicious behaviors. Simulation results based on different system configurations indicate that the proposed technique can significantly improve network performance with very low communication cost

Eighth Workshop and Tutorial on Practical Use of Coloured Petri Nets and the CPN Tools, Aarhus, Denmark, October 22-24, 2007

This booklet contains the proceedings of the Eighth Workshop on Practical Use of Coloured Petri Nets and the CPN Tools, October 22-24, 2007. The workshop is organised by the CPN group at the Department of Computer Science, University of Aarhus, Denmark. The papers are also available in electronic form via the web pages: http://www.daimi.au.dk/CPnets/workshop0

Mobile Ad Hoc Networks

Guiding readers through the basics of these rapidly emerging networks to more advanced concepts and future expectations, Mobile Ad hoc Networks: Current Status and Future Trends identifies and examines the most pressing research issues in Mobile Ad hoc Networks (MANETs). Containing the contributions of leading researchers, industry professionals, and academics, this forward-looking reference provides an authoritative perspective of the state of the art in MANETs. The book includes surveys of recent publications that investigate key areas of interest such as limited resources and the mobility of mobile nodes. It considers routing, multicast, energy, security, channel assignment, and ensuring quality of service. Also suitable as a text for graduate students, the book is organized into three sections: Fundamentals of MANET Modeling and Simulation—Describes how MANETs operate and perform through simulations and models Communication Protocols of MANETs—Presents cutting-edge research on key issues, including MAC layer issues and routing in high mobility Future Networks Inspired By MANETs—Tackles open research issues and emerging trends Illustrating the role MANETs are likely to play in future networks, this book supplies the foundation and insight you will need to make your own contributions to the field. It includes coverage of routing protocols, modeling and simulations tools, intelligent optimization techniques to multicriteria routing, security issues in FHAMIPv6, connecting moving smart objects to the Internet, underwater sensor networks, wireless mesh network architecture and protocols, adaptive routing provision using Bayesian inference, and adaptive flow control in transport layer using genetic algorithms