Cross-layer Peer-to-Peer Computing in Mobile Ad Hoc Networks

The future information society is expected to rely heavily on wireless technology. Mobile access to the Internet is steadily gaining ground, and could easily end up exceeding the number of connections from the fixed infrastructure. Picking just one example, ad hoc networking is a new paradigm of wireless communication for mobile devices. Initially, ad hoc networking targeted at military applications as well as stretching the access to the Internet beyond one wireless hop. As a matter of fact, it is now expected to be employed in a variety of civilian applications. For this reason, the issue of how to make these systems working efficiently keeps the ad hoc research community active on topics ranging from wireless technologies to networking and application systems. In contrast to traditional wire-line and wireless networks, ad hoc networks are expected to operate in an environment in which some or all the nodes are mobile, and might suddenly disappear from, or show up in, the network. The lack of any centralized point, leads to the necessity of distributing application services and responsibilities to all available nodes in the network, making the task of developing and deploying application a hard task, and highlighting the necessity of suitable middleware platforms. This thesis studies the properties and performance of peer-to-peer overlay management algorithms, employing them as communication layers in data sharing oriented middleware platforms. The work primarily develops from the observation that efficient overlays have to be aware of the physical network topology, in order to reduce (or avoid) negative impacts of application layer traffic on the network functioning. We argue that cross-layer cooperation between overlay management algorithms and the underlying layer-3 status and protocols, represents a viable alternative to engineer effective decentralized communication layers, or eventually re-engineer existing ones to foster the interconnection of ad hoc networks with Internet infrastructures. The presented approach is twofold. Firstly, we present an innovative network stack component that supports, at an OS level, the realization of cross-layer protocol interactions. Secondly, we exploit cross-layering to optimize overlay management algorithms in unstructured, structured, and publish/subscribe platforms

An Analysis of Node/Peer Discovery Approach and Routing Algorithms in Mobile & Traditional Peer-to-Peer Networks

Mobile devices are becoming an increasingly indispensable part of people’s everyday life, in the form of mobile phones, PDAs and laptop computers to communicate or share data between them. Centralized client-server networks are being transformed to distributed peer-to-peer networks. Lessons learned from fixed networks have been applied in cellular network. So, there are many challenges faced by traditional and mobile peer-to-peer networks therefore, in this study we examine a comparative analysis of node/peer discovery approach and routing algorithms employed in both traditional and mobile peer-to-peer networks. A qualitative methodology approach was used for data sources. Documents related to node/peer discovery approach and routing algorithms were studied. A comparative method and content analysis were used to analyze the data collected. Findings of the study indicated that there are two clear differences in the aspects of neighboring node/peer discovery approach beside the similarities. The study also showed another differences and similarities in the aspect of routing algorithms. This thesis hopes to offer all necessary useful tips of the divergence on these two aspects and thus to make a contribution allowing researchers to know such divergence

Trust Based Scheme for QoS Assurance in Mobile Ad-Hoc Networks

A mobile ad-hoc network (MANET) is a peer-to-peer wireless network where nodes can communicate with each other without the use of infrastructure such as access points or base stations. These networks are self-configuring, capable of self-directed operation and hastily deployable. Nodes cooperate to provide connectivity, operates without centralized administration. Nodes are itinerant, topology can be very dynamic and nodes must be able to relay traffic since communicating nodes might be out of range. The dynamic nature of MANET makes network open to attacks and unreliability. Routing is always the most significant part for any networks. Each node should not only work for itself, but should be cooperative with other nodes. Node misbehaviour due to selfish or malicious intention could significantly degrade the performance of MANET. The Qos parameters like PDR, throughput and delay are affected directly due to such misbehaving nodes. We focus on trust management framework, which is intended to cope with misbehaviour problem of node and increase the performance of MANETs. A trust-based system can be used to track this misbehaving of nodes, spot them and isolate them from routing and provide reliability. In this paper a Trust Based Reliable AODV [TBRAODV] protocol is presented which implements a trust value for each node. For every node trust value is calculated and based trust value nodes are allowed to participate in routing or else identified to become a misbehaving node. This enhances reliability in AODV routing and results in increase of PDR, decrease in delay and throughput is maintained. This work is implemented and simulated on NS-2. Based on simulation results, the proposed protocol provides more consistent and reliable data transfer compared with general AODV, if there are misbehaving nodes in the MANE

Reliable communication across ad hoc networks

This paper presents a fully decentralised peer-topeer voice communication tool intended for use across mobile ad hoc networks (MANET) by distributed groups who desired collaboration. We examined the synergy between MANETs and peer-to-peer virtual overlay networks which allowed the creation of ad hoc applications. One style of communication considered suitable for task oriented distributed group collaboration was push-to-talk. This research was focused on providing a push-to-talk communication platform suitable for deployment across MANETs. The research methodology employed was a proof of concept approach within a classical experimental computer science paradigm. We developed a prototype which used JXTA, a peer-to-peer virtual overlay network, to provide push-to-talk functionality across MANETs. Guaranteed delivery of messages was provided via a peer-to-peer voicemail delivery system. While the system did what intended we show that JXTA had a problem with the efficient delivery of voice samples.Telkom, Cisco, THRI

File management in a mobile DHT-based P2P environment

The emergence of mobile P2P systems is largely due to the evolution of mobile devices into powerful information processing units. The relatively structured context that results from the mapping of mobile patterns of behaviour onto P2P models is however constrained by the vulnerabilities of P2P networks and the inherent limitations of mobile devices. Whilst the implementation of P2P models gives rise to security and reliability issues, the deployment of mobile devices is subject to efficiency constraints. This paper presents the development and deployment of a mobile P2P system based on distributed hash tables (DHT). The secure, reliable and efficient dispersal of files is taken as an application. Reliability was addressed by providing two methods for file dispersal: replication and erasure coding. Security constraints were catered for by incorporating an authentication mechanism and three encryption schemes. Lightweight versions of various algorithms were selected in order to attend to efficiency requirements

A novel peer-to-peer personalized advertising framework using ad hoc wireless communication

The proliferation of mobile devices and pervasiveness of wireless technology have provided a new environment for mobile commerce (M-Commerce).In this environment, mobile advertising will be playing an important role in mobile commerce marketing. Generally, mobile advertising can be defined as advertising a product advertisement or a service advertisement to the mobile users via wireless network.This paper discusses some issues in mobile advertising and proposes a framework for mobile advertising using peer-to-peer ad hoc wireless communications

Context-Aware Group Communication in Mobile Ad-Hoc Networks

Abstract. The widespread availability of both fixed and wireless network con-nectivity and the growing market of portable devices are enabling anytime and anywhere impromptu collaboration. The emergence of Mobile Ad-Hoc Net-works (MANET) further opens up new possibilities for the provisioning of ad-vanced collaborative services, such as civil protection, e-care, and troop car management. However, the design and the deployment of collaborative appli-cations in MANET scenarios raises new group management challenges. In par-ticular, MANET characteristics, e.g., unpredictable and frequent mobility of us-ers/devices, intermittent device connectivity, continuous variations of network topology, make it impossible any a-priori knowledge about group members availability and ask for novel solutions to handle properly the communication about group members. The paper proposes a context-aware communication model to govern communication on the basis of the characteristics of the com-municating parties, such as their location and their profiling information. The model provides communication patterns with different semantics to address both point-to-point and point-to-multipoint communication needs. The paper shows the implementation of the proposed model in the AGAPE framework for the design, deployment, and support of collaborative applications in MANET environments and presents the functioning of the AGAPE communication sup-port in the context of a civil protection application scenario.

Priority Based Routing for Mobile Peer-To-Peer Communications

In a Mobile Peer-to-Peer (MP2P) network, mobile nodes share their resources among one another in a mobile wireless environment. Communication among nodes in MP2P network has become an important area for research due to the significance of its applications. The success of these MP2P applications depends on the number of users in the network, popularity of services offered, quick response and faster access to services. Some services offered could be more popular than others and some peers may contribute more to the network by catering to more requests compared to other peers. In priority based routing mechanism, there is an increase in the priority of a peer with the increase in the number of times it provides services to other peers. The priority of a shared service also increases as the number of requests for that service increases. Also, the mechanism of priority based mobile peer-to-peer routing provides higher priority for traffic destined to high contributing peers and the traffic of popular services, during routing. This would provide high contributing peers quicker response and faster access to services. Hence, this mechanism motivates more users to join the MP2P network and contribute more to the network

Analysis and Design of Mobile Collaborative Applications Using Contextual Elements

Collaborative mobile applications support users on the move in order to perform a collaborative task. One of the challenges when designing such applications is to consider the context where they will execute. Contextualized applications are easy to adopt by the users; unfortunately the design of contextualized tools is not evident. This paper presents a framework of contextual elements to be considered during the conception, analysis and design phases of a mobile collaborative application. This framework supports developers to identify non-functional requirements and part of the architectural design in order to get contextualized applications. The use of this framework is complementary to any structured software process. A framework use example is also presented as an illustration of its applicability