Improving the Performance of Mobile Ad Hoc Network Using a Combined Credit Risk and Collaborative Watchdog Method

In mobile ad hoc networks nodes can move freely and link node failures occur frequently This leads to frequent network partitions which may significantly degrade the performance of data access in ad hoc networks When the network partition occurs mobile nodes in one network are not able to access data hosted by nodes in other networks In mobile ad hoc network some nodes may selfishly decide only to cooperate partially or not at all with other nodes These selfish nodes could then reduce the overall data accessibility in the network In this work the impact of selfish nodes in a mobile ad hoc network from the perspective of replica allocation is examined We term this selfish replica allocation A combined credit risk method collaborative watchdog is proposed to detect the selfish node and also apply the SCF tree based replica allocation method to handle the selfish replica allocation appropriately The proposed method improves the data accessibility reduces communication cost and average query delay and also to reduce the detection time and to improve the accuracy of watchdogs in the collaborative metho

An Incentive Mechanism for Cooperative Data Replication in MANETs - a Game Theoretical Approach

Wireless ad hoc networks have seen a great deal of attention in the past years, especially in cases where no infrastructure is available. The main goal in these networks is to provide good data accessibility for participants. Because of the wireless nodes' continuous movement, network partitioning occurs very often. In order to subside the negative effects of this partitioning and improve data accessibility and reliability, data is replicated in nodes other than the original owner of data. This duplication costs in terms of nodes' storage space and energy. Hence, autonomous nodes may behave selfishly in this cooperative process and do not replicate data. This kind of phenomenon is referred to as a strategic situation and is best modeled and analyzed using the game theory concept. In order to address this problem we propose a game theory data replication scheme by using the repeated game concept and prove that it is in the nodes' best interest to cooperate fully in the replication process if our mechanism is used

An Incentive Mechanism for Cooperative Data Replication in MANETs - A Game Theoretical Approach

Wireless ad hoc networks have seen a great deal of attention in the past years, especially in cases where no infrastructure is available. The main goal in these networks is to provide good data accessibility for participants. Because of the wireless nodes’ continuous movement, network partitioning occurs very often. In order to subside the negative effects of this partitioning and improve data accessibility and reliability, data is replicated in nodes other than the original owner of data. This duplication costs in terms of nodes’ storage space and energy. Hence, autonomous nodes may behave selfishly in this cooperative process and do not replicate data. This kind of phenomenon is referred to as a strategic situation and is best modeled and analyzed using the game theory concept. In order to address this problem we propose a game theory data replication scheme by using the repeated game concept and prove that it is in the nodes’ best interest to cooperate fully in the replication process if our mechanism is used

Social-aware hybrid mobile offloading

Mobile offloading is a promising technique to aid the constrained resources of a mobile device. By offloading a computational task, a device can save energy and increase the performance of the mobile applications. Unfortunately, in existing offloading systems, the opportunistic moments to offload a task are often sporadic and short-lived. We overcome this problem by proposing a social-aware hybrid offloading system (HyMobi), which increases the spectrum of offloading opportunities. As a mobile device is always co- located to at least one source of network infrastructure throughout of the day, by merging cloudlet, device-to-device and remote cloud offloading, we increase the availability of offloading support. Integrating these systems is not trivial. In order to keep such coupling, a strong social catalyst is required to foster user's participation and collaboration. Thus, we equip our system with an incentive mechanism based on credit and reputation, which exploits users' social aspects to create offload communities. We evaluate our system under controlled and in-the-wild scenarios. With credit, it is possible for a device to create opportunistic moments based on user's present need. As a result, we extended the widely used opportunistic model with a long-term perspective that significantly improves the offloading process and encourages unsupervised offloading adoption in the wild

Mobility-aware fog computing in dynamic networks with mobile nodes: A survey

Fog computing is an evolving paradigm that addresses the latency-oriented performance and spatio-temporal issues of the cloud services by providing an extension to the cloud computing and storage services in the vicinity of the service requester. In dynamic networks, where both the mobile fog nodes and the end users exhibit time-varying characteristics, including dynamic network topology changes, there is a need of mobility-aware fog computing, which is very challenging due to various dynamisms, and yet systematically uncovered. This paper presents a comprehensive survey on the fog computing compliant with the OpenFog (IEEE 1934) standardised concept, where the mobility of fog nodes constitutes an integral part. A review of the state-of-the-art research in fog computing implemented with mobile nodes is conducted. The review includes the identification of several models of fog computing concept established on the principles of opportunistic networking, social communities, temporal networks, and vehicular ad-hoc networks. Relevant to these models, the contributing research studies are critically examined to provide an insight into the open issues and future research directions in mobile fog computing research

Social distributed content caching in federated residential networks

This work addresses the need for content sharing and backup in household equipped with a home gateway that stores, tags and manages the data collected by the home users. Our solution leverages the interaction between remote gateways in a social way, i.e., by exploiting the users' social networking information, so that caching recipients are those gateways whose users are most likely to be interested in accessing the shared content. We formulate this problem as a Budgeted Maximum Coverage (BMC) problem and we numerically compute the optimal content caching solution. We then propose a low-complexity, distributed heuristic algorithm and use simulation in a synthetic social network scenario to show that the final content placement among "friendly" gateways well approximates the optimal solution under different network setting

Cooperative Data Backup for Mobile Devices

Les dispositifs informatiques mobiles tels que les ordinateurs portables, assistants personnels et téléphones portables sont de plus en plus utilisés. Cependant, bien qu'ils soient utilisés dans des contextes où ils sont sujets à des endommagements, à la perte, voire au vol, peu de mécanismes permettent d'éviter la perte des données qui y sont stockées. Dans cette thèse, nous proposons un service de sauvegarde de données coopératif pour répondre à ce problème. Cette approche tire parti de communications spontanées entre de tels dispositifs, chaque dispositif stockant une partie des données des dispositifs rencontrés. Une étude analytique des gains de cette approche en termes de sûreté de fonctionnement est proposée. Nous étudions également des mécanismes de stockage réparti adaptés. Les problèmes de coopération entre individus mutuellement suspicieux sont également abordés. Enfin, nous décrivons notre mise en oeuvre du service de sauvegarde coopérative. ABSTRACT : Mobile devices such as laptops, PDAs and cell phones are increasingly relied on but are used in contexts that put them at risk of physical damage, loss or theft. However, few mechanisms are available to reduce the risk of losing the data stored on these devices. In this dissertation, we try to address this concern by designing a cooperative backup service for mobile devices. The service leverages encounters and spontaneous interactions among participating devices, such that each device stores data on behalf of other devices. We first provide an analytical evaluation of the dependability gains of the proposed service. Distributed storage mechanisms are explored and evaluated. Security concerns arising from thecooperation among mutually suspicious principals are identified, and core mechanisms are proposed to allow them to be addressed. Finally, we present our prototype implementation of the cooperative backup servic