345 research outputs found

    Enhancing Cooperation in MANET Using the Backbone Group Model (An Application of Maximum Coverage Problem)

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    AbstractMANET is a cooperative network in which every node is responsible for routing and forwarding as a result consumes more battery power and bandwidth. In order to save itself in terms of battery power and bandwidth noncooperation is genuine. Cooperation can be enhanced on the basis of reduction in resource consumption by involving a limited number of nodes in routing activities rather than all. To get accurate selection of nodes to define a backbone several works have been proposed in the literature. These works define a backbone with impractical assumptions that is not feasible for MANET. In this paper we have presented the Backbone Group (BG) model, which involve the minimum number of nodes called BG in routing activities instead of all. A BG is a minimal set of nodes that efficiently connects the network. We have divided a MANET in terms of the single hop neighborhood called locality group (LG). In a LG we have a cluster head (CH), a set of regular nodes (RNs) and one or more border nodes (BNs). The CHs are responsible for the creation and management of LG and BG. The CHs use a BG for a threshold time then switches to another BG, to involve all nodes in network participation. The proposed model shows its effectiveness in terms of reduction in routing overhead up to a ratio (n2: n2/k) where k is the number of LGs

    Ad hoc network security and modeling with stochastic petri nets

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    Advances in wireless technology and portable computing along with demands for high user mobility have provided a major promotion toward the development of ad hoc networks. These networks feature dynamic topology, self-organization, limited bandwidth and battery power of a node. Unlike the existing commercial wireless systems and fixed infrastructure networks, they do not rely on specialized routers for path discovery and traffic routing. Security is an important issue in such networks. Typically, mobile nodes are significantly more susceptible to physical attacks than their wired counterparts. This research intends to investigate the ad hoc network routing security by proposing a performance enhanced Secure ad hoc On-demand Routing protocol (SOR). Specifically, it presents a method to embed Security Level into ad hoc on-demand routing protocols using node-disjoint multipath, and to use maximum hopcount to restrict the number of routing packets in a specific area. The proposed scheme enables the use of security as a marked factor to improve the relevance of the routes discovered by ad hoc routing protocols. It provides customizable security to the flow of routing protocol messages. In general, SOR offers an alternative way to implement security in on-demand routing protocols. Ad hoc network is too complex to allow analytical study for explicit performance expressions. This research presents a Stochastic Petri net-based approach to modeling and analysis of mobile ad hoc network. This work illustrates how this model is built as a scalable model and used to exploit the characteristics of the networks. The proposed scheme is a powerful analytical model that can be used to derive network performance much more easily than a simulation-based approach. Furthermore, the proposed model is extended to study the performance of ad hoc network security by adding multipath selection and security measurement parameters. This research gives a quantificational measurement to analyze the performance of a modified SPN model under the effect of multipath and attack of a hypothetical compromised node

    Sensor function virtualization to support distributed intelligence in the internet of things

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    It is estimated that-by 2020-billion devices will be connected to the Internet. This number not only includes TVs, PCs, tablets and smartphones, but also billions of embedded sensors that will make up the "Internet of Things" and enable a whole new range of intelligent services in domains such as manufacturing, health, smart homes, logistics, etc. To some extent, intelligence such as data processing or access control can be placed on the devices themselves. Alternatively, functionalities can be outsourced to the cloud. In reality, there is no single solution that fits all needs. Cooperation between devices, intermediate infrastructures (local networks, access networks, global networks) and/or cloud systems is needed in order to optimally support IoT communication and IoT applications. Through distributed intelligence the right communication and processing functionality will be available at the right place. The first part of this paper motivates the need for such distributed intelligence based on shortcomings in typical IoT systems. The second part focuses on the concept of sensor function virtualization, a potential enabler for distributed intelligence, and presents solutions on how to realize it

    Mobile Ad-Hoc Networks

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    Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: vehicular ad-hoc networks, security and caching, TCP in ad-hoc networks and emerging applications. It is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks

    Constructing Dynamic Ad-hoc Emergency Networks using Software-Defined Wireless Mesh Networks

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    Natural disasters and other emergency situations have the potential to destroy a whole network infrastructure needed for communication critical to emergency rescue, evacuation, and initial rehabilitation. Hence, the research community has begun to focus attention on rapid network reconstruction in such emergencies; however, research has tried to create or improve emergency response systems using traditional radio and satellite communications, which face high operation costs and frequent disruptions. This thesis proposes a centralized monitoring and control system to reconstruct ad-hoc networks in emergencies by using software-defined wireless mesh networks (SDWMN). The proposed framework utilizes wireless mesh networks and software-defined networking to provide real-time network monitoring services to restore Internet access in a targeted disaster zone. It dispatches mobile devices including unmanned aerial vehicles and self-driving cars to the most efficient location aggregation to recover impaired network connections by using a new GPS position finder (GPS-PF) algorithm. The algorithm is based on density-based spatial clustering that calculates the best position to deploy one of the mobile devices. The proposed system is evaluated using the common open research emulator to demonstrate its efficiency and high accessibility in emergency situations. The results obtained from the evaluation show that the performance of the emergency communication system is improved considerably with the incorporation of the framework

    Ad-hoc wireless networking for supporting on-site communication

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    Ad-hoc networks are self-organized wireless networks. They have the potential to be widely used in emergency salvation, construction sites, and military fields. However, the research about the efficient usage of ad-hoc networking in engineering applications is still limited. In this research, a new approach for investigating problems related to deploying ad-hoc wireless networks for supporting on-site communication and collaboration is proposed. Several modes of communication which are common in on-site applications are considered including location information, text messaging, voice and video communications, and file transmission. A prototype system is implemented for testing these modes based on available ad-hoc network protocols and using mobile devices. In addition, in order to verify our proposed approach, several tests are designed and implemented to demonstrate the usefulness of the prototype system. The results from the tests showed that our prototype system is applicable for ad-hoc wireless networks. Furthermore, a new protocol based on clustering to improve data accessibility in ad-hoc networks is tested using a simulation tool to study its performance under different scenarios. The simulation results showed the impact of the area size, wireless range, number of nodes, and node speed on data accessibility

    Effective bootstrapping of Peer-to Peer networks over Mobile Ad-hoc networks

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    Mobile Ad-hoc Networks (MANETs) and Peer-to-Peer (P2P) networks are vigorous, revolutionary communication technologies in the 21st century. They lead the trend of decentralization. Decentralization will ultimately win clients over client/server model, because it gives ordinary network users more control, and stimulates their active participation. It is a determinant factor in shaping the future of networking. MANETs and P2P networks are very similar in nature. Both are dynamic, distributed. Both use multi-hop broadcast or multicast as major pattern of traffic. Both set up connection by self-organizing and maintain connection by self-healing. Embodying the slogan networking without networks, both abandoned traditional client/server model and disclaimed pre-existing infrastructure. However, their status quo levels of real world application are widely divergent. P2P networks are now accountable for about 50 ~ 70% internet traffic, while MANETs are still primarily in the laboratory. The interesting and confusing phenomenon has sparked considerable research effort to transplant successful approaches from P2P networks into MANETs. While most research in the synergy of P2P networks and MANETs focuses on routing, the network bootstrapping problem remains indispensable for any such transplantation to be realized. The most pivotal problems in bootstrapping are: (1) automatic configuration of nodes addresses and IDs, (2) topology discovery and transformation in different layers and name spaces. In this dissertation research, we have found novel solutions for these problems. The contributions of this dissertation are: (1) a non-IP, flat address automatic configuration scheme, which integrates lower layer addresses and P2P IDs in application layer and makes simple cryptographical assignment possible. A related paper entitled Pastry over Ad-Hoc Networks with Automatic Flat Address Configuration was submitted to Elsevier Journal of Ad Hoc Networks in May. (2) an effective ring topology construction algorithm which builds perfect ring in P2P ID space using only simplest multi-hop unicast or multicast. Upon this ring, popular structured P2P networks like Chord, Pastry could be built with great ease. A related paper entitled Chord Bootstrapping on MANETs - All Roads lead to Rome will be ready for submission after defense of the dissertation

    Computer Science & Technology Series : XXI Argentine Congress of Computer Science. Selected papers

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    CACIC’15 was the 21thCongress in the CACIC series. It was organized by the School of Technology at the UNNOBA (North-West of Buenos Aires National University) in Junín, Buenos Aires. The Congress included 13 Workshops with 131 accepted papers, 4 Conferences, 2 invited tutorials, different meetings related with Computer Science Education (Professors, PhD students, Curricula) and an International School with 6 courses. CACIC 2015 was organized following the traditional Congress format, with 13 Workshops covering a diversity of dimensions of Computer Science Research. Each topic was supervised by a committee of 3-5 chairs of different Universities. The call for papers attracted a total of 202 submissions. An average of 2.5 review reports werecollected for each paper, for a grand total of 495 review reports that involved about 191 different reviewers. A total of 131 full papers, involving 404 authors and 75 Universities, were accepted and 24 of them were selected for this book.Red de Universidades con Carreras en Informática (RedUNCI

    Computer Science & Technology Series : XXI Argentine Congress of Computer Science. Selected papers

    Get PDF
    CACIC’15 was the 21thCongress in the CACIC series. It was organized by the School of Technology at the UNNOBA (North-West of Buenos Aires National University) in Junín, Buenos Aires. The Congress included 13 Workshops with 131 accepted papers, 4 Conferences, 2 invited tutorials, different meetings related with Computer Science Education (Professors, PhD students, Curricula) and an International School with 6 courses. CACIC 2015 was organized following the traditional Congress format, with 13 Workshops covering a diversity of dimensions of Computer Science Research. Each topic was supervised by a committee of 3-5 chairs of different Universities. The call for papers attracted a total of 202 submissions. An average of 2.5 review reports werecollected for each paper, for a grand total of 495 review reports that involved about 191 different reviewers. A total of 131 full papers, involving 404 authors and 75 Universities, were accepted and 24 of them were selected for this book.Red de Universidades con Carreras en Informática (RedUNCI

    Auto-Configuration of ACL Policy in Case of Topology Change in Hybrid SDN

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    © 2016 IEEE. Software-defined networking (SDN) has emerged as a new network architecture, which decouples both the control and management planes from data plane at forwarding devices. However, SDN deployment is not widely adopted due to the budget constraints of organizations. This is because organizations are always reluctant to invest too much budget to establish a new network infrastructure from scratch. One feasible solution is to deploy a limited number of SDN-enabled devices along with traditional (legacy) network devices in the network of an organization by incrementally replacing traditional network by SDN, which is called hybrid SDN (Hybrid SDN) architecture. Network management and control in Hybrid SDN are vital tasks that require significant effort and resources. Manual handling of these tasks is error prone. Whenever network topology changes, network policies (e.g., access control list) configured at the interfaces of forwarding devices (switches/routers) may be violated. That creates severe security threats for the whole network and degrades the network performance. In this paper, we propose a new approach for Hybrid SDN that auto-detects the interfaces of forwarding devices and network policies that are affected due to change in network topology. In the proposed approach, we model network-wide policy and local policy at forwarding device using a three-tuple and a six-tuple, respectively. We compute graph to represent the topology of the network. By using graph difference technique, we detect a possible change in topology. In the case of topology change, we verify policy for updated topology by traversing tree using six-tuple. If there is any violation in policy implementation, then affected interfaces are indicated and policies that need to be configured are also indicated. Then, policies are configured on the updated topology according to specification in an improved way. Simulation results show that our proposed approach enhances the network efficiency in term of successful packet delivery ratio, the ratio of packets that violated the policy and normalized overhead
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