70 research outputs found

    A one hop overlay system for Mobile Ad Hoc Networks

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    Peer-to-Peer (P2P) overlays were initially proposed for use with wired networks. However, the very rapid proliferation of wireless communication technology has prompted a need for adoption of P2P systems in mobile networks too. There are many common characteristics between P2P overlay networks and Mobile Ad-hoc Networks (MANET). Self-organization, decentralization, a dynamic nature and changing topology are the most commonly shared features. Furthermore, when used together, the two approaches complement each other. P2P overlays provide data storage/retrieval functionality and MANET provides wireless connectivity between clients without depending on any pre-existing infrastructure. P2P overlay networks can be deployed over MANET to address content discovery issues. However, previous research has shown that deploying P2P systems straight over MANET does not exhibit satisfactory performance. Bandwidth limitation, limited resources and node mobility are some of the key constraints. This thesis proposes a novel approach, OneHopOverlay4MANET, to exploit the synergies between MANET and P2P overlays through cross-layering. It combines Distributed Hash Table (DHT) based structured P2P overlays with MANET underlay routing protocols to achieve one logical hop between any pair of overlay nodes. OneHopOverlay4MANET constructs a cross-layer channel to permit direct exchange of routing information between the Application layer, where the overlay operates, and the MANET underlay layer. Consequently, underlay routing information can be shared and used by the overlay. Thus, OneHopOverlay4MANET reduces the typical management traffic when deploying traditional P2P systems over MANET. Moreover, as a result of building one hop overlay, OneHopOverlay4MANET can eliminate the mismatching issue between overlay and underlay and hence resolve key lookups in a short time, enhancing the performance of the overlay. v In this thesis, we present OneHopOverlay4MANET and evaluate its performance when combined with different underlay routing protocols. OneHopOverlay4MANET has been combined with two proactive underlays (OLSR and BATMAN) and with three reactive underlay routing protocols (DSR, AODV and DYMO). In addition, the performance of the proposed system over OLSR has been compared to two recent structured P2P over MANET systems (MA-SP2P and E-SP2P) that adopted OLSR as the routing protocol. The results show that better performance can be achieved using OneHopOverlay4MANET

    Integrating peer-to-peer functionalities and routing in mobile ad-hoc networks

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    Mobile Ad-hoc Networks (MANETs) impose strict requirements in terms of battery life, communication overhead and network latency, therefore optimization should be made to applications and services such as domain name service (DNS), dynamic host configuration protocol (DHCP) and session initiation protocol (SIP) if they are to be considered for use on MANETs. Due to the decentralized and self-organizing nature of MANETs, such applications could utilize a distributed name resolution/data storage service. Distributed Hash Tables (DHTs) enable these features by virtually organizing the network topology in a peer-to-peer (P2P) overlay. P2P overlays have been designed to operate on the application layer without knowledge of the underlying network thus causing poor performance. To address this problem, we propose and evaluate two different DHTs integrated with MANET routing in order to optimize the overall performance of MANET communications when P2P applications and services are used. Both architectures share the same functionality such as decentralization, self-reorganization, and self-healing but differ in MANET routing protocol. Performance evaluation using the NS2 simulator shows that these architectures are suited to different scenarios namely increasing network size and peer velocity. Comparisons with other well-known solutions have proven their efficiency with regard to the above requirements

    DistB-Condo: Distributed Blockchain-based IoT-SDN Model for Smart Condominium

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    Condominium network refers to intra-organization networks, where smart buildings or apartments are connected and share resources over the network. Secured communication platform or channel has been highlighted as a key requirement for a reliable condominium which can be ensured by the utilization of the advanced techniques and platforms like Software-Defined Network (SDN), Network Function Virtualization (NFV) and Blockchain (BC). These technologies provide a robust, and secured platform to meet all kinds of challenges, such as safety, confidentiality, flexibility, efficiency, and availability. This work suggests a distributed, scalable IoT-SDN with Blockchain-based NFV framework for a smart condominium (DistB-Condo) that can act as an efficient secured platform for a small community. Moreover, the Blockchain-based IoT-SDN with NFV framework provides the combined benefits of leading technologies. It also presents an optimized Cluster Head Selection (CHS) algorithm for selecting a Cluster Head (CH) among the clusters that efficiently saves energy. Besides, a decentralized and secured Blockchain approach has been introduced that allows more prominent security and privacy to the desired condominium network. Our proposed approach has also the ability to detect attacks in an IoT environment. Eventually, this article evaluates the performance of the proposed architecture using different parameters (e.g., throughput, packet arrival rate, and response time). The proposed approach outperforms the existing OF-Based SDN. DistB-Condo has better throughput on average, and the bandwidth (Mbps) much higher than the OF-Based SDN approach in the presence of attacks. Also, the proposed model has an average response time of 5% less than the core model

    Performance Enhancement of MANET based on Cross-layered Reconfigurable Hierarchical Routing Protocol

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    High speed data communication is the demanding factor in both commercial and defence applications. Several algorithms are proposed to support the high-speed data exchange while ensuring the quality, performance and reliability. However, there is still a gap, citing various compatibility issues with variety of transceiver technologies. This paper proposes a novel algorithm for enhancing the performance of mobile ad-hoc networks using Free-Space Optics (FSO). The FSO has the natural ability to the interference while capable of large bandwidth and excellent compatibility. Low power and adaptability are the features with which it has contributed to the latest technologies like storage area network, wireless area network etc. The proposed work uses optical spheres with a multi-transceiver system and a cross-layered reconfigurable routing mechanism. Parameters such as delay, residual energy, throughput, and drop are verified for the Crosslayered Reconfigurable Hierarchical Routing Optical Sphere (CRHROS) protocol for varying numbers of optical transceivers. The proposed work also compares the performance of two traffic sources, Constant Bit Rate (CBR) and Variable Bit Rate (VBR), for the proposed algorithm

    A lightweight distributed super peer election algorithm for unstructured dynamic P2P systems

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    Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia Electrotécnica e de ComputadoresNowadays with the current growth of information exchange, and the increasing mobility of devices, it becomes essential to use technology to monitor this development. For that P2P networks are used, the exchange of information between agencies is facilitated, these now being applied in mobile networks, including MANETs, where they have special features such as the fact that they are semi-centralized, where it takes peers more ability to make a greater role in the network. But those peer with more capacity, which are used in the optimization of various parameters of these systems, such as optimization\to research, are difficult to identify due to the fact that the network does not have a fixed topology, be constantly changing, (we like to go online and offline, to change position, etc.) and not to allow the exchange of large messages. To this end, this thesis proposes a distributed election algorithm of us greater capacity among several possible goals, enhance research in the network. This includes distinguishing characteristics, such as election without global knowledge network, minimal exchange of messages, distributed decision made without dependence on us and the possibility of influencing the election outcome as the special needs of the network

    Scalable and Secure Multicast Routing for Mobile Ad-hoc Networks

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    Mobile Ad-Hoc Networks (MANETs) are decentralized and autonomous communication systems: They can be used to provide connectivity when a natural disaster has brought down the infrastructure, or they can support freedom of speech in countries with governmental Internet restrictions. MANET design requires careful attention to scalability and security due to low-capacity and error-prone wireless links as well as the openness of these systems. In this thesis, we address the issue of multicast as a means to efficiently support the MANET application of group communication on the network layer. To this aim, we first survey the research literature on the current state of the art in MANET routing, and we identify a gap between scalability and security in multicast routing protocols–two aspects that were only considered in isolation until now. We then develop an explicit multicast protocol based on the design of a secure unicast protocol, aiming to maintain its security properties while introducing minimal overhead. Our simulation results reveal that our protocol reduces bandwidth utilization in group communication scenarios by up to 45 % compared to the original unicast protocol, while providing significantly better resilience under blackhole attacks. A comparison with pure flooding allows us to identify a practical group size limit, and we present ideas for better large-group support

    Wireless Sensor Network Virtualization: A Survey

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    Wireless Sensor Networks (WSNs) are the key components of the emerging Internet-of-Things (IoT) paradigm. They are now ubiquitous and used in a plurality of application domains. WSNs are still domain specific and usually deployed to support a specific application. However, as WSN nodes are becoming more and more powerful, it is getting more and more pertinent to research how multiple applications could share a very same WSN infrastructure. Virtualization is a technology that can potentially enable this sharing. This paper is a survey on WSN virtualization. It provides a comprehensive review of the state-of-the-art and an in-depth discussion of the research issues. We introduce the basics of WSN virtualization and motivate its pertinence with carefully selected scenarios. Existing works are presented in detail and critically evaluated using a set of requirements derived from the scenarios. The pertinent research projects are also reviewed. Several research issues are also discussed with hints on how they could be tackled.Comment: Accepted for publication on 3rd March 2015 in forthcoming issue of IEEE Communication Surveys and Tutorials. This version has NOT been proof-read and may have some some inconsistencies. Please refer to final version published in IEEE Xplor

    DESIGN OF MOBILE DATA COLLECTOR BASED CLUSTERING ROUTING PROTOCOL FOR WIRELESS SENSOR NETWORKS

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    Wireless Sensor Networks (WSNs) consisting of hundreds or even thousands of nodes, canbe used for a multitude of applications such as warfare intelligence or to monitor the environment. A typical WSN node has a limited and usually an irreplaceable power source and the efficient use of the available power is of utmost importance to ensure maximum lifetime of eachWSNapplication. Each of the nodes needs to transmit and communicate sensed data to an aggregation point for use by higher layer systems. Data and message transmission among nodes collectively consume the largest amount of energy available in WSNs. The network routing protocols ensure that every message reaches thedestination and has a direct impact on the amount of transmissions to deliver messages successfully. To this end, the transmission protocol within the WSNs should be scalable, adaptable and optimized to consume the least possible amount of energy to suite different network architectures and application domains. The inclusion of mobile nodes in the WSNs deployment proves to be detrimental to protocol performance in terms of nodes energy efficiency and reliable message delivery. This thesis which proposes a novel Mobile Data Collector based clustering routing protocol for WSNs is designed that combines cluster based hierarchical architecture and utilizes three-tier multi-hop routing strategy between cluster heads to base station by the help of Mobile Data Collector (MDC) for inter-cluster communication. In addition, a Mobile Data Collector based routing protocol is compared with Low Energy Adaptive Clustering Hierarchy and A Novel Application Specific Network Protocol for Wireless Sensor Networks routing protocol. The protocol is designed with the following in mind: minimize the energy consumption of sensor nodes, resolve communication holes issues, maintain data reliability, finally reach tradeoff between energy efficiency and latency in terms of End-to-End, and channel access delays. Simulation results have shown that the Mobile Data Collector based clustering routing protocol for WSNs could be easily implemented in environmental applications where energy efficiency of sensor nodes, network lifetime and data reliability are major concerns
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