Effective data routing using mobile sinks in disjoint mobile wireless sensor networks

In Mobile WSNs (MWSNs), disjoint clusters could be naturally formed in an unpredictable way that possess the nature of highly dynamic connected and disconnected schema. Many partitions of the network could happen in disjoint mobile wireless sensor networks (DMWSNs), and could last for a significant amount of time that can challenge current routing protocols in crisis-driven and geography-driven applications. We propose in this paper, two new centralized and distributed routing discovery protocols for DMWSN. In the centralized protocol, the static sink controls the motion of mobile sinks. In the distributed protocol, each mobile sink is responsible for collecting data in a specific region. In our work, the mobile sinks need to coordinate among themselves for communication with the base station (BS). The simulation results shows the advantage of our newly proposed protocols in terms of time delay, energy consumed, and the delivery ratio

Directional Routing Techniques in VANET

Vehicle Ad hoc Networks (VANET) emerged as a subset of the Mobile Ad hoc Network (MANET) application; it is considered to be a substantial approach to the ITS (Intelligent Transportation System). VANETs were introduced to support drivers and improve safety issues and driving comfort, as a step towards constructing a safer, cleaner and more intelligent environment. At the present time vehicles are equipped with a number of sensors and devices, including On Board Units (OBU); this enables vehicles to sense situations affecting other vehicles and manage communications, by exploiting infrastructures such as the Road Side Unit (RSU); creating a Vehicle to Infrastructure (V2I) pathway, or interacting directly with other vehicles creating a Vehicle to Vehicle (V2V) pathway. Owing to the lack of infrastructures and difficulties involved in providing comprehensive coverage for all roads because of the high expense associated with installation, the investigation in this research concentrates on the V2V communication type rather than theV2I communication type. Many challenges have emerged in VANET, encouraging researchers to investigate their research in an attempt to meet these challenges. Routing protocol issues are considered to be a critical dilemma that needs to be tackled in VANET, particularly in a sparse environment, by designing an effcient routing mechanism that impacts on enhancing network performance in terms of disseminating messages to a desireddestination, balancing the generated packet (overhead) on the network and increasing the ratio of packet delivery with a reduced time delay. VANET has some unique characteristics compared to MANET; specifically it includes high mobility and constrained patterns restricted by roads, which lead to generation of a disconnected area occurring continuously between vehicles creating a Delay Tolerant Network (DTN). This is in opposition to applying the multi-hope technique properly to deliver the packet to its desire destination. The aim in this thesis comprises two main contributions. First developing novel routing protocols for a sparse environment in VANET with the context of utilising the mobility feature, with the aid of the equipped devices, such as Global Position System (GPS) and Navigation System (NS). This approach exploits the knowledge of Second Heading Direction (SHD), which represents the knowledge of the next road direction the vehicle is intending to take, in order to increase the packet delivery ratio, and to increase the route stability by decreasing instances of route breakage. This approach comprises two approaches; the first approach was designed for a highway scenario, by selecting the next hop node based on a filtration process, to forward the packet to the desired destination, while the second approach was developed for the intersection and roundabout scenario, in order to deliver the packet to the destination (unknown location). The formalising and specification of the VSHDRP has been performed using the CCA (Calculus of Context-aware Ambient), in order to evaluate the protocols behaviours, the protocol has been validated using the ccaPL. In addition the performance of the VSHDRP has been evaluated using the NS-2 simulator; comparing it with Greedy Perimeter Stateless Routing (GPSR) protocol, to reveal the strengths and weaknesses of the protocol. Second, developing a novel approach to broadcasting the HELLO beacon message adaptively in VANET based on the node's circumstances (direction and speed), in order to minimise the broadcasting of unnecessary HELLO beacon messages. A novel architecture has been built based on the adaptive HELLO beacon message, which clarifies how the OBU components are interacting with the connected sensors, in order to portray any changes in the vehicle's circumstances, so as to take the right decision to determine appropriate action. This architecture has been built based on the concept of a context aware system, which divides the architecture into three main phases; sensing processing and acting

Sending and Receiving Internet Messages from Disconnected Areas

Over 62% of the world is connected to the internet with more than 6.9 billion smartphone users. The omnipresence of technology in the form of the internet and smartphones have led to constant research in improving communication throughout the world. But even today, 37% (2.9 billion people) are not connected to the internet even though most of the people in such areas have smartphones. To solve this problem of access to internet services in disconnected areas, a software-only mobile-first approach has been proposed for disconnected data distribution infrastructure which can support different internet applications in limited connectivity. A prototype application based on Signal Messenger has been created to allow users to send and receive internet messages without the need for internet connectivity. This solution can help bridge the digital divide, improving access to critical communication services in disconnected areas

An Integrated Testbed for Cooperative Perception with Heterogeneous Mobile and Static Sensors

Cooperation among devices with different sensing, computing and communication capabilities provides interesting possibilities in a growing number of problems and applications including domotics (domestic robotics), environmental monitoring or intelligent cities, among others. Despite the increasing interest in academic and industrial communities, experimental tools for evaluation and comparison of cooperative algorithms for such heterogeneous technologies are still very scarce. This paper presents a remote testbed with mobile robots and Wireless Sensor Networks (WSN) equipped with a set of low-cost off-the-shelf sensors, commonly used in cooperative perception research and applications, that present high degree of heterogeneity in their technology, sensed magnitudes, features, output bandwidth, interfaces and power consumption, among others. Its open and modular architecture allows tight integration and interoperability between mobile robots and WSN through a bidirectional protocol that enables full interaction. Moreover, the integration of standard tools and interfaces increases usability, allowing an easy extension to new hardware and software components and the reuse of code. Different levels of decentralization are considered, supporting from totally distributed to centralized approaches. Developed for the EU-funded Cooperating Objects Network of Excellence (CONET) and currently available at the School of Engineering of Seville (Spain), the testbed provides full remote control through the Internet. Numerous experiments have been performed, some of which are described in the paper

On the Design of Future Communication Systems with Coded Transport, Storage, and Computing

Communication systems are experiencing a fundamental change. There are novel applications that require an increased performance not only of throughput but also latency, reliability, security, and heterogeneity support from these systems. To fulfil the requirements, future systems understand communication not only as the transport of bits but also as their storage, processing, and relation. In these systems, every network node has transport storage and computing resources that the network operator and its users can exploit through virtualisation and softwarisation of the resources. It is within this context that this work presents its results. We proposed distributed coded approaches to improve communication systems. Our results improve the reliability and latency performance of the transport of information. They also increase the reliability, flexibility, and throughput of storage applications. Furthermore, based on the lessons that coded approaches improve the transport and storage performance of communication systems, we propose a distributed coded approach for the computing of novel in-network applications such as the steering and control of cyber-physical systems. Our proposed approach can increase the reliability and latency performance of distributed in-network computing in the presence of errors, erasures, and attackers

High Performance Communication Framework for Mobile Sinks Wireless Sensor Networks

A wireless sensor networks typically consist of thousand of nodes and each node has limited power, processing and bandwidth resources. Harvesting advances in the past decade in microelectronics, sensing, wireless communications and networking, sensor networks technology is expected to have a significant impact on our lives in the twenty-first century. Proposed applications of sensor networks include environmental monitoring, natural disaster prediction and relief, homeland security, healthcare, manufacturing, transportation, and home appliances and entertainment. However, Communication is one of the major challenges in wireless sensor networks as it is the main source for energy depletion. Improved network lifetime is a fundamental challenge of wireless sensor networks. Many researchers have proposed using mobile sinks as one possible solution to improve the lifetime of wireless sensor networks. The reason is that the typical manyto- one communication traffic pattern in wireless sensor networks imposes a heavy forwarding load on the nodes close to the sinks. However, it also introduces many research challenges such as the high communication overhead for updating the dynamic routing paths to connect to mobile sinks and packet loss problems while transmitted messages to mobile sinks. Therefore, our goal is to design a robust and efficient routing framework for both non-geographic aware and geographic aware mobile sinks wireless sensor networks. In order to achieve this goal in non-geographic based mobile sinks wireless sensor networks, we proposed a spider-net zone routing protocol to improve network efficiency and lifetime. Our proposed routing protocol utilise spider web topology inspired by the way spiders hunt prey in their web to provide reliable and high performance data delivery to mobile sinks. For routing in geographic aware based mobile sinks wireless sensor networks, we proposed a fault-tolerant magnetic coordinate routing algorithm to allow these network sensors to take advantage of geographic knowledge to build a routing protocol. Our proposed routing algorithm incorporates a coordinated routing algorithm for grid based network topology to improve network performance. Our third contribution is a component level fault diagnosis scheme for wireless sensor networks. The advantage of this scheme, causal model fault diagnosis, is that it can "deeply understand" and express the relationship among failure behaviours and node system components through causal relations. The above contributions constitute a novel routing framework to address the routing challenges in mobile sinks wireless sensor networks, Our framework considers both geographic and non-geographic aware based sensor networks to achieve energy efficient, high performance and network reliability. We have analyzed the proposed protocols and schemes and evaluated their performances using analytical study and simulations. The evaluation was based on the most important metries in wireless sensor networks, such as: power consumption and average delay. The evaluation shows that our solution is more energy efficient, improves the network performance, and provides data reliability in mobile sinks wireless sensor networks

Secure Communication in Disaster Scenarios

Während Naturkatastrophen oder terroristischer Anschläge ist die bestehende Kommunikationsinfrastruktur häufig überlastet oder fällt komplett aus. In diesen Situationen können mobile Geräte mithilfe von drahtloser ad-hoc- und unterbrechungstoleranter Vernetzung miteinander verbunden werden, um ein Notfall-Kommunikationssystem für Zivilisten und Rettungsdienste einzurichten. Falls verfügbar, kann eine Verbindung zu Cloud-Diensten im Internet eine wertvolle Hilfe im Krisen- und Katastrophenmanagement sein. Solche Kommunikationssysteme bergen jedoch ernsthafte Sicherheitsrisiken, da Angreifer versuchen könnten, vertrauliche Daten zu stehlen, gefälschte Benachrichtigungen von Notfalldiensten einzuspeisen oder Denial-of-Service (DoS) Angriffe durchzuführen. Diese Dissertation schlägt neue Ansätze zur Kommunikation in Notfallnetzen von mobilen Geräten vor, die von der Kommunikation zwischen Mobilfunkgeräten bis zu Cloud-Diensten auf Servern im Internet reichen. Durch die Nutzung dieser Ansätze werden die Sicherheit der Geräte-zu-Geräte-Kommunikation, die Sicherheit von Notfall-Apps auf mobilen Geräten und die Sicherheit von Server-Systemen für Cloud-Dienste verbessert

Network Coding Applications

Network coding is an elegant and novel technique introduced at the turn of the millennium to improve network throughput and performance. It is expected to be a critical technology for networks of the future. This tutorial deals with wireless and content distribution networks, considered to be the most likely applications of network coding, and it also reviews emerging applications of network coding such as network monitoring and management. Multiple unicasts, security, networks with unreliable links, and quantum networks are also addressed. The preceding companion deals with theoretical foundations of network coding