281 research outputs found

    Optimisation of routing protocols for Wireless Mesh Networks (WMNs) to achieve higher quality of service for real time applications

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    The existing routing protocols for WMNs (Wireless Mesh Networks) are extensions of protocols originally designed for Mobile Ad-hoc Networks (MANETs) and perform sub-optimally for the mesh connectivity of WMNs which degrades their performance in terms of increased latency in packet delivery, packet drops and decreased network throughput. The proposed research, currently at its inception, would investigate into capacity and limitations of current WMN routing protocols with respect to wireless technologies, platforms and relevant standards in context of routing requirements of identified real-time applications, namely, the disaster management and tele-health applications. The research would optimise the existing routing protocols for WMNs for the proposed applications to achieve higher quality of service, reliability and security of data access to meet their specialist requirements. Wireless Mesh Networks (WMNs) are increasingly being incorporated in disaster management solutions for access to information of disaster situation to improve effectiveness of rescue services. Currently, the routing requirements of disaster solution using WMN has been researched in context of active research project, “iSurvival- Mobile Mesh Networks for Disaster Management” , which utilises specialist applications on smart phones of end-users in the disaster area to establish WMNs using available heterogeneous wireless technologies from 3G, Wi-Fi, Bluetooth and others. These WMNs provide resilient and reconfigurable digital infrastructures, with users’ smart phones acting as routers in the connected mesh networks to facilitate routing and forwarding of information in the disaster are

    Secure Routing in Wireless Mesh Networks

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    Wireless mesh networks (WMNs) have emerged as a promising concept to meet the challenges in next-generation networks such as providing flexible, adaptive, and reconfigurable architecture while offering cost-effective solutions to the service providers. Unlike traditional Wi-Fi networks, with each access point (AP) connected to the wired network, in WMNs only a subset of the APs are required to be connected to the wired network. The APs that are connected to the wired network are called the Internet gateways (IGWs), while the APs that do not have wired connections are called the mesh routers (MRs). The MRs are connected to the IGWs using multi-hop communication. The IGWs provide access to conventional clients and interconnect ad hoc, sensor, cellular, and other networks to the Internet. However, most of the existing routing protocols for WMNs are extensions of protocols originally designed for mobile ad hoc networks (MANETs) and thus they perform sub-optimally. Moreover, most routing protocols for WMNs are designed without security issues in mind, where the nodes are all assumed to be honest. In practical deployment scenarios, this assumption does not hold. This chapter provides a comprehensive overview of security issues in WMNs and then particularly focuses on secure routing in these networks. First, it identifies security vulnerabilities in the medium access control (MAC) and the network layers. Various possibilities of compromising data confidentiality, data integrity, replay attacks and offline cryptanalysis are also discussed. Then various types of attacks in the MAC and the network layers are discussed. After enumerating the various types of attacks on the MAC and the network layer, the chapter briefly discusses on some of the preventive mechanisms for these attacks.Comment: 44 pages, 17 figures, 5 table

    Ubiquitous robust communications for emergency response using multi-operator heterogeneous networks

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    A number of disasters in various places of the planet have caused an extensive loss of lives, severe damages to properties and the environment, as well as a tremendous shock to the survivors. For relief and mitigation operations, emergency responders are immediately dispatched to the disaster areas. Ubiquitous and robust communications during the emergency response operations are of paramount importance. Nevertheless, various reports have highlighted that after many devastating events, the current technologies used, failed to support the mission critical communications, resulting in further loss of lives. Inefficiencies of the current communications used for emergency response include lack of technology inter-operability between different jurisdictions, and high vulnerability due to their centralized infrastructure. In this article, we propose a flexible network architecture that provides a common networking platform for heterogeneous multi-operator networks, for interoperation in case of emergencies. A wireless mesh network is the main part of the proposed architecture and this provides a back-up network in case of emergencies. We first describe the shortcomings and limitations of the current technologies, and then we address issues related to the applications and functionalities a future emergency response network should support. Furthermore, we describe the necessary requirements for a flexible, secure, robust, and QoS-aware emergency response multi-operator architecture, and then we suggest several schemes that can be adopted by our proposed architecture to meet those requirements. In addition, we suggest several methods for the re-tasking of communication means owned by independent individuals to provide support during emergencies. In order to investigate the feasibility of multimedia transmission over a wireless mesh network, we measured the performance of a video streaming application in a real wireless metropolitan multi-radio mesh network, showing that the mesh network can meet the requirements for high quality video transmissions

    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

    Models and Protocols for Resource Optimization in Wireless Mesh Networks

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    Wireless mesh networks are built on a mix of fixed and mobile nodes interconnected via wireless links to form a multihop ad hoc network. An emerging application area for wireless mesh networks is their evolution into a converged infrastructure used to share and extend, to mobile users, the wireless Internet connectivity of sparsely deployed fixed lines with heterogeneous capacity, ranging from ISP-owned broadband links to subscriber owned low-speed connections. In this thesis we address different key research issues for this networking scenario. First, we propose an analytical predictive tool, developing a queuing network model capable of predicting the network capacity and we use it in a load aware routing protocol in order to provide, to the end users, a quality of service based on the throughput. We then extend the queuing network model and introduce a multi-class queuing network model to predict analytically the average end-to-end packet delay of the traffic flows among the mobile end users and the Internet. The analytical models are validated against simulation. Second, we propose an address auto-configuration solution to extend the coverage of a wireless mesh network by interconnecting it to a mobile ad hoc network in a transparent way for the infrastructure network (i.e., the legacy Internet interconnected to the wireless mesh network). Third, we implement two real testbed prototypes of the proposed solutions as a proof-of-concept, both for the load aware routing protocol and the auto-configuration protocol. Finally we discuss the issues related to the adoption of ad hoc networking technologies to address the fragility of our communication infrastructure and to build the next generation of dependable, secure and rapidly deployable communications infrastructures

    Wireless Mesh Network Performance for Urban Search and Rescue Missions

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    In this paper we demonstrate that the Canine Pose Estimation (CPE) system can provide a reliable estimate for some poses and when coupled with effective wireless transmission over a mesh network. Pose estimates are time sensitive, thus it is important that pose data arrives at its destination quickly. Propagation delay and packet delivery ratio measuring algorithms were developed and used to appraise Wireless Mesh Network (WMN) performance as a means of carriage for this time-critical data. The experiments were conducted in the rooms of a building where the radio characteristics closely resembled those of a partially collapsed building-a typical US&R environment. This paper presents the results of the experiments, which demonstrate that it is possible to receive the canine pose estimation data in realtime although accuracy of the results depend on the network size and the deployment environment.Comment: 19 Pages, IJCNC Journa

    Study of Performance of Security Protocols in Wireless Mesh Network

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    Wireless Mesh Networks (WMNs) represent a good solution to providing wireless Internet connectivity in a sizable geographic area; this new and promising paradigm allows for network deployment at a much lower cost than with classic WiFi networks. Standards-based wireless access takes advantage of the growing popularity of inexpensive Wi-Fi clients,enabling new service opportunities and applications that improve user productivity and responsiveness. The deployment of WMNs, are suffered by : (i) All, the communications being wireless and therefore prone to interference, present severe capacity and delay constraints, (ii) The second reason that slows down the deployment of WMNs is the lack of security guarantees. Wireless mesh networks mostly susceptible to routing protocol threats and route disruption attacks. Most of these threats require packet injection with a specialized knowledge of the routing protocol; the threats to wireless mesh networks and are summarized as (i) External attacks: in which attackers not belonging to the network jam the communication or inject erroneous information, and (ii) Internal attacks: in which attackers are internal, compromised nodes that are difficult to be detected. The MAC layers of WMN are subjected to the attacks like Eavesdropping, Link Layer Jamming Attack, MAC Spoofing Attack, and Replay Attack. The attacks in Network Layer are: Control Plane Attacks, Data Plane Attacks, Rushing attack, Wormhole attack, and Black Hole Attack. In this project work we are concern with the threats related to Network layer of WMN based upon 802.11i and analysis the performance of secure routing protocols and their performance against the intrusion detection
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