2,271 research outputs found

    A Survey on Wireless Security: Technical Challenges, Recent Advances and Future Trends

    Full text link
    This paper examines the security vulnerabilities and threats imposed by the inherent open nature of wireless communications and to devise efficient defense mechanisms for improving the wireless network security. We first summarize the security requirements of wireless networks, including their authenticity, confidentiality, integrity and availability issues. Next, a comprehensive overview of security attacks encountered in wireless networks is presented in view of the network protocol architecture, where the potential security threats are discussed at each protocol layer. We also provide a survey of the existing security protocols and algorithms that are adopted in the existing wireless network standards, such as the Bluetooth, Wi-Fi, WiMAX, and the long-term evolution (LTE) systems. Then, we discuss the state-of-the-art in physical-layer security, which is an emerging technique of securing the open communications environment against eavesdropping attacks at the physical layer. We also introduce the family of various jamming attacks and their counter-measures, including the constant jammer, intermittent jammer, reactive jammer, adaptive jammer and intelligent jammer. Additionally, we discuss the integration of physical-layer security into existing authentication and cryptography mechanisms for further securing wireless networks. Finally, some technical challenges which remain unresolved at the time of writing are summarized and the future trends in wireless security are discussed.Comment: 36 pages. Accepted to Appear in Proceedings of the IEEE, 201

    Influence of technical improvements on the business case for a mobile WiMAX network

    Get PDF
    From a technical point of view, Mobile WiMAX may offer an appropriate solution for delivering broadband wireless access. Two remaining questions, however, are whether the rollout of a WiMAX network is economically feasible or not, and how technical improvements like MIMO, beamforming and turbo-coding can influence the business case. In this paper different technical scenarios for a Mobile WiMAX rollout are defined and evaluated from an economic as well as a technical perspective. To obtain realistic figures, we have defined a business case for a Mobile WiMAX rollout in Belgium, a country with a high wired broadband penetration. Further, we give an indication about the feasibility of a Mobile WiMAX network related to the population density. Finally, as the introduction of a new technology involves a lot of uncertainties, a detailed sensitivity analysis on both the economic and technical input parameters is performed to determine the most influencing parameters

    Performance of MB-OFDM UWB and WiMAX IEEE 802.16e converged radio-over-fiber in PON

    Get PDF
    Experimental results about the performance of converged radio-over- fiber transmission including multiband- OFDM UWB and WiMAX 802.16e wireless over a passive optical network are reported in this paper. The experimental study indicates that UWB and WiMAX converged transmission is feasible over the proposed distribution set-up employing a single wavelength. However, the results indicate that there is an EVM penalty of 3.2 dB for a UWB 10 km SSMF transmission in presence of WiMAX wireless

    Quantifying Potential Energy Efficiency Gain in Green Cellular Wireless Networks

    Full text link
    Conventional cellular wireless networks were designed with the purpose of providing high throughput for the user and high capacity for the service provider, without any provisions of energy efficiency. As a result, these networks have an enormous Carbon footprint. In this paper, we describe the sources of the inefficiencies in such networks. First we present results of the studies on how much Carbon footprint such networks generate. We also discuss how much more mobile traffic is expected to increase so that this Carbon footprint will even increase tremendously more. We then discuss specific sources of inefficiency and potential sources of improvement at the physical layer as well as at higher layers of the communication protocol hierarchy. In particular, considering that most of the energy inefficiency in cellular wireless networks is at the base stations, we discuss multi-tier networks and point to the potential of exploiting mobility patterns in order to use base station energy judiciously. We then investigate potential methods to reduce this inefficiency and quantify their individual contributions. By a consideration of the combination of all potential gains, we conclude that an improvement in energy consumption in cellular wireless networks by two orders of magnitude, or even more, is possible.Comment: arXiv admin note: text overlap with arXiv:1210.843

    High speed short range optical wireless ground-to-train communications

    Get PDF
    There is a huge demand for seamless high-speed communications in fast moving trains. People want broadband services while on board as in their home or in the workplace. This demand drives the motivation for a high speed dedicated optical wireless link. Here we propose a free space optical ground-to-train communications system which consists of optical transceivers placed on the train and along the railway track. A mathematical model for three different scenarios when the train is moving has been developed. The optical link analysis, results as well as a simple proof of concept are also presented

    Green Femtocell Based on UWB Technologies

    Get PDF

    Joint distribution of polarization-multiplexed UWB and WiMAX radio in PON

    Get PDF
    In this paper, the feasibility of the joint distribution of ultra-wideband (UWB) and WIMAX wireless using polarization multiplexing as a coexistence technique is proposed and experimentally demonstrated within the framework of passive optical networks (PON). Four single- and orthogonal-polarization multiplexing schemes are studied targeting to reduce the mutual interference when UWB and WiMAX are distributed jointly through standard single-mode fiber (SSMF) without transmission impairments compensation techniques and amplification. Experimental results indicate successful transmission up to 25 km, in SSMF exceeding the range in typical PON deployments. The radio link penalty introduced by optical transmission is also investigated in this paper

    System level evaluation of interference in vehicular mobile broadband networks

    Get PDF
    corecore