59 research outputs found

    Modeling and performance analysis of an alternative to IEEE 802.11e Hybrid Control Function

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    Modern wireless networks are offering a wide range of applications that require the efficient integration of multimedia and traditional data traffic along with QoS provision. The IEEE 802.11e workgroup has standardized a new QoS enhanced access scheme for wireless LANs, namely Hybrid Control Function (HCF). HCF consists of the Enhanced Distributed Channel Access (EDCA) and the Hybrid Control Channel Access (HCCA) protocols which manage to ensure QoS support. However, they exhibit specific weaknesses that limit network performance. This work analyzes an alternative protocol, called Priority Oriented Adaptive Polling (POAP). POAP is an integrated channel access mechanism, is collision free, it employs priorities to differentiate traffic in a proportional way, it provides fairness, and generally supports QoS for all types of multimedia applications, while efficiently serving background data traffic. POAP is compared to HCF in order to examine the wireless network performance when serving integrated traffic

    Malware Detection in the Cloud under Ensemble Empirical Mode Decomposition

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    Cloud networks underpin most of todays’ socioeconomical Information Communication Technology (ICT) environments due to their intrinsic capabilities such as elasticity and service transparency. Undoubtedly, this increased dependence of numerous always-on services with the cloud is also subject to a number of security threats. An emerging critical aspect is related with the adequate identification and detection of malware. In the majority of cases, malware is the first building block for larger security threats such as distributed denial of service attacks (e.g. DDoS); thus its immediate detection is of crucial importance. In this paper we introduce a malware detection technique based on Ensemble Empirical Mode Decomposition (E-EMD) which is performed on the hypervisor level and jointly considers system and network information from every Virtual Machine (VM). Under two pragmatic cloud-specific scenarios instrumented in our controlled experimental testbed we show that our proposed technique can reach detection accuracy rates over 90% for a range of malware samples. In parallel we demonstrate the superiority of the introduced approach after comparison with a covariance-based anomaly detection technique that has been broadly used in previous studies. Consequently, we argue that our presented scheme provides a promising foundation towards the efficient detection of malware in modern virtualized cloud environments. Index Terms—Malware Detection, Empirical Mode Decomposition, Cloud computing, Anomaly Detectio

    Exploring the intra-frame energy conservation capabilities of the horizontal simple packing algorithm in IEEE 802.16e networks: an analytical approach

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    The power saving capabilities of the mobile devices in broadband wireless networks constitute a challenging research topic that has attracted the attention of researchers recently, while it needs to be addressed at multiple layers. This work provides a novel analysis of the intra-frame energy conservation potentials of the IEEE 802.16e network. Specifically, the power saving capabilities of the worldwide interoperability for microwave access downlink sub-frame are thoroughly studied, employing the well-known simple packing algorithm as the mapping technique of the data requests. The accurate mathematical model, cross-validated via simulation, reveals the significant ability to conserve energy in this intra-frame fashion under different scenarios. To the best of our knowledge, this is the first work providing intra-frame power-saving potentials of IEEE 802.16 networks. Additionally, this is the first study following an analytic approach

    An Iterative and Toolchain-Based Approach to Automate Scanning and Mapping Computer Networks

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    As today's organizational computer networks are ever evolving and becoming more and more complex, finding potential vulnerabilities and conducting security audits has become a crucial element in securing these networks. The first step in auditing a network is reconnaissance by mapping it to get a comprehensive overview over its structure. The growing complexity, however, makes this task increasingly effortful, even more as mapping (instead of plain scanning), presently, still involves a lot of manual work. Therefore, the concept proposed in this paper automates the scanning and mapping of unknown and non-cooperative computer networks in order to find security weaknesses or verify access controls. It further helps to conduct audits by allowing comparing documented with actual networks and finding unauthorized network devices, as well as evaluating access control methods by conducting delta scans. It uses a novel approach of augmenting data from iteratively chained existing scanning tools with context, using genuine analytics modules to allow assessing a network's topology instead of just generating a list of scanned devices. It further contains a visualization model that provides a clear, lucid topology map and a special graph for comparative analysis. The goal is to provide maximum insight with a minimum of a priori knowledge.Comment: 7 pages, 6 figure

    IEEE 802.11ax Spatial Reuse Improvement: An Interference-Based Channel Access Algorithm

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    Wi-Fi is the dominant way of connecting indoor mobile devices to the Internet. The main reason behind the huge adoption of this technology is the simplicity of IEEE 802.11 protocols which in turn offer low-cost ownership and maintenance combined with the ability to offer high data rates to end users. The increasing demand in traffic volumes leads to the continuous deployment of access points (APs) resulting in densification of the IEEE 802.11 networks. This fact, instead of enhancing the efficiency of wireless local area networks (WLANs) degrades their overall performance due to cochannel interference between overlapped basic services sets (OBSSs). One of the main goals of the under-development IEEE 802.11ax amendment is to address the WLAN densification problem by improving spatial reuse (SR). In this article we present and evaluate a channel access algorithm, which considers the expected interference that nodes will suffer by a concurrent transmission so to decide if transmission or defer will take place. It is shown that the proposed interference based dynamic channel algorithm (IB-DCA) offers significant SR performance gains comparing to the existing channel access algorithms, in terms of the station mean data rate, for all the stations in a IEEE 802.11ax dense deployment

    MOOC as a Way of Dissemination, Training and Learning of Telecommunication Engineering

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    In this chapter, the use of massive open online courses (MOOCs) for the dissemination, training capabilities and learning of telecommunication engineering is described taking as example the successful MOOC ‘Ultra- Dense Networks for 5G and its Evolution’ developed under the European innovative training network (ITN) TeamUp5G. MOOCs are usually understood as a way of teaching or learning for massive potential students. Indeed, this is the main goal of any MOOC. However, we also propose its use for training and dissemination. The ITN TeamUp5G is a training network for 15 PhD students of seven different institutions (universities and companies) where the students make research on different interconnected topics for the common goal of Ultra dense networks for 5G. At the same time they researched, they prepared a MOOC to disseminate their most recent advances and their challenges. For the MOOC, they needed to collect their thoughts, organizse their knowledge and establish a common vision of the whole system. The cooperative work, the cross-related meetings and, the preparation of all the materials for the MOOC were very interesting and useful in their training process. The whole experience of designing and creating the MOOC is described in detail along with the challenges and lessons learned.info:eu-repo/semantics/acceptedVersio

    AWPP: A New Scheme for Wireless Access Control Proportional to Traffic Priority and Rate

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    Cutting-edge wireless networking approaches are required to efficiently differentiate traffic and handle it according to its special characteristics. The current Medium Access Control (MAC) scheme which is expected to be sufficiently supported by well-known networking vendors comes from the IEEE 802.11e workgroup. The standardized solution is the Hybrid Coordination Function (HCF), that includes the mandatory Enhanced Distributed Channel Access (EDCA) protocol and the optional Hybrid Control Channel Access (HCCA) protocol. These two protocols greatly differ in nature and they both have significant limitations. The objective of this work is the development of a high-performance MAC scheme for wireless networks, capable of providing predictable Quality of Service (QoS) via an efficient traffic differentiation algorithm in proportion to the traffic priority and generation rate. The proposed Adaptive Weighted and Prioritized Polling (AWPP) protocol is analyzed, and its superior deterministic operation is revealed

    A review of communication-oriented optical wireless systems

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