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    NETWORKS & SECURITY
  • NETWORKS & SECURITY
    Sahil Sholla, Roohie Naaz, Mohammad Ahsan Chishti
    2017, 14(5): 160-173.
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    A novel initiative in providing advanced civic amenities is the idea of smart city driven by the Internet of Things. Owing to a lack of consensus regarding what constitutes a smart city, diverse smart city architectures have been proposed. However, it is observed that adequate consideration is not given to the most important element of a smart city i.e. its people. In our opinion, energy efficient technologically driven city does not necessarily lead to a smart city. Ethics, tradition and law form essential ingredients of complex social palette that cannot be ignored. In this work we propose Ethics-Aware Object-Oriented Smart City Architecture (EOSCA) that has two distinguishing features. Firstly, we propose an object oriented layered architecture where an object represents an abstraction of a real world thing along with requisite security and ethics parameters. Secondly, we propose to integrate socio-cultural and ethical aspects within the smart city architecture by dedicating a separate ethics layer. Such enhancement not only addresses the challenge of privacy and security of a smart city, but also makes it people friendly by incorporating ethics. Such measures would facilitate social acceptance of smart city paradigm and augment its economic value.
  • NETWORKS & SECURITY
    Zhen Wang, Jianqing Li, Manlin Fang, Yang Li, Botao Feng
    2017, 14(5): 174-184.
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    The intelligent vehicle network uses advanced information technology to establish an efficient integrated vehicle transport system, which has received great attention in industry and academia. Internet of Vehicles (IoV) in an urban environment is operated in a wireless environment with high bit error rate and interference. In addition, the wireless link between vehicles is likely to be lost. All of this makes it an important challenge to provide reliable mobile routing in an urban traffic environment. In this paper, a reliable routing algorithm with network coding (RR_NC) is proposed to solve the above problems. A routing node sequence is discovered in IoV from source to destination by multi-metric ant colony optimization algorithm (MACO), and then clusters are formed around every node in the sequence. By adding linear encoding into the transmission of data between vehicle's clusters, the RR_NC provides much more reliable transmission and can recover the original message in the event of disorder and loss of message. Simulations are taken under different scenarios, and the results prove that this novel algorithm can deliver the information more reliably between vehicles in real-time with lower data loss and communication overhead.
  • SIGNAL PROCESSING FOR COMMUNICATIONS
  • SIGNAL PROCESSING FOR COMMUNICATIONS
    Zhonghua Liang, Junshan Zang, Xiaojun Yang, Xiaodai Dong, Huansheng Song
    2017, 14(5): 185-192.
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    Integration interval and decision threshold issues were investigated for improved transmitted reference pulse cluster (iTRPC-) ultra-wideband (UWB) systems. Our analysis shows that the bit error rate (BER) performance of iTRPC-UWB systems can be significantly improved via integration interval determination (IID) and decision threshold optimization. For this purpose, two modifications can be made at the autocorrelation receiver as follows. Firstly, the IID processing is performed for autocorrelation operation to capture multi-path energy as much as possible. Secondly, adaptive decision threshold (ADT) instead of zero decision threshold (ZDT), is used as estimated optimal decision threshold for symbol detection. Performance of iTRPC-UWB systems using IID and ADT was evaluated in realistic IEEE 802.15.4a UWB channel models and the simulation results demonstrated our theoretical analysis.
  • SIGNAL PROCESSING FOR COMMUNICATIONS
    Arsla Khan, Amna Arif, Tabassum Nawaz, Sobia Baig
    2017, 14(5): 193-206.
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    This article proposes a new transceiver design for Single carrier frequency division multiple access (SCFDMA) system based on discrete wavelet transform (DWT). SCFDMA offers almost same structure as Orthogonal frequency division multiple access (OFDMA) with extra advantage of low Peak to Average Power Ratio (PAPR). Moreover, this article also suggests the application of Walsh Hadamard transform (WHT) for linear precoding (LP) to improve the PAPR performance of the system. Supremacy of the proposed transceiver over conventional Fast Fourier transform (FFT) based SCFDMA is shown through simulated results in terms of PAPR, spectral efficiency (SE) and bit error rate (BER).
  • SIGNAL PROCESSING FOR COMMUNICATIONS
    Xiaolong Yang, Xuezhi Tan
    2017, 14(5): 207-217.
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    Cognitive radio is considered as an efficient way to improve the spectrum efficiency. As one of its key technologies, spectrum handoff can guarantee the transmission continuity of secondary users (SUs). In this paper, we address a new and more generalized spectrum handoff problem in cognitive radio networks (CRNs), by considering simultaneously energy efficiency, multiple spectrum handoffs and multiple channels. Furthermore, effects of the primary users' (PUs') arrival and service rate on the target channel sequence selection are also considered. In order to obtain the energy-efficient target channel sequence, we firstly analyze the energy consumption and the number of delivered bits per hertz in the spectrum handoff process, and formulate a ratio-type energy efficiency optimization problem, which can be transformed into a parametric problem by utilizing fractional programming. Then, we propose an algorithm combining dynamic programming with bisection (DPB) algorithm to solve the energy efficiency optimization problem. Our simulation results verify that the designed target channel sequence has better performance than the existing algorithms in terms of energy efficiency.