Frequency: Quarterly E- ISSN: 2277-2235 P- ISSN: 2349-3488 Abstracted/ Indexed in: CNKI Scholar (China National Knowledge Infrastructure), Ulrichâ??s International Periodical Directory, Google Scholar, SCIRUS, Genamics JournalSeek
Quarterly published in print and online â??Inventi Rapid/Impact: Computer Networks & Communicationsâ?? publishes high quality unpublished as well as high impact pre-published research and reviews catering to the needs of researchers and professional engineers. The journal deals with multiple aspects of computer networks & communications such as: Network Protocols & Wireless Networks, Network Architectures, Next Generation Internet, Ubiquitous Networks, Heterogeneous Wireless Networks, Self-Organizing Networks and Networked Systems, and Optical Networking etc.
With the development of SDN, end-to-end network reservation becomes a reality. Resource reservation can\nbecome an online service for network users, and the network faces new challenges on how to allocate users�\nresource dynamically. To solve the problem, this paper proposed a bat-based algorithm for SDN network\nscheduling along with a network request model. The network resource request model is for characterizing users�\nsimultaneous network resource request in SDN. Based on the model, this paper transforms the resource reservation\nproblem into a multiple-knapsack problem and proposes a bat algorithm to optimize the solution. Experiments\nshow that the proposed algorithm is better than greedy and dynamic programming algorithm. The major\ncontribution of this paper is to model the SDN users� resource requests and apply bat algorithm for the solution....
Although relaying can be very beneficial for wireless systems, understanding which relaying schemes can achieve specific\r\nperformance objectives under realistic fading is crucial. In this paper we present a general framework for modeling and evaluating\r\nthe performance of dual-hop decode-and-forward (DF) relaying schemes over independent and not necessarily identically\r\ndistributed (INID) Nakagami-m fading channels.We obtain closed-form expressions for the statistics of the instantaneous output\r\nsignal-to-noise ratio of repetitive transmission with selection diversity. Furthermore, we present a unified statistical overview of\r\nother three significant relaying schemes with DF, one based on repetitive transmission with maximal-ratio diversity and the other\r\ntwo based on relay selection (RS). To compare the considered schemes, we present closed-form and analytical expressions for\r\nthe outage probability and the average symbol error probability under various modulation methods, respectively. Importantly,\r\nit is shown that when the channel state information for RS is perfect, RS-based schemes always outperform repetitive ones.\r\nFurthermore, when the direct link between the source and the destination nodes is sufficiently strong, relaying may not result\r\nin any gains, and it should be switched off....
Power line communications (PLCs) refer to a technology based on the existing electrical wiring to transmit data among the devices\nconnected to the network. The PLC technology is an excellent solution widely studied and analysed by researchers, even in those\nareas characterized by strict requirements, such as industries. In this paper, a technique based on fuzzy logic, for the dynamic\nmanagement of the amplitude of the signal emitted by the devices of a power line network, is proposed.Themain aim is to manage\nthe amplitude of the transmission signal in order to reduce the noise introduced into the network, and, as a consequence, the\npower consumption, increasing data transmission quality of network in terms of Quality of Service (QoS). This solution has been\nimplemented into embedded systems based on the ADD1010, a power line System on Chip (SoC), and tested through a real scenario\nrealized in laboratory....
Images get degraded because of unbalanced enlightenment including\ntext-smearing, ink-bleeding, degradation of ink over time, manuscript characters\nfrom background coming out and blended with the characters of the\nmain side etc. So, degraded-document enhancement is a challenging issue. In\nrecent years, several binarization approaches are proposed to enhance these\nimages. These techniques have focused on finding a suitable global threshold\nvalue or a local threshold value for every region to eliminate the degradations.\nA hybrid approach can be a good solution to deal with all these matters together.\nThis paper proposes a hybrid approach of binarization for degraded\ndocuments to produce better quality result........................
We introduce an improved image transmission scheme over wireless channels with flat Rayleigh fading. The proposed scheme\r\njointly optimizes bit power and modulation level to maximize the peak signal-to-noise ratio (PSNR) of the reconstructed image\r\nand hence improves the perceptual quality of the received image. In this optimization process, the significance of bits with regard to\r\nthe overall quality of the image is exploited. The optimality of the proposed algorithm is demonstrated using the Lagrange method\r\nand verified through an iterative offline exhaustive search algorithm. For practical implementation, a look-up table is used at the\r\ntransmitter for assigning the bit power and modulation level to each bit stream according to the received signal-to-noise ratio\r\n(SNR) observed at the receiver. The proposed scheme has low complexity since the look-up table is computed offline, only once,\r\nand used for any image which makes it suitable for devices with limited processing capability. Analytical and simulation results\r\nshow that the proposed scheme with jointly optimized bit power and variable modulation level provides an improvement in PSNR\r\nof about 10 to 20 dB over fixed power fixed modulation (16-QAM). A further reduction in complexity is achieved by using the\r\naverage signal-to-noise ratio rather than the instantaneous SNR in selecting the system parameters....
IEEE 802.15.4 is an important standard for Low Rate Wireless Personal Area Network (LRWPAN). The IEEE 802.15.4 presents a\nflexible MAC protocol that provides good efficiency for data transmission by adapting its parameters according to characteristics\nof different applications. In this research work, some restrictions of this standard are explained and an improvement of traffic\nefficiency by optimizing MAC layer is proposed. Implementation details for several blocks of communication system are carefully\nmodeled.The protocol implementation is done usingVHDL language.Theanalysis gives a full understanding of the behavior of the\nMAC protocol with regard to backoff delay, data loss probability, congestion probability, slot effectiveness, and traffic distribution\nfor terminals. Two ideas are proposed and tested to improve efficiency of CSMA/CA mechanism for IEEE 802.15.4 MAC Layer.\nPrimarily, we dynamically adjust the backoff exponent (BE) according to queue level of each node. Secondly, we vary the number of\nconsecutive clear channel assessment (CCA) for packet transmission.We demonstrate also that slot compensation provided by the\nenhanced MAC protocol can greatly avoid unused slots. The results show the significant improvements expected by our approach\namong the IEEE 802.15.4 MAC standards. Synthesis results show also hardware performances of our proposed architecture....
Low power wide area network (LoRaWAN) protocol has been widely used in various fields.\nWith its rapid development, security issues about the awareness and defense against malicious events\nin the Internet of Things must be taken seriously. Eavesdroppers can exploit the shortcomings\nof the specification and the limited consumption performance of devices to carry out security\nattacks such as replay attacks. In the process of the over-the-air-activation (OTAA) for LoRa\nnodes, attackers can modify the data because the data is transmitted in plain text. If the userâ??s\nroot key is leaked, the wireless sensor network will not be able to prevent malicious nodes from\njoining the network. To solve this security flaw in LoRaWAN, we propose a countermeasure called\nSecure-Packet-Transmission scheme (SPT) which works based on the LoRaWAN standard v1.1 to\nprevent replay attacks when an attacker has obtained the root key. The proposed scheme redefines\nthe format of join-request packet, add the new One Time Password (OTP) encrypted method and\nchanges the transmission strategy in OTAA between LoRa nodes and network server. The security\nevaluation by using the Burrows-Abadi-Needham logic (BAN Logic) and the Scyther shows that\nthe security goal can be achieved. This paper also conducts extensive experiments by simulations\nand a testbed to perform feasibility and performance analysis. All results demonstrate that SPT is\nlightweight, efficient and able to defend against malicious behavior....
LTE heterogeneous networks (HetNets) is becoming a popular topic since it\nwas first developed in 3GPP Release 10. HetNets has the advantage to assemble\nvarious cell networks and enhance users� Quality of Service (QoS) within\nthe system. However, its development is still constrained by two main issues:\n1) Load imbalance caused by different transmission powers for various tiers,\nand 2) The unbalanced transmission power may also increase unnecessary\nhandover rate. In order to solve the first issue, Cell range expansion (CRE)\ncan be applied in the system, which will benefit lower-tier cell during user association\nphase; CRE, Hysteresis Margin (HM) and Time-to-Trigger (TTT)\nwill be utilized to bound UE within lower tier network of HetNets and therefore\nsolve the second issue. On the other hand, the relationship of these parameters\nmay be complicated and even reduce QoS if they are chosen incorrectly.\nThis paper will evaluate the advantage and disadvantage of all three parameters\nand propose a Markov Chain Process (MCP) based method to find optimal\nHM, CRE and TTT values. And then, the simulation is taken and the\noptimal combination for our scenario is obtained to be 1 dB, 6 dB and 60 ms\nrespectively. First contribution of this paper is to map the HetNets handover\nprocess into MCP and all the phases of handover can be calculated and analysed\nin probability way, so that further prediction and simulation can be realised.\nSecond contribution is to establish a mathematical method to model the\nrelationship of HM, CRE and TTT in HetNets, therefore the coordination of\nthese three important parameters is achieved to obtain system optimization...
The Session Initiation Protocol (SIP) is an application layer signaling protocol used to create, manage, and terminate sessions in an\nIP based network. SIP is considered as a transactional protocol. There are two main SIP transactions, the INVITE transaction and\nthe non-INVITE transaction.The SIP INVITE transaction specification is described in an informal way in Request for Comments\n(RFC) 3261 and modified in RFC 6026. In this paper we focus on the INVITE transaction of SIP, over reliable and unreliable\ntransportmediums, which is used to initiate a session. In order to ensure the correctness of SIP, the INVITE transaction is modeled\nand verified using event-B method and its Rodin platform. The Event-B refinement concept allows an incremental development\nby defining the studied system at different levels of abstraction, and Rodin discharges almost all proof obligations at each level.\nThis interaction between modeling and proving reduces the complexity and helps in assuring that the INVITE transaction SIP\nspecification is correct, unambiguous, and easy to understand....
Nearest neighbor (NN) models play an important role in the intrusion detection system (IDS). However, with the advent of the era\nof big data, the NN model has the disadvantages of low efficiency, noise sensitivity, and high storage requirement. This paper\npresents a neighbor prototype selection method based on CCHPSO for intrusion detection. In the model, the prototype selection\nand feature weight adjustment are performed simultaneously and k-nearest neighbor (KNN) is used as the basic classifier. To deal\nwith large-scale optimization problems, a cooperative coevolving algorithm based on hybrid standard particle swarm and binary\nparticle swarm optimization, which employs the divide-and-conquer strategy, is proposed in this paper. Meanwhile, a fitness\nfunction based on the accuracy and data reduction rate is defined in the CCHPSO to obtain a set of appropriate prototypes and\nfeature weights. The KDD99 and NSL datasets are used to assess the effectiveness of the method. The empirical results indicate that\nthe data reduction rate of the proposed method is very high, ranging from 82.32% to 92.01%. Compared with all the data used, the\nproposed method can not only achieve comparable accuracy performance but also save a lot of storage and computing resources....
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