Current Issue : October - December Volume : 2019 Issue Number : 4 Articles : 5 Articles
This paper presents an experimental study of a multihop Internet Protocol Version 6 over Low-Power Wireless Personal\nArea Networks (6LoWPAN)-based mesh system that uses un-slotted channel hopping (USCH) medium access control\n(MAC). Designers of wireless smart-grid networks are using (or looking to use) the Sub-1 GHz spectrum, given its longer\nradio range compared to the traditional 2.4 GHz spectrum used in Wi-Fi..........................
The need to achieve energy efficiency in machine-to-machine (M2M) communications has been a driver of the use of coalition\ngame-based cooperative communication schemes. The proposed schemes have shown good energy -efficient performance results\nin the recent past. However, sustaining cooperation amongst coalition games of M2M devices from different network-operating\nauthorities requires appropriate incentives. A review of the literature demonstrates that a limited number of contributions have\nconsidered the use of coalition games with incentives in M2M communications. In this paper, an energy-efficient coalition game\nwith incentives in M2M communications is proposed. This work considers a Sierpinski triangle technique to partition M2M\ndevices into multiple networks of hierarchical zones. Based on the constructed zones, a contract-modelled incentive is invoked to\nstimulate multihop transmissions between devices up to the BS/sink. The results obtained demonstrate that the proposed\napproach is on average 10% more energy efficient than the closely related existing algorithm, the coalition game theoretical\nclustering (CGTC)....
In this article, a method to enhance data rates of free-space optical (FSO) systems using packet length optimization is proposed.\nThe average signal-to-noise ratio (ASNR) is measured at the receiver and sent back to the transmitter to optimize packet length. In\naddition, the length of packet is optimized to enhance the average throughput. We concluded that packet length can be reduced at\nlow ASNR. However, packet length should be increased at higher values of received ASNR. For each ASNR, we also choose the\noptimal modulation and coding scheme (MCS) and optimal packet length to maximize the throughput. Different MCSs are\ninvestigated such as 4-pulse amplitude modulation (PAM) with and without channel coding, 8-PAM, 16-PAM, and 32-PAM. The\nproposed method gives 0.8-1.9 dB gain with respect to conventional FSO with adaptive modulation and coding (AMC) and fixed\npacket length. This is the first paper to deal with packet length optimization for FSO systems....
Botnets are a common and serious threat to the Internet. The search for the infected nodes\nof a P2P botnet is affected by the number of commonly connected nodes, with a lower detection\naccuracy rate for cases with fewer commonly connected nodes. However, this paper calculates the\nMahalanobis distance-which can express correlations between data-between indirectly connected\nnodes through traffic with commonly connected nodes, and establishes a relationship evaluation\nmodel among nodes. An iterative algorithm is used to obtain the correlation coefficient between the\nnodes, and the threshold is set to detect P2P botnets. The experimental results show that this method\ncan effectively detect P2P botnets with an accuracy of >85% when the correlation coefficient is high,\neven in cases with fewer commonly connected nodes....
In this paper, the effect of time synchronization error on protection algorithms are studied\nfor the usage of the LAN-based collaborative protection. In order to derive the effect of time\nsynchronization, this paper proposes a substation model which is constructed with IEEE 1588\nPrecision Time Protocol (PTP) supported intelligent electronic devices. The proposed model is used\nas an example of a target platform to study the effect of time synchronization error with two typical\nsubstation protection algorithms, i.e., current differential-based substation protection and distance\nprotection algorithms. From the analyzed and the simulated results, it was well observed that time\nsynchronization error is a significant error-causing factor for both protection algorithms, resulting in\nerroneous detection of faults and erroneous estimation of fault distances, respectively. The results of\nresearch performed in this paper are expected to provide a good guide for constructing the future\nLAN-based digital power substation with precise time synchronization....
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