• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.3
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• pp.482-488
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• 2009

Mobile Ad-hoc Networks provide communication without a centralized infrastructure, which makes them suitable for communication in disaster areas or when quick deployment is needed. On the other hand, they are susceptible to malicious exploitation and have to face different challenges at different layers due to its open Ad-hoc network structure which lacks previous security measures. Denial of service (DoS) attack is one that interferes with the radio transmission channel causing a jamming attack. In this kind of attack, an attacker emits a signal that interrupts the energy of the packets causing many errors in the packet currently being transmitted. In harsh environments where there is constant traffic, a jamming attack causes serious problems; therefore measures to prevent these types of attacks are required. The objective of this paper is to carry out the simulation of the jamming attack on the nodes and determine the DoS attacks in OPNET so as to obtain better results. We have used effective anomaly detection system to detect the malicious behaviour of the jammer node and analyzed the results that deny channel access by jamming in the mobile Ad-hoc networks.

• The Magazine of the IEIE
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• v.15 no.1
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• pp.57-64
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• 1988

이 글에서는 통신 전자전의 ESM과 ECM에 대한 일반적인 내용보다는, 그 중 한 특수 분야로서 전술 및 전략적으로 매우 큰 비중을 차지하고 있는 전파방향 탐지 및 방해기법을 위주로 하여 운용면 보다는 기술적 이론을 보안에 저촉되지 않는 한도내에서 상세히 설명하였다. 전파 방향 탐지 기법에 대해서는 주요 기법들의 분류 및 설명, 장비 구성방법을 비롯하여 이를 운용하며 방위각을 구하고 자동망에 의하여 위치표정을 하기까지의 주요 사항들을 항목별로 정리하였으며, 전파 방해 기법에 대해서는 기법별 특성에 대한 간략한 비교, 장비 구성방법과 필수 핵심부에 대한 분석 등을 수록하므로써 전파 방향 탐지 및 방해 기법의 전반에 걸친 내용을 다루었다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.20 no.3
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• pp.52-60
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• 1983

This paper presents a complete analysis for the derivation of the probability of error for a fast (or multiple-hops per bit) frequency hopping spread spectrum system employing binary FSK modulation and noncoherent reception in the presence of partial-band noise jamming and thermal noise. The worst-case error rate performances were obtained numerically and presented as a function of E /N with L as a parameter, where E /N and L are the signal bit energy-to-jamiming density ratio and the number of hops per bit, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4C
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• pp.453-459
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• 2009

Due to its capability to resist jamming signals, chirp spread spectrum (CSS) technique has attracted much attention in the field of wireless communications. However, there has been little rigorous analysis for the performance of CSS systems in the presence of jamming signals. In this paper, thus, we present analytic results on the performance of a CSS system: specifically, symbol error rate (SER) expressions are derived for a CSS M-ary phase shift keying (MPSK) system in the presence of broadband and tone jamming signals, respectively. The numerical results show that the empirical SER closely agree with the analytic result.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.12 s.354
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• pp.24-30
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• 2006

This paper considers interference suppression and multipath mitigation in Global Navigation Satellite Systems (GNSSs). We propose an anti-jam GNSS receiver which suppresses interference and multipath by subspace projection method. The resulting interference suppressed and multipath mitigated signal is then process by a beamformer, whose weight vector maximizes the signal-to-noise ratio of the output signal. The enhanced performance is shown by refined cross correlation and beam pattern.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.5C
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• pp.444-452
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• 2012

The detection performances, in this paper, are derived according to combination of the multiband GNSS signals in broadband jamming environments. The detection probabilities depending on the false alarm probabilities are derived and presented via Monte-Carlo simulation under the assumption as follows: the GNSS signals are perfectly orthogonal and simultaneously received by the receiver using non-coherent correlation.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.07a
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• pp.371-372
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• 2012

본 논문은 협력 네트워크(cooperative network)에서 무선 채널의 보안성(security) 강화를 위한 자가 전파방해(self-jamming) 기반 기회적 중계(opportunistic relaying) 기법을 제안한다. 단일 송신 단말 (source)과 단일 수신 단말(destination)이 다중 중계 단말(relay)의 협력을 통해 송수신하는 이중 홉(dualhop) 네트워크에서 도청 단말(eavesdropper)에 의한 정보 절취를 최소화하기 위해 자가 전파방해 기법과 기회적 중계 기법을 결합한다. 이를 통해 무선 채널의 방송(broadcasting) 특성에 기인한 도청 용이성을 저하 시키고, 다중 중계 단말의 송신 전력을 최소화하여 협력 네트워크의 수명(lifetime)을 연장한다. 컴퓨터 모의실험 결과를 통해 제안된 기법이 다중 중계기가 있는 이중 홉 협력 네트워크에서 보안 전송률(secrecy rate)의 불능확률(outage probability) 성능을 제고함을 보인다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.8
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• pp.859-867
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• 2016

The Global Positioning System is a navigation system that has been developed by the United States for military use. Currently, many countries, including the Republic of Korea, use GPS for civilian and military uses. However, as useful as it is, GPS is vulnerable to its Jamming signal, as the strength of the signal from satellites is very weak. In this paper, a novel jamming signal detection and cancellation method is proposed when a narrow-band jamming signal is included in the GPS received signal. At the GPS receiver, the received signal is transformed to a frequency domain sample by Fast Fourier Transform. In order to suppress the Spectral Leakage, the Blackman-Harris window is used. The proposed jamming signal cancellation algorithm will find the frequency sample with maximum power and null the maximum sample in addition to some lateral samples. If the GPS receiver is designed with FFT of size 128 to 512, it is shown that 42 samples are optimal to cancel the narrow-band jamming signal.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.12
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• pp.2279-2284
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• 2017

Recent wireless communications using the unlicensed band have been on the rise and the range of use is increasing. The license-exempted band is a prerequisite for accepting interference between telecommunication equipment. In particular, the interference phenomenon of Bluetooth, wireless LAN, and RFID (Radio Frequency Identification) using the 2.4 GHz band is getting serious. In such urban areas, the wireless transmission medium may be in a bad state. There are roughly two ways to make effective transmission in this environment. The first is the IEEE 802.11 RTS / CTS method and the second is the frame fragmentation method. In this paper, it is difficult to transmit a frame over a certain size in a jamming environment due to the interference of the wireless environment. In this environment, we implement a frame division transmission scheme that guarantees effective transmission and reliability by dividing a frame into smaller units in order to perform reliability transmission and efficient transmission.

• Journal of Advanced Navigation Technology
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• v.15 no.5
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• pp.714-721
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• 2011

In this paper, developing management programs for EMI tracking can navigate the site quickly and solve EMI tracking cause and location to use materials such as analysis of air accidents, EMI site location data of 1000 RF companys, radio wave spectrum analysis and audio data. these data are databased and used comparable data. Also, EMI has been prevented by establishing continuous monitoring system through a 24-hour surveillance. Therefore we were able to provide high quality air waves in order to prevent aircraft accidents. In addition, radar control staff of Korea Airports Corporation against passenger aircraft that will prevent the worst aircraft accident have been established based to continue periodic aviation frequency protection and Portable Electronic Devices(PED) on board aircraft to prevent the culture of safety campaign.