무선 센서 네트워크 채널 분석

정경권(Kyung Kwon Jung),최우승(Woo-Seung Choi) 한국컴퓨터정보학회 2008 韓國컴퓨터情報學會論文誌 Vol.13 No.5

무선 센서 네트워크의 응용범위가 늘어남에 따라 정확한 무선 채널의 정보를 필요로 한다. 실내 또는 실외의 무선 센서 네트워크의 경우 페이딩에 의한 다중 경로 전파가 문제를 일으키고 있다. 본 논문에서는 실내 2.4 ㎓ 채널에 대한 log-normal path loss 모델링을 살펴본다. 송신기와 수신기 사이의 거리를 1에서 30 m까지 변화시키면서 수신 신호 강도 변화를 측정하고, 채널의 감쇄지수와 표준편차를 계산하였다. 계산한 모델의 패킷 수신율을 이용하여 무선 센서 채널을 연결 영역과 차단 영역으로 정의하고, 시뮬레이션과 실험 결과를 통해서 무선 채널의 특징을 비교하였다. 실험결과 실내에서의 연결 영역은 24 m, 실외에서의 연결 영역은 14 m로 측정되었다. In proportion as the growth of the wireless sensor network applications, we need for more accuracy wireless channel information. In the case of indoor or outdoor wireless sensor networks, multipath propagation causes severe problems in terms of fading. Therefore, a path-loss model for multipath environment is required to optimize communication systems. This paper deals with log-normal path loss modeling of the indoor 2.4 ㎓ channel. We measured variation of the received signal strength between the sender and receiver of which separation was increased from 1 to 30 m. The path-loss exponent and the standard deviation of wireless channel were determined by fitting of the measured data. By using the PRR(Packet Reception Rate) of this model. Wireless sensor channel is defined CR (Connect Region), DR(Disconnected Region). In order to verify the characteristics of wireless channel, we performed simulations and experiments. We demonstrated that connection ranges are 24 m in indoor, and 14 m in outdoor.

Develop an Effective Security Model to Protect Wireless Network

Ataelmanan, Somya Khidir Mohmmed,Ali, Mostafa Ahmed Hassan International Journal of Computer ScienceNetwork S 2021 International journal of computer science and netw Vol.21 No.3

Security is an important issue for wireless communications and poses many challenges. Most security schemes have been applied to the upper layers of communications networks. Since in a typical wireless communication, transmission of data is over the air, third party receiver(s) may have easy access to the transmitted data. This work examines a new security technique at the physical layer for the sake of enhancing the protection of wireless communications against eavesdroppers. We examine the issue of secret communication through Rayleigh fading channel in the presence of an eavesdropper in which the transmitter knows the channel state information of both the main and eavesdropper channel. Then, we analyze the capacity of the main channel and eavesdropper channel we also analyze for the symbol error rate of the main channel, and the outage probability is obtained for the main transmission. This work elucidate that the proposed security technique can safely complement other Security approaches implemented in the upper layers of the communication network. Lastly, we implement the results in Mat lab

A Wireless Channel Simulation Method Using Doppler Spectrum Models

Lee, Jong-Gil The Korea Institute of Information and Commucation 2003 한국정보통신학회논문지 Vol.7 No.3

다양한 이동통신 채널의 모의구현은 시스템 구현 및 검증에 매우 중요한 요소이다. 따라서 본 논문에서는 이동통신 채널을 효율적으로 모의할수 있는 방법을 제안하였다. 새롭게 제안된 방법은 주어진 도플러 스펙트럼 모델로부터 협대역 이동통신 채널의 발생을 가능하게 함으로서 신호대 잡음비, 직접 및 간접 전파경로, 신호전력등의 다양한 전파환경을 고려한 채널의 구현이 가능하다. It is very important to simulate various mobile communication channels for the reliable system design and performance tests. Therefore, a new method is proposed in this paper to improve the conventional one for the purpose of the efficient channel simulation having various characteristics. A newly proposed method can simulate any narrow band channel very efficiently from the given Doppler power spectrum model. Also, it has many simulation advantages considering the variety of wireless channel conditions since parameters related with channel characteristics, such as a signal power, signal to noise ratio, direct signal power ratio, etc., can be easily changed according to various propagation environments to be tested.

Novel Approach for Modeling Wireless Fading Channels Using a Finite State Markov Chain

Ahmed Abdul Salam,Ray Sheriff,Saleh Al-Araji,Kahtan Mezher,Qassim Nasir 한국전자통신연구원 2017 ETRI Journal Vol.39 No.5

Empirical modeling of wireless fading channels using common schemes such as autoregression and the finite state Markov chain (FSMC) is investigated. The conceptual background of both channel structures and the establishment of their mutual dependence in a confined manner are presented. The novel contribution lies in the proposal of a new approach for deriving the state transition probabilities borrowed from economic disciplines, which has not been studied so far with respect to the modeling of FSMC wireless fading channels. The proposed approach is based on equal portioning of the received signal-to-noise ratio, realized by using an alternative probability construction that was initially highlighted by Tauchen. The associated statistical procedure shows that a first-order FSMC with a limited number of channel states can satisfactorily approximate fading. The computational overheads of the proposed technique are analyzed and proven to be less demanding compared to the conventional FSMC approach based on the level crossing rate. Simulations confirm the analytical results and promising performance of the new channel model based on the Tauchen approach without extra complexity costs.

cdma2000 통신망에서 적응적인 멀티미디어 서비스를 위한 패킷 손실 모델링

서원범,박성희,서덕영,신지태,Suh Won-Bum,Park Sung-Hee,Suh Doug-Young,Shin Ji-Tae 한국통신학회 2004 韓國通信學會論文誌 Vol.29 No.1B

한국에서 서비스 중인 cdma2000 1x 인터넷 데이터 서비스의 패킷 손실 패턴을 두개의 상태를 가진 길버트 모델로 모델링 한다. 본 논문에서는 한국의 주요 서비스 업체의 cdma2000 1x 서비스를 사용하여 측정된 패킷 손실트레이스(trace)로 부터 길버트 모델의 관련변수를 얻는 방법을 제안한다. 건물의 밀도가 크게 높지 않은 지역에서 건물 안에서 고정된 위치와 차로 이동하는 상황에서 관련변수를 얻을 수 있었다. 이 정보는 무선망의 채널 정보를 연구하기 위한 패킷 손실 패턴을 만들기 위해서 사용될 수 있다. 본 논문에서는 cdmla2000 1x 망에서 실제 측정을 통하여 실시간 멀티미디어 서비스를 하기 위해 요구되는 005에 관하여 논의한다. 이것을 위해서 망의 정보를 주는 패킷 측정 툴을 개발하였고 멀티미디어 서비스를 위한 005정보를 제공하며, 측정된 데이터를 사용하여 서비스의 품질 유지에서 요구되는 채널의 상태 판별법을 길버트 모델을 사용하여 제안하였다. 채널모델의 파라메터를 실시간(on-line)으로 구할 수 있다면 네트웍의 상황에 적응적인 손실 보호 제어를 적절히 선택하여 사용될 수 있다. Packet loss process of cdma2000 mobile Internet channel deployed in Korea is modeled as a two state Markov process known as Gilbert model. This paper proposes the procedures to derive four parameters of the our modified Gilbert model from packet loss trace taken from two major cdma2000 networks in Korea. These four parameters are derived in various situations, that is, with fixed and moving terminals, in open field and urban areas. They can be used to produce synthetic packet loss patterns for study of the channel. Moreover, if they are calculated on-line during multimedia service, they can be used to make loss protection controls adaptive to network condition.

Performance Analysis of Adaptive Frame Size Control Scheme in Wireless Networks

김응인(Eung In Kim) 大韓電子工學會 2010 電子工學會論文誌 IE (Industry electronics) Vol.47 No.2

본 논문은 무선 데이터 네트워크에 적용 가능한 적응 프레임 길이 제어 방식을 가진 데이터 링크 프로토콜을 제안한다. 무선 데이터망은 수시로 변화는 에러 환경에 놓여 있다. 이런 에러 환경에서도 잘 적용할 수 있는 가변 프레임 제어 방식을 제안하고 그 성능을 분석하였다. 2상태 마코프 모델을 이용하여 채널 환경을 모델링하였다. 수치해석방식을 통하여 새롭게 제안한 방식이 다양한 종류의 에러환경에서도 좋은 성능을 발휘할 수 있음을 보여 주었다. This paper suggests a new data link protocol with an adaptive frame length control scheme for wireless data networks which is subject to errors that occur with time variance. We analyze the proposed scheme under a two-state markov block interference(BI) model. Numerical results show that the proposed scheme can achieve high throughput performance for both dense and diffuse burst noise channels.

Survey on Empirical Channel Models for WBAN

Sukhraj Kaur,Dr. Jyoteesh Malhotra 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.2

Wireless body area networks (WBAN) are expected to be a breakthrough technology in healthcare areas, telemedicine, and physical rehabilitation. The nature of the propagation of electromagnetic signals in complex shaped human body in the case of WBAN is expected to be very much different from that found in other environments, e.g. home, offices, streets, etc. So in order to design a high quality WBAN it is very important to examine and improve the propagation characteristics of channel models of WBAN. The aim of this paper is to provide an overview of different channel models of WBANs. The effect of channel behavior due to dynamics has been surveyed and challenges in channel modeling have been extracted.

WBAN 채널 모델의 검토

강희조(Heau-Jo Kang) 한국정보기술학회 2010 Proceedings of KIIT Conference Vol.2010 No.-

유비쿼터스 네트워크를 지원하는데 있어서 무선 통신 네트워킹 기술은 중요한 역할을 하고 있다. Wireless Body Area Network(WEAN)은 IT-BT一NT 융합의 대표적인 기술로서 사람에게 보다 향상된 품질과 편의를 제공한다. 본 논문에서는 WEAN 채널 모델과 사용주파수 대역을 검토하고자 한다. Wireless communication networking technology plays an important part in supporting ubiquitous network. IT, BT and NT convergence of typical techniques for Wireless body area network (WBAN) provides the quality and convenience. In this paper, we study on the WBAN channel model and use frequency band.

Classification of Turbulence Channels Using Convolutional Neural Network (CNN) for 4-PSK Optical Wireless Communication (OWC) System

Yongwoon Hwang,Chung Ghiu Lee 한국차세대컴퓨팅학회 2023 한국차세대컴퓨팅학회 학술대회 Vol.2023 No.12

In outdoor optical wireless communication systems, weather-induced turbulence affects optical signals, resulting in distortion, thereby, degradation in communication performance. The channel model including turbulence is used for estimating the performance of optical wireless communication system under turbulence. A deep learning algorithm is developed to classify degree of turbulence. This study is based on channel classification using a convolutional neural network for a 4-PSK optical wireless communication system. The channel characteristics are generated following the gamma-gamma distribution. By labeling each data point and distorted constellation for different degrees of turbulence, the deep learning model is trained, and its classification performance is evaluated.

OPTIMIZATION OF THE RAYLEIGH FADING CHANNEL MODEL IN MOBILE ENVIRONMENT

Injae Won,Changhee Kim,Youngju Kim,Keehyun Lee 한국멀티미디어학회 2006 한국멀티미디어학회 국제학술대회 Vol.2006 No.-

Clarke's fading channel model is very simple simulator based on the SOS (Sum-Of-Sinusoids) and has been widely used. However, it has some shortcomings. Its time correlation properties based on the simulated waveform do not correspond to the statistical ones. In this paper, the difference between statistical and time properties of Clarke's fading channel model is examined and new simulator is proposed.