• 제목/요약/키워드: Visible light communications

Search Result 126, Processing Time 0.018 seconds

Technical problems of Li-Fi wireless network (무선 네트워크 기술 Li-Fi의 문제점)

  • Park, Hyun Uk;Kim, Hyun Ho;Lee, Hoon Jae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2014.10a
    • /
    • pp.186-188
    • /
    • 2014
  • In recent years, domestic as well as LTE wireless network of Wi-Fi and most used. In addition, mobile-intensive services that used mainly in our society makes it easier, SNS, application (APP), and file downloads. As such, the amount of data requested, while living at the time of mobile users will want to be safe from the earliest. And the wireless network communications mortality (3G, 4G (LTE), LTE-A) and Wi-Fi (802.11 n-2.4 G H z z H a c-5, 802.11 G), and users are mainly used in the death 4G (LTE), communication Wi-Fi, 802.11 n-2.4 GHz are used most frequently. As above, use the wireless network in order to safely and quickly developed the technology of the Li-Fi. Li-Fi light (visible light) technology to communicate with, and Wi-Fi (802.11 n-2.4 G z H) 100 times faster, LTE-A 66 times faster. However, the current Li-Fi to commercialise the big issue exists. In this paper, there are a lot of existing problems in the commercialization of Li-Fi being used in Wi-Fi, and a comparative analysis.

  • PDF

Characteristic of Transient Response in Nonuniform Instability with Optically Controlled Fiber (광학적으로 제어된 섬유를 가진 비균일 불안정성의 과도 응답의 특성)

  • Han, Pan-Lin;Park, Kwang-Chea
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
    • /
    • v.9 no.5
    • /
    • pp.445-450
    • /
    • 2016
  • In this paper we study the effect of chaos in nonuniform instability with optical fiber based IoT networks. The transient response of optically controlled fiber has also described. Nonlinear optical fiber effects especially fiber scattering in networks has emerged as the essential means active optical devices. The paradigm instability in fiber Internet serves as a test for fundamental study of chaos and its suppression and exploitation in practical application in optical communication. This paper attempts to present a survey and some of our research findings on the nature of chaotic effect on Internet based optical communication. The transient response in optical fiber has been evaluated theoretically by calculating the variation of the scattering function. The lines has used under open ended termination containing optically induced region. The scattered optical waves in a fiber used in optic communications are temporally unstable above certain threshold intensity.

Long Distance High Efficiency Transmission Techniques for Digital Signage (디지털 사이니지를 위한 장거리 고효율 전송 기법)

  • Lee, Sun Yui;Cha, Jae Sang;Jang, Yeong Min;Kim, Jin Young
    • Journal of Satellite, Information and Communications
    • /
    • v.10 no.1
    • /
    • pp.62-66
    • /
    • 2015
  • This paper introduces various applications and contents of digital signage, and analyzes conventional communication techniques to increase communication range. To realize digital signage in long distance, this paper proposes a hybrid modulation scheme and analyzes its performance. To verify its performance in real channel environment, we mapped symbols and experimented data transmission and reception with a visible light communication module with USRP. As a result, we confirmed a data receiving range and power of transmission and reception of the hybrid modulation mode. Also, we showed that the proposed modulation scheme has better performance of communication range and power efficiency than that of the conventional QAM technique.

Performance of Double Binary Turbo Coding for LED-ID Systems (LED-ID 시스템을 위한 이중 이진 터보 코딩의 성능)

  • Hwang, Yu-Min;Kim, Kyung-Ho;Kim, Jin-Young
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.38C no.11
    • /
    • pp.1078-1083
    • /
    • 2013
  • At the ubiquitous age, applications of Wireless Personal Area Network (WPAN) technology using LEDs are in progress. However, visible light communication using LED have weakness, which deteriorates performance of communication. To reduce information losses, which is caused by optical noise, such as incandescent lamps, fluorescent lamps, sunbeam etc., proposed channel coding scheme, double binary turbo codes. In this paper, encoding scheme of the proposed system is described and simulation results are analyzed. We had expected improved performance by using double binary turbo codes. Finally, performances of the proposed system came up to our expectations.

Queuing Analysis of IEEE 802.15.4 GTS Scheme for Bursty Traffic (Bursty Traffic을 위한 IEEE 802.15.4 GTS 기법의 대기 해석)

  • Le, Nam-Tuan;Choi, Sun-Woong;Jang, Yeong-Min
    • Journal of Satellite, Information and Communications
    • /
    • v.5 no.2
    • /
    • pp.87-91
    • /
    • 2010
  • The IEEE 802.15.4 and IEEE 802.15.7 standard are the typical of low rate wireless and Visible Light Wireless personal area networks. Its Medium Access Control protocol can support the QoS traffic flows for real-time application through guaranteed time slots (GTS) in beacon mode. However, how to achieve a best allocation scheme is not solved clearly. The current analytical models of IEEE 802.15.4 MAC reported in the literature have been mainly developed under the assumption of saturated traffic or non-bursty unsaturated traffic conditions. These assumptions don't capture the characteristics of bursty multimedia traffic. In this paper, we propose a new analytical model for GTS allocation with burst Markov modulated ON-OFF arrival traffic.

Additional location data transmission and Remote-controller App. Development using Smart Phone (스마트폰 기반 부가 위치 데이터 전송 및 Mobile 리모컨 App. 개발에 관한 연구)

  • Lee, JungHoon
    • Journal of Satellite, Information and Communications
    • /
    • v.8 no.2
    • /
    • pp.12-16
    • /
    • 2013
  • In this paper, we proceeded a study about the mobile software applications using smartphone technology. Firstly, we proposed a communication which a position data transmission technique using LED flashlight with built-in smartphone and we develop the application to perform a remote controller for beam-forming communication based on visible light associated with the position of Smartphone user. OOK modulation was applied for transmitting location data via LED backlight flash of smartphone and PD is used for detecting receiving light. In case of remote controller application which was controlled by WiFi IP-networking and it controls LED direction for beam-forming communication. These suggestion can be a good example for ubiquitous position recognition system using smart phone and software.