• Title/Summary/Keyword: wireless communication service

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Light ID and HMD-AR Based Interactive Exhibition Design for Jeonju Hanok Village Immersive 3D View (전주 한옥마을의 실감 3D View를 위한 Light ID 및 HMD-AR 기반 인터렉티브 전시 설계)

  • Min, Byung-Jun;Mariappan, Vinayagam;Cha, Jae-Sang;Kim, Dae-Young;Cho, Ju-Phil
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.11 no.4
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    • pp.414-420
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    • 2018
  • The digital convergence looking for new ways to engage visitors by superimposing virtual content on projection over the real world captured media contents. This paper propose the Light ID based interactive 3D immersive exhibition things view using HMD AR technology. This approach does not required to add any additional infrastructure to be built-in to enable service and uses the installed Lighting or displays devices in the exhibit area. In this approach, the Light ID can be used as a Location Identifier and communication medium to access the content unlike the QR Tag which supports provide the download information through web interface. This utilize the advantages of camera based optical wireless communication (OWC) to receive the media content on smart device to deliver immersive 3D content visualization using AR. The proposed exhibition method is emulated on GALAXY S8 smart phone and the visual performance is evaluated for Jeonju Hanok Village. The experimental results shows that the proposed method can give immersive 3D view for exhibit things in real-time.

Fading Effects and Antenna Diversity Tests of WAVE Communications (WAVE 통신의 페이딩 효과와 안테나 다이버시티 실험)

  • Choi, Hyun-Kyun;Oh, Hyun-Seo;Cho, Woong;Jang, Youn-Seon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39C no.10
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    • pp.967-973
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    • 2014
  • WAVE (Wireless Access in Vehicular Environments) communications is the core technology for C-ITS (Cooperative-Intelligent Transportation System) which communicates with the road infrastructure and other vehicles to exchange traffic information and service while driving. In this paper, to analyze the performance degradation according to the distance between WAVE communication terminals, we derived the formulas for the locations of down-fade and up-fade points by using the two-ray ground reflection model, and verified these theoretical results by comparing with those of RSSI (Receiver Signal Strength Indicator) measurements. In addition, to solve the problem of down-fade, we suggested the WAVE communication with the antenna diversity and experimentally confirmed the performance improvement in the highway LOS (Line Of Sight) environments.

Path Loss and Delay Characteristics According to Various Antennas at 2.45GHz in Subway Tunnel Environment (지하철 터널 환경에서 다양한 안테나에 따른 2.45GHz 대역의 경로손실 및 지연 특성)

  • Kong Min-Han;Park Noh-Joon;Kang Young-Jin;Song Moon-Kyou
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.5 s.347
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    • pp.162-168
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    • 2006
  • Understanding of propagation characteristics is very important for the wireless communication system design and wireless communication service construction. In this paper, propagation characteristics is measured and analyzed at 2.45Ghz frequency band under curved subway tunnel environment. We constituted channel measurement system with sliding correlation and five different kind of antennas. The purpose of five different type of antennas is to compare propagation characteristics according to beam shape of antennas. The path loss under tunnel environment is average $4.38^{\sim}14.41dB$ lower than free space and circular polarization antenna marked smallest path loss. Also, path loss is smallest when the receiver antenna located outside of tunnel in th curved section. 90% of delay components of all antennas measured within 20ns and directional antenna has more wide coherence bandwidth than omni-directional antenna. According to measured result, when we consider path loss and delay characteristics, circular polarization antenna is most suitable under tunnel environment.

Performance of Prioritized Service Discipline based on a Hop Count for Optical Burst Wireless Switched Networks (홉 기반의 우선처리를 고려한 광버스트 무선 교환방식의 성능분석)

  • Kim, Dong-Ok;Yoon, Hong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.1
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    • pp.34-39
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    • 2005
  • In this paper, we propose a new prioritized Optical Burst Switching (OBS) protocol based on a hop count, which can provide an efficient utilization in optical Wireless networks. Under several legacy schemes, a switch drops the burst with a shorter time among ones regardless of its traversed hop count. As a result, the dropped burst that have been traversed more hops might cause to waste bandwidth than the one traversed a few hops. Noting that this problem, we propose the Just Enough Time(JET) with a hop count scheme which can reduce the wasted bandwidth by prioritizing the burst traversed more hops over others. From the simulation result, we show that the proposed scheme is advantageous over the legacy schemes in terms of the burst blocking probability and the link utilization.

Frame Management Method to Support QoS of MAC Protocol Based TDMA in Mesh Network Environment (메쉬네트워크 환경에서 TDMA기반 MAC 프로토콜의 QoS를 지원하기 위한 프레임 관리기법)

  • Jang, In-Yong;Lee, Sun-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.6
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    • pp.75-87
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    • 2009
  • It is difficult to support QoS service in existing MAC Protocols in Wireless Mesh Network environments. while DCF can not support QoS, EDCA is operated with prioritized channel access method but can not give full performance. This thesis proposes frame management method to support QoS in Multi-Media DCF(MMDCF) MAC Protocol working in wireless mesh network. MMDCF uses ACH phase in TDMA frame to perform selection and elimination. Prioritized phases's count m and Fair Elimination phases's count n determine contention level and make string probability to only one win the contention. Forced TDMA Frame release method can support QoS requirements. MMDCF results good performance and good channel efficiency to support QoS requirements better than EDCA in multimedia stream environments.

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An Ad-hoc Routing Protocol for High-speed Multimedia Traffic Based on Path Quality and Bandwidth Estimation in Wireless Ad Hoc Networks (무선 애드혹 네트워크에서 경로 품질 및 잔여 대역폭 예측에 기반한 고속 멀티미디어 데이터 전송의 라우팅 프로토콜)

  • Shohel, Ahmed Md.;Yoon, Seokhoon
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.6
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    • pp.203-210
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    • 2013
  • Majority of the wireless ad hoc routing protocols are proposed to find feasible routes without considering the network load, end-to-end link quality and bandwidth requirements of the application. Therefore, protocol may not provide sufficient quality of service (QoS) to a high speed traffic such as multimedia. In this paper, we propose a path-quality and bandwidth-estimation based routing protocol (PBBR) for the high quality multimedia stream that can meet the application's bandwidth requirements and find the best reliable route. The novelty of this protocol is to select a reliable path to respond the application's requirements based on available bandwidth at each intermediate node and end-to-end path loss ratio. Obtained results from the simulation demonstrates that our protocol can achieve sufficient performance in terms of throughput and end-to-end delay.

Communication Protocol to Support Mobile Sinks by Multi-hop Clusters in Wireless Sensor Networks (무선 센서 네트워크에서 멀티-홉 클러스터를 통한 이동 싱크 지원 통신 프로토콜)

  • Oh, Seung-Min;Jung, Ju-Hyun;Lee, Jeong-Cheol;Park, Ho-Sung;Yim, Yong-Bin;Kim, Sang-Ha
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.3A
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    • pp.287-295
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    • 2010
  • In wireless sensor networks(WSNs), the studies that support sink mobility without global position information exploit a Backbone-based Virtual Infrastructure (BVI) which considers one-hop clusters and a backbone-based tree. Since the clusters of a sink and a source node are connected via flooding into the infrastructure, it causes high routing cost. Although the network could reduce the number of clusters via multi-level clusters, if the source nodes exist at nearest clusters from the cluster attached by the sink and they are in different branches of the tree, the data should be delivered via detour paths on the tree. Therefore, to reduce the number of clusters, we propose a novel multi-hop cluster based communication protocol supporting sink mobility without global position information. We exploit a rendezvous cluster head for sink location service and data dissemination but the proposed protocol effectively reduces data detour via comparing cluster hops from the source. Simulation shows that the proposed protocol is superior to the existing protocols in terms of the data delivery hop counts.

The wireless CDMA ALOHA System Concept for the Voice/Data Integrated Transmission and Its traffic Analysis (음성/데이터 통합 전송을 위한 무선 CDMA ALOHA 시스템 구상과 그 트래픽 분석)

  • Kwon, Ki-Hyung
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2010.07a
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    • pp.173-179
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    • 2010
  • Currently, the communication systems are progressing two ways as the wireless and multimedia and these need big transmission capacity then before. In these circumstance, communication services existed as two different service forms which have different rates and characteristics. For example Voice/Video Services accept some errors but transmit on realtime, but Date Services don't need to transmit on realtime but have to retransmit if these have only one bit error. In Voice/Date Integrated traffics, it has big throughput that realtime voice/video data which could have some errors if integrated traffic is increased rapidly have transmission priority, then Data traffics which delay is accepted is sent after that. In this paper, I introduce the calculation method for various traffic when voice/data mixed traffics is transmitted to asynchronous unslotted ALOHA CDMA system proposed and the result is presented. And We can easily theoretical analysis for the system traffic and changing traffic using proposed solution in this paper.

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Study of Optimum Parameters for Improving QoS in Wireless LAN (무선랜 QoS의 성능향상을 위한 최적 파라미터에 관한 연구)

  • Jin, Hyunjoon
    • Journal of IKEEE
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    • v.17 no.2
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    • pp.96-103
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    • 2013
  • Since multimedia data takes large part of realtime transmission in wireless communication environments such as IEEE 802.11, QoS issues became one of the important problems with network performance. 802.11e MAC provides differentiated services based on priority schemes to solve existing 802.11 MAC problems. The TXOP is an important factor with the priority to improve network performance and QoS because it defines the time duration in which multiple frames can be transferred at one time for each station. In this paper, therefore frame sizes, TXOP Limit, and Priority values in accordance with the number of stations are experimented and derived for best network performance and QoS. Using 802.11e standard parameters, simulation results show the best throughput when the number of stations is 5 and TXOP Limit value is 6.016ms. For fairness, the best result is achieved at 3.008ms of TXOP Limit value and 15-31 of CW(Contention Window) that is lower priority than CW 7-15.

IP-Based Heterogeneous Network Interface Gateway for IoT Big Data Collection (IoT 빅데이터 수집을 위한 IP기반 이기종 네트워크 인터페이스 연동 게이트웨이)

  • Kang, Jiheon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.23 no.2
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    • pp.173-178
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    • 2019
  • Recently, the types and amount of data generated, collected, and measured in IoT such as smart home, security, and factory are increasing. The technologies for IoT service include sensor devices to measure desired data, embedded software to control the devices such as signal processing, wireless network protocol to transmit and receive the measured data, and big data and AI-based analysis. In this paper, we focused on developing a gateway for interfacing heterogeneous sensor network protocols that are used in various IoT devices and propose a heterogeneous network interface IoT gateway. We utilized a OpenWrt-based wireless routers and used 6LoWAN stack for IP-based communication via BLE and IEEE 802.15.4 adapters. We developed a software to convert Z-Wave and LoRa packets into IP packet using our Python-based middleware. We expect the IoT gateway to be used as an effective device for collecting IoT big data.