• Title/Summary/Keyword: wireless communication service

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Analysis of Global Trends and Issues of Cognitive Radio (Cognitive Radio 연구의 국내외 동향과 이슈 분석)

  • Moon, Sangook
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.10a
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    • pp.969-972
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    • 2009
  • With the advent of the era of ubiquitous computing, the number of wireless communication devices has been exponentially increasing, which phenomenon requires for the preparation for the upcoming shortage of frequency resource. Recently, in consequence, the concept of Cognitive Radio (CR) was introduced in which the wireless nodes periodically recognize and learn the external conditions of communication including the usage of the frequency spectrum. It is essential to assure sufficient range of frequency to satisfy the users of the increasing wireless network devices. However, since not only the frequency band for wireless communication is finite, but most part of them had already been assigned for the primary users of the wireless network service, it is very difficult to ensure the band of frequency for additional communication service. In this contribution, we analyze and describe the issues of designing and implementation of CR networks.

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A Measurement-based Quality Evaluation Scheme for Mobile VoIP Service over Wireless Broadband (WiBro) Networks (와이브로를 통한 모바일 VoIP 서비스의 측정 기반 품질 평가 방안)

  • Kim, Dong-Yon;Kim, Beom-Joon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.5 no.5
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    • pp.528-533
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    • 2010
  • Currently the telephone service using Internet grows and the recent introduction of a smart phone is expected to accelerate the trend. In particular, considering the domestic situation that the wireless broadband (WiBro) system deployed over the nation, the telephone service over WiBro can be a solution toward its fast expansion. Unlike telephone service over a conventional telephone network or mobile network, however, internet telephone cannot guarantee it service quality, which can be severer in a wireless environment such as a WiBro network. Therefore, a more strict and systematic management for controlling the quality of internet telephone service over WiBro in a more efficient way. As the first step to establish the management system, this paper proposes a scheme to manage the quality of internet telephone service over WiBro and introduces a software developed for the purpose. The developed software is installed on a user terminal and facilitates efficient service quality management by measuring the quality of internet telephone service over WiBro in terms of VoIP metric, network metric, and wireless metric.

A Study on IMT-2000 Moving Picture Messaging Service (IMT-2000 동영상 메시징 서비스에 관한 연구)

  • Kang, Ki-Joung
    • Annual Conference of KIPS
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    • 2000.10b
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    • pp.1051-1054
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    • 2000
  • IMT-2000 moving picture messaging service is a primary auxiliary connection service that allows a caller to leave a message when the caller can not complete the call. As the number of service subscriber for wireless communication is dramatically increased, various wireless services as well as simple connection service are requried IMT-2000 moving picture messaging service increases the call completion rate and makes it possible to provide various services.

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The case study on wireless lan design technique for Bansong purification plant using network integrated management system and security switch (네트워크 통합관리시스템과 보안스위치를 이용한 반송정수장 무선랜 구축사례)

  • Park, Eunchul;Choi, Hyunju
    • Journal of Korean Society of Water and Wastewater
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    • v.32 no.4
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    • pp.309-315
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    • 2018
  • Currently, the commercialization of the $5^{th}$ Generation (5G) service is becoming more prevalent in domestic communication network technology. This has reduced communication delay time and enabled large-capacity data transmission and video streaming services in real-time. In order to keep pace with these developments, K-water has introduced a smart process control system in water purification plants to monitor the status of the water purification process. However, since wireless networks are based on the public Long Term Evolution (LTE) network, communication delay time remains high, and high-resolution video services are limited. This is because communication networks still have a closed structure due to expense and security issues. Therefore, with 5G in its current form, it is very difficult to accommodate future services without improving the infrastructure of its communication networks. In recognition of these problems, this study implemented the authentication and management function of wireless networks on a wired network management system in the K-water Bansong water purification plant. The results confirmed that wired Local Area Network (LAN) services give a higher security performance than an expensive commercial wireless LAN system. This was achieved by using an Internet Protocol (IP) address management system of wired networks and the packet filtering function of the Layer2 (L2) switch. This study also confirmed that it is possible to create a wireless LAN service that is 3.7 times faster than the existing LTE communication network.

The Study of Building Security-Established Enterprise Mobile-VPN on WiBro Network (WiBro망에서 보안성이 확립된 기업용 Mobile-VPN 구축 방안 연구)

  • Cho, Do-Hyeoun;Kang, Dae-Seok;Han, Kyu-Jeong;Ji, Yung-Ha;Han, Wan-Ok
    • 전자공학회논문지 IE
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    • v.47 no.4
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    • pp.48-52
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    • 2010
  • Recently, WiBro service as a mobile internet has been being extended. The market of wireless data communication has been being extended rapidly due to the increase of mobile data communication service supply such as smart-phone, WiBro service and so on. As the result, security is also emphasized in the mobile Internet In this paper, we propose the methods that tighten up security in the upcoming Enterprise Mobile-VPN service on WiBro network.

Channel Coding-Aided Multi-Hop Transmission for Throughput Enhancement

  • Hwang, Inchul;Wang, Hanho
    • International Journal of Contents
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    • v.12 no.1
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    • pp.65-69
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    • 2016
  • Wireless communication chipsets have fixed transmission rate and communication distance. Although there are many kinds of chipsets with throughput and distance purpose, they cannot support various types of wireless applications. This paper provides theoretic research results in order to support various wireless applications requiring different throughput, delayed quality-of-service (QoS), and different communication distances by using a wireless communication chipset with fixed rate and transmission power. As a performance metric, the probability for a data frame that successfully receives at a desired receiver is adopted. Based on this probability, the average number of transmission in order to make a successful frame transmission is derived. Equations are utilized to analyze the performance of a single-hop with channel coding and a dual-hop without error correction matter transmission system. Our results revealed that single-hop transmission assisted by channel coding could extend its communication distance. However, communication range extending effect of the single-hop system was limited. Accordingly, dual-hop transmission is needed to overcome the communication distance limit of a chipset.

Full-Duplex Operations in Wireless Powered Communication Networks

  • Ju, Hyungsik;Lee, Yuro;Kim, Tae-Joong
    • ETRI Journal
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    • v.39 no.6
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    • pp.794-802
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    • 2017
  • In this paper, a wireless powered communication network (WPCN) consisting of a hybrid access point (H-AP) and multiple user equipment (UE), all of which operate in full-duplex (FD), is described. We first propose a transceiver structure that enables FD operation of each UE to simultaneously receive energy in the downlink (DL) and transmit information in the uplink (UL). We then provide an energy usage model in the proposed UE transceiver that accounts for the energy leakage from the transmit chain to the receive chain. It is shown that the throughput of an FD WPCN using the proposed FD UE (FD-WPCN-FD) can be maximized by optimal allocation of the UL transmission time to the UE by solving a convex optimization problem. Simulation results reveal that the use of the proposed FD UE efficiently improves the throughput of a WPCN with a practical self-interference cancellation capability at the H-AP. Compared to the WPCN with FD H-AP and half-duplex (HD) UE, FD-WPCN-FD achieved an 18% throughput gain. In addition, the throughput of FD-WPCN-FD was shown to be 25% greater than that of WPCN in which an H-AP and UE operated in HD.

Implementation of a High Performance Notch Filter Algorithm for Power Line Communication System (전력선 통신 시스템을 위한 고성능 Notch Filter 알고리즘 구현)

  • Nam, Yun-Ho;Jang, Dong-Won;Kim, Kyung-Seok
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.3
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    • pp.159-166
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    • 2010
  • As Power Line has been already installed over 60% of a residential area all over the world, Broadband Service has been possible using high-speed PLC(Power Line Communication) without new access line installed for Internet access. Because of such reason, PLC is researched as the most suitable service for Last Mile Solution. But, Power Line is designed for transmitting electric power, so peripheral Wireless Communication System is affected by a leak of electric wave. In this paper, we propose a High Performance Notch Filter algorithm in comparison with a existing notch filter for reduction of interference between existing Wireless Communication Service and Power Line Service. In addition, we implement the Notch Filter emulator appling a High Performance Notch Filter and using a embedded board.

A study on the VN number and LMS based connectionless services mobility in wireless ATM netwroks (W-ATM 망에서 VN번호 및 LMS을 기반으로 한 비연결형 서비스의 이동성 제공방법)

  • 한치문;박원기
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.9A
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    • pp.2230-2239
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    • 1998
  • Recently, mobility support of connectionless mobile ATM data service has been mainly studied in wireless ATM communication network. this paper shows the network model for the mobility support of connectionless data service in ATM network, and proposes the methods to minimize COIP (care of IP address) acquisition processing time for MH(mobile host)migration. Th echaracteristics of proposed methods, COIP acquisition probability and IP data communication sequence of proposed model, are discussed in this paper.

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A New Local Information Distribution System on Multi-Hop Wireless Networks

  • Koide, Toshio;Watanabe, Hitoshi
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1363-1366
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    • 2002
  • The studies of multi-hop wireless networks are active as the new communication media, which does not require any fixed communication infrastructure. One of application of the networks is local information distribution service, which is useful far daily activities in certain geographically restricted region or community within a radius of several kilometers. In this paper, MID-Net, which is the network enabling such distribution service, and effective information distribution algorithm MCMS are proposed. The behavior of the MID-Net is characterized by the waiting time function, three types of the functions are proposed in this paper.

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