• Title, Summary, Keyword: wireless local area network(WLAN)

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A Design of Security Mechanism to control LR-WPAN in WLAN (LR-WPAN을 제어하기 위한 WLAN에서의 보안 매커니즘 설계)

  • Lee, Jae-Won;Hong, Choong-Seon
    • Proceedings of the Korean Information Science Society Conference
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    • pp.178-180
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    • 2005
  • 저렴한 비용, 매우 작은 파워 소비라 낮은 데이터 전송속도를 지원 하는 IEEE 802.15.4 LR-WPAN(Wireless Personal Area Network) 기술은 앞으로 다가올 유비쿼터스 시대의 핵심이라고 할 수 있다. 도래할 유비쿼터스 시대에는 댁내에 LR-WPAN 기술을 적용한 다양한 상품이 보급될 것이다. 그러나 LR-WPAN은 매우 낮은 전력 소비를 위해 네트워크 기능을 최소화 하였기 때문에 응용에 있어 LAN 또는 WLAN(Wireless Local Area Network)등 기존 네트워크와의 통신 및 보안이 아직 고려되지 않아 보완이 필요하다. 본 논문에서는 WLAN의 Station이 LR-WPAN을 보안적으로 안전하게 제어할 수 있도록 AP(Acess Point)와 WLAN의 Station 그리고 LR-WPAN의 PAN Coodinator 간의 새로운 Message와 Function를 정의하고, 다른 두 네트워크간의 효율적이고 보안이 유지되는 프레임 프로세싱 매커니즘을 제안한다.

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AAA System for PLMN-WLAN Internetworking

  • Janevski Toni
    • Journal of Communications and Networks
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    • v.7 no.2
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    • pp.192-206
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    • 2005
  • Integration of mobile networks and Internet has started with 2.5 generation of mobile cellular networks. Internet traffic is today dominant traffic type worldwide. The hanger for higher data rates needed for data traffic and new IP based services is essential in the development of future wireless networks. In such situation, even 3G with up to 2 Mbit/s has not provided data rates that are used by Internet users with fixed broadband dial-up or through wired local area networks. The solution to provide higher bit rates in wireless access network has been found in wireless LAN although initially it has been developed to extend wired LAN into wireless domain. In this paper, we propose and describe a solution created for interoperability between mobile cellular network and WLAN. The integration between two networks, cellular and WLAN, is performed on the authentication, authorization, and accounting, i.e., AAA side. For that purpose we developed WLAN access controller and WLAN AAA gateway, which provide gateway-type access control as well as charging and billing functionalities for the WLAN service. In the development process of these elements, we have considered current development stadium of all needed network entities and protocols. The provided solution provides cost-effective and easy-to-deploy PLMN-WLAN Internetworking scenario.

A WLAN/GPS Hybrid Localization Algorithm for Indoor/Outdoor Transit Area (실내외 천이영역 적용을 위한 WLAN/GPS 복합 측위 알고리즘)

  • Lee, Young-Jun;Kim, Hee-Sung;Lee, Hyung-Keun
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.6
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    • pp.610-618
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    • 2011
  • For improved localization around the indoor/outdoor transit area of buildings, this paper proposes an efficient algorithm combining the measurements from the WLAN (Wireless Local Area Network) and the GPS (Global Positioning System) for. The proposed hybrid localization algorithm considers both multipath errors and NLOS (Non-Line-of-Sight) errors, which occur in most wireless localization systems. To detect and isolate multipath errors occurring in GPS measurements, the propose algorithm utilizes conventional multipath test statistics. To convert WLAN signal strength measurements to range estimates in the presence of NLOS errors, a simple and effective calibration algorithm is designed to compute conversion parameters. By selecting and combining the reliable GPS and WLAN measurements, the proposed hybrid localization algorithm provides more accurate location estimates. An experiment result demonstrates the performance of the proposed algorithm.

Circular Ring Open-Ended Monopole Antenna with Strip for WLAN Dual-Band Operations

  • Yoon, Joong-Han
    • Journal of information and communication convergence engineering
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    • v.12 no.1
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    • pp.1-7
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    • 2014
  • A novel design of a simple circular ring with open-ended monopole antenna for wireless local area network (WLAN) applications is proposed in this article. The proposed antenna consists of an open-ended circular ring and $50-{\Omega}$ microstrip feed-line. The proposed antenna is capable of generating two separate resonant modes with good impedance-matching conditions. A prototype of the proposed antenna is designed, fabricated, and measured. Acceptable agreement between the measurement and simulation results is achieved. Experimental results show that the proposed antenna has operating bandwidths of 1.99-3.04 GHz and 5.08-6.1 GHz with a return loss of less than -10 dB, covering the required bandwidths of the 2.4/5.2/5.8-GHz WLAN standards. This is a microstrip antenna for IEEE 802.11a/b wireless local area networks applications. Meanwhile, the two-dimensional (2D) radiation patterns and three-dimensional (3D) gain performance of the antenna are also observed and discussed.

Packet Discrimination Method Using Artificial Frequency Offsets for Low Decoding Power Consumption in Heterogeneous Cooperative Communication Systems (이기종 협력 통신시스템에서 디코딩 전력소모 감소를 위한 인위적인 주파수 오프셋을 이용한 패킷 구별 기법)

  • Chae, Seungyeob;Yeo, Gyuhak;Rim, Minjoong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39A no.7
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    • pp.372-379
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    • 2014
  • When a hand-held device with limited battery transmits and receives data using short-range wireless communication systems, such as WLAN(Wireless Local Area Network) or high speed WPAN(Wireless Personal Area Network), instead of mobile communication systems, the device is able to reduce the power consumption due to the reduced transmission distance. However, if there are many WLAN or high speed WPAN systems around the device, non-negligible power may be consumed by receiving and decoding the packets which have nothing to do with the device. In this paper, we propose a scheme reducing the power consumption by including physical-layer ID in WLAN or WPAN packets and avoiding unnecessary packet receptions. Also, we describe a method to determine the optimum number of physical-layer IDs.

MAC Throughput Analysis of MAC Aggregation and Block ACK in IEEE 802.11n (MAC 프레임 집합 전송과 블록 ACK 사용에 따른 IEEE 802.11n 수율 분석)

  • Moon, Kuk-Hyun;Chung, Min-Young;Cho, Kang-Yun
    • Proceedings of the KIEE Conference
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    • pp.467-469
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    • 2006
  • In wireless network environments, as users' demands on high-speed data communications due to increase of multi-media services, the necessity of new high-speed WLAN technologies has appeared. Nowaday, IEEE is standardizing a new WLAN protocol caned as IEEE 802.11n. To effectively use wireless resources, IEEE 802.11n introduces MAC aggregation function which is similar to that in IEEE 802.11e. In case of transmitting several frames without MAC aggregation, the frames include individual frame header and trailer, and their corresponding acknowledgement frames can appear on wireless link. However, if they are aggregated into single MAC frame, we can reduce the number of used bits due to frame headers/trailers and also remove redundant acknowledgement frames. In this paper, we explain two different MAC frame aggregation methods for IEEE 802.11e and IEEE 802.11n and evaluate their throughput by simulations.

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The Development of a Network based Visual Agent Platform for Tangible Space (실감 만남을 위한 네트워크 기반 Visual Agent Platform 개발)

  • Kim, Hyun-Ki;Choy, Ick;You, Bum-Jae
    • Proceedings of the KIEE Conference
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    • pp.172-174
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    • 2007
  • In this paper, we designed a embedded system that will perform a primary role of Tangible Space implementation. This hardware includes function of image capture through camera interface, image process and sending off image information by LAN(local area network) or WLAN(wireless local area network). We define this hardware as a network based Visual Agent Platform for Tangible Space, This Visual Agent Platform includes the software that is RTLinux and CORBA

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Implementation of Mini Chip Antenna suitable for Ubiquitous Environment (유비쿼터스 환경에 적합한 소형 칩 안테나 구현)

  • Kang, Jeong-Jin;Choi, Jong-In;Lee, Young-Dae;Hong, You-Sik
    • The Journal of The Institute of Internet, Broadcasting and Communication
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    • v.8 no.3
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    • pp.81-86
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    • 2008
  • The paradigm of information & communication is rapidly changed into ubiquitous environment based electromagnetic wave, and antenna technology in the wireless ubiquitous communication is remarkably developed. Mini chip antenna has its within small card compared to the external AP antenna. Designed and Fabricated WLAN antenna has a broadband characteristics of 2.4~2.5GHz and 4.9~5.85GHz, and can be used triple mode of IEEE 802.11.a,g.b, and it has comparatively a constant performance in the dual frequency band.

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2.4 GHz WLAN InGaP/GaAs Power Amplifier with Temperature Compensation Technique

  • Yoon, Sang-Woong;Kim, Chang-Woo
    • ETRI Journal
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    • v.31 no.5
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    • pp.601-603
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    • 2009
  • This letter presents a high performance 2.4 GHz two-stage power amplifier (PA) operating in the temperature range from $-30^{\circ}C$ to $+85^{\circ}C$ for IEEE 802.11g, wireless local area network application. It is implemented in InGaP/GaAs hetero-junction bipolar transistor technology and has a bias circuit employing a temperature compensation technique for error vector magnitude (EVM) performance. The technique uses a resistor made with a base layer of HBT. The design improves EVM performance in cold temperatures by increasing current. The implemented PA has a dynamic EVM of less than 4%, a gain of over 26 dB, and a current less than 130 mA below the output power of 19 dBm across the temperature range from $-30^{\circ}C$ to $+85^{\circ}C$.

Wideband Bandstop Filter Based on Capacitively Coupled λ/4 Short-Circuited Lines

  • Duong, Thai Hoa;Kim, Ihn-Seok
    • Journal of electromagnetic engineering and science
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    • v.10 no.3
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    • pp.92-98
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    • 2010
  • A new wideband bandstop filter(BSF) with a sharp roll-off characteristic is introduced in a stripline structure in this paper. The BSF consists of two sections: the first is two capacitively coupled $\lambda/4$ short-circuited lines with opposite ground positions, while the second is a capacitively coupled $\lambda/4$ short-circuited line. The BSF provides three transmission zeros within the stopband and better than 22 dB rejection over the whole wireless local area network (WLAN) band from 5.15 to 5.825 GHz. The BSF, cascaded to an U.S. ultra-wideband(UWB: 3.1~10.6 GHz) band-pass filter(BPF), is simulated with HFSS and realized with low-temperature co-fired ceramic(LTCC) green tape with a dielectric constant of 7.8. The measurement results agree well with the HFSS simulation results. The size of the UWB BPF including the BSF is $3{\times}6.3\times0.45\;mm^3$.