• Title, Summary, Keyword: WLAN Network

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The Power Saving Strategy of Dual Mode Access Terminal in WiBro and WLAN Hierarchical Network (WiBro/WLAN Hierarchical 네트워크에서 듀얼모드 단말기의 Power Saving 전략)

  • Moon, Tae-Wook;Ko, Bong-Jin;Cho, Sung-Joon
    • The Journal of Advanced Navigation Technology
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    • v.10 no.4
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    • pp.306-311
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    • 2006
  • When the WiBro/WLAN hierarchical network is structured, a dual mode access terminal should keep WLAN module with power on state for operating in WiBro network outside of WLAN hotspot zone. Power consumption of user's access terminal can be increased to maintain WLAN module power on state of dual mode access terminal in WiBro network outside of the hotspot zone. This paper focuses on power saving strategy for a dual mode access terminal in WiBro/WLAN Hierarchical network to overcome problems regarding power. We will apply information about hotspot in WiBro network to establish the efficient power saving strategy for dual mode access terminal.

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Smart WLAN Discovery for Power Saving of Dual-Mode Terminals

  • Park, Hyunho;Lee, Hyeong Ho
    • ETRI Journal
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    • v.35 no.6
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    • pp.1144-1147
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    • 2013
  • Dual-mode terminals (DMTs) equipped with cellular and WLAN interfaces have become popular in recent years. Users of DMTs can enjoy high-speed WLAN Internet access and wide area Internet access to cellular networks. However, a DMT may consume power inefficiently when discovering a WLAN with inherently limited service coverage. In this letter, we propose to use smart WLAN discovery (SWD) to minimize the power consumption required for WLAN discovery. To minimize the power consumption of a DMT, an SWD DMT activates its WLAN interface only when the DMT transfers data within the WLAN coverage area. The simulation results of SWD show an improved power-saving performance compared to previous WLAN discovery schemes.

Mobile Communication Network to Access Technologies Utilizing Unlicensed Spectrum Interworking (이동 통신 망과 Unlicensed Spectrum 을 사 용하는 Access 기술과의 연동 방법)

  • Shim, Dong-Hee;Son, Sung-Mu;Kim, Ki-Yeol
    • 한국정보통신설비학회:학술대회논문집
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    • pp.354-358
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    • 2007
  • This article presents several methods of mobile communication network to access technologies utilizing unlicensed spectrum interworking. Generic Access Network (GAN) technology was already specified in GERAN (GSM EDGE Radio Access Network) and Interworking WLAN (I-WLAN) was standardized for WCDMA system for WLAN user to access WCDMA packet based services through WLAN access point. Voice Call Continuity is not access network dependent technology but is a kind of domain change scheme for voice call from Circuit Switching (CS) network to IP Multimedia Subsystem (IMS) and vice versa.

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WLAN CR Coexistence Beacon Protocol for Cognitive Radio-Based WLAN Network (무선인지 기술을 이용한 차세대 WLAN 네트워크에서의 WLAN CR 공존 비콘 프로토콜)

  • Kim, Hyun-Ju;Yoo, Sang-Jo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.12B
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    • pp.790-799
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    • 2007
  • In this paper, we propose WLAN CR coexistence beacon protocol for thenext WLAN network. This method can provide WLAN with high-speed data rate in new WLAN architecture and network platform based on cognitive radio technology. WLAN CR devices that enter the CR network can know UHF channels by listening CR beacon including the coexistence parameter set and start using CR channel fast. During handover of WLAN device in UHF spectrums, WLAN device that lost their channel can change available channel by obtaining the current CR channel information from the CR beacon. In advance relaying coexistence parameter set to entire CR system, WLAN CR system can prepare own candidate channel set that is different with other CR system. In CR beacon and relay delay, we show the results that WLAN CR coexistence beacon protocol supports spectrum handover efficiently and decreases the probability of collision in candidate channel set.

WLAN Security Access Protocol for Rapid Initial Link Setup Process (신속한 초기 링크 셋업 과정을 위한 WLAN 보안 접속 프로토콜)

  • Kim, Min-Hee;Park, Chang-Seop
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.25 no.6
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    • pp.1515-1523
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    • 2015
  • It has been prevalent to be serviced through WLAN(Wireless Local Area Network) as a variety of mobile devices have been introduced. If the number of mobile devices increases rapidly for the network access in a limited range of ESS(Extended Service Set), a lengthy connection delays are induced due to the initial link setup process of the IEEE 802.11i which is WLAN security standard. In this paper, we propose a new initial link setup protocol which can be executed in the ESS area of WLAN.

Performance Analysis of Joint Call Admission Control(JCAC) According to Resource Reservation Rate Changes in LTE-WLAN Heterogeneous Network Environment (LTE-WLAN 이종 네트워크 환경에서 자원예약률 변화에 따른 통합 호 수락 제어의 성능분석)

  • Kim, Yi-Kang;Kim, Seung-Yeon;Ryu, Seung-Wan;Cho, Choong-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.5A
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    • pp.473-484
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    • 2011
  • In this paper, we analyze and propose the Joint Call Admission Control(JCAC) scheme to combine network selection scheme and radio resource reservation based Call Admission Control(CAC) in LTE-WLAN heterogeneous networks. First, We propose the JCAC system that uses network decision rate to select a network for terminal and radio resource reservation scheme in overlaying LTE-WLAN network environment. And we analyze the performance of a proposed system using markov chain model. The performance is presented in terms of the new call blocking probability, handoff call dropping probability, and channel utilization of each network. As a performance result of the our research, the system using JCAC is better than the system using non-JCAC. We found a suitable resource reservation rate that is 10% in the system using JCAC. Our work may be useful as a guideline of resource reservation rate to introduce JCAC system using resource reservation scheme in overlaying LTE-WLAN network environment.

Cognitive Beamforming Based Smart Metering for Coexistence with Wireless Local Area Networks

  • Lee, Keonkook;Chae, Chan-Byoung;Sung, Tae-Kyung;Kang, Joonhyuk
    • Journal of Communications and Networks
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    • v.14 no.6
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    • pp.619-628
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    • 2012
  • The ZigBee network has been considered to monitor electricity usage of home appliances in the smart grid network. ZigBee, however, may suffer from a coexistence problem with wireless local area network (WLAN). In this paper, to resolve the coexistence problem between ZigBee network and WLAN, we propose a new protocol constructing a cognitive smart grid network for supporting monitoring of home appliances. In the proposed protocol, home appliances first estimates the transmission timing and channel information of WLAN by reading request to send/clear to send (RTS/CTS) frames of WLAN. Next, based on the estimated information, home appliances transmit a data at the same time as WLAN transmission. To manage the interference between WLAN and smart grid network, we propose a cognitive beamforming algorithm. The beamforming algorithm is designed to guaranteeing zero interference to WLAN while satisfying a required rate for smart metering. We also propose an energy efficient rate adaptation algorithm. By slowing down the transmission rate while satisfying an imperceptible impact of quality of service (QoS) of the receiver, the home appliance can significantly save transmit power. Numerical results show that the proposed multiple antenna technique provides reliable communications for smart metering with reduced power comparing to the simple transmission technique.

DIAMETER Strong Security Extension using Kerberos v5 in WLAN (WLAN에서 Kerberos v5를 이용하여 안전성을 강화한 DIAMETER의 확장)

  • Wiroon, Sriborrirux;Kim, Tai-Yun
    • Proceedings of the Korea Information Processing Society Conference
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    • pp.1023-1026
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    • 2002
  • The demand for Wireless LAN (WLAN) access to use their network and the Internet is surged dramatically over the past year. Since WLAN provides users' access from anywhere in the workplace without having to plug in, it therefore leads the WLAN market to grow steadily. Unfortunately, the first WLAN implementation designed primarily for home networking did little to address these security issues. Moreover, although the 802.11b standard published by IEEE in 1999 improved WLAN connections LAN-equivalent speed and security from the 802.11 standard. However, there still are several flaws such as the weaknesses in the Authentication and WEP encryption schemes in the IEEE 802.11 WLAN standard. In this paper, we propose WLAN architecture for providing the strong centralized authentication, encryption, and dynamic key distribution on a WLAN. Additionally, this proposed architecture is able to support roaming users and is flexible and extensible to future developments in the network security.

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Performance Analysis of Routing Protocols for WLAN Mesh Networks (WLAN Mesh 망을 위한 라우팅 기법의 성능 분석)

  • Park, Jae-Sung;Lim, Yu-Jin;Ahn, Sang-Hyun
    • The KIPS Transactions:PartC
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    • v.14C no.5
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    • pp.417-424
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    • 2007
  • Mesh networks using WLAN technology have been paid attention as a key wireless access technology. However, many technical issues still exist for its successful deployment. One of those issues is the routing problem that addresses the path setup through a WLAN mesh network for the data exchanges between a station and a wired network. Since the characteristics of a WLAN mesh network can be very dynamic, the use of single routing protocol would not fit for all environments whether it is reactive or proactive. Therefore, it is required to develop an adaptive routing protocol that modifies itself according to the changes in the network parameters. As a logical first step for the development, an analytical model considering all the dynamic features of a WLAN mesh network is required to evaluate the performance of a reactive and a proactive routing scheme. In this paper, we propose an analytical model that makes us scrutinize the impact of the network and station parameters on the performance of each routing protocol. Our model includes the size of a mesh network, the density of stations, mobility of stations. and the duration of network topology change. We applied our model to the AODV that is a representative reactive routing protocol and DSDV that is a representative proactive routing protocol to analyze the tradeoff between AODV and DSDV in dynamic network environments. Our model is expected to help developing an adaptive routing protocol for a WLAN mesh network.

Implementation of Fiber Optic and Wireless Complex Communication Network for Distribution Automation using IEEE 802.11a WLAN technology (IEEE 802.11a WLAN 기술의 사용에 의한 배전자동화용 광무선 복합통신망의 구현)

  • Hwang, Jin-Kwon;Choi, Tae-Il
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.10
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    • pp.49-57
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    • 2010
  • In order to provide electricity to users economically and safely, distribution automation systems (DASs) monitor and operate components of distribution systems remotely through communication networks. The fiber optic communication network has been mainly installed for the DAS of Korea Electric Power Corporation (KEPCO) because of its huge bandwidth and dielectric noise immunity. However, the fiber optic communication network has some shortcomings that its installation cost and communication fee are expensive. This paper proposes a complex network where WLANs are combined with conventional fiber optic communication networks in order to expand DAS easily and inexpensively. A fixed wireless bridge communication unit (FWB-CU) for the proposed complex network is implemented using IEEE 802.11a WLAN technology. The proposed complex network is built actually to verify its feasibility experimentally as a DAS communication network.