• Journal of Communications and Networks
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• v.10 no.3
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• pp.301-307
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• 2008

In this paper, the impact of channel sensing methods to IEEE 802.15.4 under the interference of IEEE 802.11b are analyzed. Two different channel sensing methods, energy detection and carrier sense, are considered. An average transmission delay, a throughput, and a power drain rate are used as performance measures. Those performance measures of IEEE 802.15.4 under the interference of IEEE 802.11b are analyzed mathematically. The simulation results are shown to validate the analytic results.

• Journal of Korea Society of Industrial Information Systems
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• v.22 no.3
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• pp.13-18
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• 2017

In this paper, We Numerically Analyze the Performance of the 802.11 Power Save Multi-Poll (PSMP) Operation. From the Analysis, we have Power Saving Efficiency Indicating how much time is Used for Power Consumption Over the Entire Operation Time. Consequently, we can Estimate the Operational Efficiency of the PSMP Operation.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.3
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• pp.80-90
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• 2004

국내 2.3 GHz 휴대인터넷의 본격화에 즈음하여 이동통신에서의 초고속 무선인터넷에 대한 관심이 높아지고 있다. 본 기고에서는 IEEE LAN/MAN Standard Committee내에서 현재 진행중인 무선 표준 화 동향에 대해서 살펴본다. 이미 Wi-Fi라는 이름으로 상용화되어 로컬 환경에서 벗어나 고속의 서비스 및 로밍 서비스를 지원하기 위해서 진행 중인 IEEE 802.11과 각종 가전 제품들의 근거리 통신을 위한 IEEE 802.15, 그리고 차세대 무선 인터넷의 접속 기술로 각광 받고 있는 IEEE 802.16과 단말의 고속 이동을 지원하기 위한 IEEE 802,20, 그리고 마지막으로 이종 망간의 유연한 핸드오버를 지원하기 위한 IEEE 802.21의 표준 진행 결과 및 향후 전망에 대해서 주로 다룬다. (중략)

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.3
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• pp.293-299
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• 2016

Recently, as IoT (Internet of Things) becomes more important, low cost implementation of sensor nodes also becomes critical issues for two well-known standards, IEEE 802.15.4 and IEEE 802.15.6 which stands for WPAN (Wireless Personal Area Network) and WBAN (Wireless Body Area Network), respectively. This paper presents the area-optimized AES-CCM (Advanced Encryption Standard - Counter with CBC-MAC) hardware security engine which can support both IEEE 802.15.4 and IEEE 802.15.6 standards. First, for the low cost design, we propose the 8-bit AES encryption core with the S-box that consists of fully combinational logic based on composite field arithmetic. We also exploit the toggle method to reduce the complexity of design further by reusing the AES core for performing two operation mode of AES-CCM. The implementation results show that the total gate count of proposed AES-CCM security engine can be reduced by up to 42.5% compared to the conventional design.

• The KIPS Transactions:PartC
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• v.13C no.5 s.108
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• pp.567-574
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• 2006

VG-AnyLAN is a local area network standard developed by the IEEE 802.12 project. While preserving the frame format of IEEE 802.3, VG-AnyLAN adopts a new medium access control called Demand Priority where transmission requests of stations are arbitrated by a control hub in a round-robin manner. Unlike CSMA/CD which is the medium access control of IEEE 802.3, the Demand Priority, while providing the maximum bound on the packet delay, does not put the limit on the network segment size. In this paper, we analyze the delay and the channel utilization performances of the medium access control of IEEE 802.12 VG-AnyLAN. We develope an analytic model of the system under assumptions that each station generates traffic of the equal priority and that the packets are of fixed length. Using the analytic model, we obtain the recursive expression of the average channel utilization and the average access delay The numerical results obtained via analysis are compared to the simulation results of the system for a partial validation of our analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6A
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• pp.640-647
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• 2006

This paper describes a design of AES-based CCMP(Counter mode with CBC-MAC Protocol) core for IEEE 802.11i wireless LAN security. To maximize the performance of CCMP core, two AES cores are used, one is the counter mode for data confidentiality and the other is the CBC node for authentication and data integrity. The S-box that requires the largest hardware in ARS core is implemented using composite field arithmetic, and the gate count is reduced by about 27% compared with conventional LUT(Lookup Table)-based design. The CCMP core was verified using Excalibur SoC kit, and a MPW chip is fabricated using a 0.35-um CMOS standard cell technology. The test results show that all the function of the fabricated chip works correctly. The CCMP processor has 17,000 gates, and the estimated throughput is about 353-Mbps at 116-MHz@3.3V, satisfying 54-Mbps data rate of the IEEE 802.11a and 802.11g specifications.

• Information and Communications Magazine
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• v.33 no.3
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• pp.74-79
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• 2016

IT기술의 발전으로 인하여 스마트 폰, 테블릿 PC, 노트북 등의 고사양을 가진 모바일 단말의 보급률이 증가하고 있으며, 모바일 단말이 사용하는 IEEE 802.11 표준 기술 또한 지속적인 보완작업과 개정작업을 통해 지원하는 주파수 대역 확장 되었으며, 데이터 전송속도도 빨라지고 있다. 하지만 기술이 발전하고 있음에도 불구하고, Management Frame의 무결성 확인 과정의 부재로 인한 보안 취약성이 아직 남아 있으며, 이를 악용하는 악성행위자의 ARP Spoofing 공격, AP DoS(Denial of Service) 공격, Mac Spoofing 을 기반한 Rouge AP 공격 등에 취약하다. 공공기관, 회사에서는 위 같은 취약점으로부터 무선네트워크를 보호하기 위해 WIPS 시스템을 도입하였지만, 이 또한 Management Frame의 취약성을 근본적으로 해결 할 수 없었다. 때문에 IEEE 802.11 워킹그룹은 Management Frame 보안성을 향상시킨 IEEE 802.11w-2009 표준 기술이 제안 하였으며, 이로 인해 Management Frame의 무결성을 확인하지 않아 발생하는 취약성으로 인한 보안 위협을 근본적으로 방지 할 수 있게 되었다. 하지만 IEEE 802.11w 표준 환경을 적용함으로써 새로운 유형의 보안 위협이 발생되었다. 따라서 본고에서는 IEEE 802.11w 표준에 대하여 살펴보며, IEEE 802.11w 표준 환경에서의 보안 기술에 대한 동향 알아본다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.438-440
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• 2010

As market expansion and demand for smart phone have increased, the wireless data trafic is rapidly growing now. To solve this problem, common carriers in Korea distribute the trafic over Wi-Fi. Smart phones have multi interfaces such as 3G radio, Wi-Fi, Bluetooth, and etc and can utilize them. However these interfaces support seamless handover between not different interfaces but same interfaces, so that users couldn't be supported continuity for handover. In this paper, we describe the Media Independent Handover(MIH) services that is proposed by IEEE 802.21. The standard enhance the handovers across heterogeneous access networks and to optimize the service continuity during handovers.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.233-236
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• 2000

본 논문에서는 다중 경로 페이딩에 의한 성능의 손실을 보상하기 위하여 간단한 equal gain combining diversity를 갖는 802.11a 무선 LAN용 OFDM 시스템의 HER 성능을 다중경로 환경 하에서 분석하였다. 모의 실험 결과에 따르면, 다중경로채널에서 전송 파워를 살펴보면, 2branch equal gain combining diversity를 사용한 무선 LAN용 OFDM시스템이 diversity를 사용하지 않는 OFDM 시스템보다 BER 10/sup -3/에서 3㏈ 정도의 이득을 줄 수 있었다. Branch 수를 3개를 사용한 경우에는 BER 10/sup -3/에서 branch 2개를 사용한 경우보다 약 2㏈정도 이득을 줄 수 있었다.

• Journal of the Korea Society of Computer and Information
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• v.25 no.11
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• pp.89-95
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• 2020

In this paper, we present Beamforming (BF) Training (BFT) for asymmetric links in IEEE 802.11ay. IEEE 802.11ay introduced BFT for asymmetric links that aims to increase the BFT success probability for Station (STA) with insufficient link budget to communicate with an Access Point (AP). BFT for asymmetric links utilizes directional BFT allocation to avoid the usage of quasi-omni pattern at the AP side, and thus to increase STA's BFT success rate. However, there are no publicly available simulation tools supporting IEEE 802.11ay. For these reasons, we present in this paper an implementation of BFT for asymmetric links in ns-3 with its novel techniques such as Training RX (TRN-R) subfield and BFT allocation. We then evaluate by simulation the performance of BFT for asymmetric links.