• Journal of Internet Computing and Services
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• v.15 no.3
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• pp.63-69
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• 2014

For the safety messages in IEEE 802.11p vehicles network environment(WAVE), strict periodic beacon broadcasting requires status advertisement to assist the driver for safety. WAVE standards apply multiple radios and multiple channels to provide open public road safety services and improve the comfort and efficiency of driving. Although WAVE standards have been proposed multi-channel multi-radio, the standards neither consider the WAVE multi-radio environment nor its effect on the beacon broadcasting. Most of beacon broadcasting is designed to be delivered on only one physical device and one control channel by the WAVE standard. also conflict-free channel assignment of the fewest channels to a given set of radio nodes without causing collision is NP-hard, even with the knowledge of the network topology and all nodes have the same transmission radio. Based on the latest standard IEEE 802.11p and IEEE 1609.4, this paper proposes an interference aware-based channel assignment algorithm with Nash bargaining solution that minimizes interference and increases throughput with wireless mesh network, which is deigned for multi-radio multi-cahnnel structure of WAVE. The proposed algorithm is validated against numerical simulation results and results show that our proposed algorithm is improvements on 8 channels with 3 radios compared to Tabu and random channel allocation algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.3A
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• pp.221-229
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• 2007

In this paper, we propose and analyze the optimized sleep mode for a mobile node (MN) in IEEE 802.16e wireless metropolitan area networks. Because a MN in a sleep mode specified in 802.16e specification should maintain state information with the base station currently attached, it must renew sleep state with a new base station after handover which leads to unnecessary waste of battery power. Noting that the mobility pattern of a MN is independent of call arrival patterns, we propose an optimized sleep mode to eliminate unnecessary standby period of a MN in sleep state after handover. We also propose an analytical model for the proposed scheme in terms of power consumption and the initial call response time. Simulation studies that compare the performance between the sleep mode and the optimized sleep mode show that our scheme marginally increases initial call response delay with the huge reduction in power consumption.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.2
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• pp.363-371
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• 2013

This paper describes a multi-standard LDPC decoder which supports 19 block lengths(576~2304) and 6 code rates(1/2, 2/3A, 2/3B, 3/4A, 3/4B, 5/6) of IEEE 802.16e mobile WiMAX standard and 3 block lengths(648, 1296, 1944) and 4 code rates(1/2, 2/3, 3/4, 5/6) of IEEE 802.11n WLAN standard. To minimize hardware complexity, it adopts a block-serial (partially parallel) architecture based on the layered decoding scheme. A DFU(decoding function unit) based on sign-magnitude arithmetic is used for hardware reduction. The designed LDPC decoder is verified by FPGA implementation, and synthesized with a 0.13-${\mu}m$ CMOS cell library. It has 312,000 gates and 70,000 bits RAM. The estimated throughput is about 79~210 Mbps at 100 MHz@1.8v.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.93-93
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• 2004

• Information and Communications Magazine
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• v.26 no.12
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• pp.41-49
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• 2009

3GPP LTE/LTE-A and IEEE 802.16m have recently been submitted to ITU as IMT-Advanced candidates. MIMO is one of the core technologies that enable both standards to achieve the tough requirements specified by ITU. This paper provides an introduction to the core downlink MIMO features of both standards.

• The Magazine of the IEIE
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• v.29 no.10
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• pp.1175-1175
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• 2002

2002년 6월, IEEE 802.3ae 10Gb/s 이더넷이 표준으로 승인되었다. 10 Gb/s 이더넷은 MAC 부계층과 물리계층을 통합한 규격으로 전이중 방식 및 광섬유 매체만을 제공한다. 기존 이더넷과 동일한 프레임 형식을 사용하고, LAN 물리계층과 WAN 물리계층까지 지원하고 있다. 따라서 LAN, MAN, WAN 영역에서 10Gb/s의 높은 속도를 제공할 수 있으며, 기존의 이더넷과 투명하게 통합할 수 있다. 본 논문에서는 10 기가비트 이더넷의 MAC 부계층과 물리계층 및 최근 기술 동향을 살펴본다.

• The Magazine of the IEIE
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• v.29 no.10
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• pp.29-38
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• 2002

2002년 6월, IEEE 802.3ae 10Gb/s 이더넷이 표준으로 승인되었다. 10 Gb/s 이더넷은 MAC 부계층과 물리계층을 통합한 규격으로 전이중 방식 및 광섬유 매체만을 제공한다.기존 이더넷과 동일한 프레임 형식을 사용하고, LAN 물리계층과 WAN 물리계층까지 지원하고 있다. 따라서 LAN, MAN, WAN 영역에서 10Gb/s의 높은 속도를 제공할 수 있으며, 기존의 이더넷과 투명하게 통합할 수 있다. 본 논문에서는 10 기가비트 이더넷의 MAC 부계층과 물리계층 및 최근 기술 동향을 살펴본다.

• Honam Mathematical Journal
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• v.33 no.2
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• pp.153-161
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• 2011

Greg([Greg]) considered that $$N_k= \sum\limits_{i=1}^k(-1)^{i+1}P_{i,k}(p)N_1^i$$ where the $P_{i,k}$'s were polynomials with positive integer coefficients. In this paper, we will give the equations for $\sum\limits{P_{i,k}$ modulo 3. Using this, if we send a information for elliptic curve to sender, we can make a new checksum method for Manchester coding in IEEE 802.3 or IEEE 802.4.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.30-30
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• 2004

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.29-29
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• 2004