THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. 2014 May; 25(5), 526 531. http://dx.doi.org/10.5515/kjkiees.2014.25.5.526 ISSN 1226-3133 (Print) ISSN 2288-226X (Online) MAC IEEE 802.11p WAVE Performance Evaluation of IEEE 802.11p Based WAVE Communication Systems at MAC Layer 최광주 김진관 박상규 Kwang Joo Choi Jin Kwan Kim Sang Kyu Park 요약 ITS(Intelligent Transport Systems). WAVE(Wireless Access in Vehicular Environments) IEEE 802.11p/ 1609 vehicle-to-vehicle(v2v) vehicle-to-infra(v2i). WAVE OFDM(Orthogonal Frequency Division Multiplexing) 5.835 5.925 GHz. IEEE 802.11p WAVE MAC(Media Access Control) 32. OBU(On Board Unit), OBU WSM(WAVE Short Message),. Abstract Vehicular communications have been receiving much attention in intelligent transport systems(its) by combining communication technology with automobile industries. In general, vehicular communication can be used for vehicle-to-vehicle(v2v) and vehicle-to- infrastructure(v2i) communication by adopting IEEE802.11p/1609 standard which is commonly known as wireless access in vehicular environment(wave). WAVE system transmits signal in 5.835 5.925 GHz frequency band with orthogonal frequency division multiplexing(ofdm) signaling. In this paper, after 32 bit processed the channel monitoring in MAC(Media Access Control) layer of WAVE system implemented according to IEEE 802.11p standard, data were received and we evaluated the performance, we built the test bed consisting of OBU(On Board Unit) in the real expressway. We transmitted WSM(WAVE Short Message) and received WSM between OBU wirelessly. And then, we calculated channel occupancy time per one frame and throughput, and evaluated the performance. Key words: WAVE, OFDM, 5.9 GHz. 서론, -, ITS(Intelligent Transport Systems). (Department of Electronics and Computer Engineering, Hanyang University). Manuscript received December 16, 2013 ; Revised March 31, 2014 ; Accepted March 31, 2014. (ID No. 20131216-128) Corresponding Author: Sang Kyu Park (e-mail: skpark@hanyang.ac.kr) 526 c Copyright The Korean Institute of Electromagnetic Engineering and Science. All Rights Reserved.
MAC IEEE 802.11p WAVE. WAVE IEEE 802.11p [1]. IEEE 802.11p IEEE 802.11 a/g. ISM(Industry-Science-Medical) 5.850 5.925 GHz, OFDM 10 MHz 1. (data rate) 10 MHz BPSK, QPSK, 16QAM, 64QAM 3 27 Mbps. OFDM 64, 48, 4, 12. 1 IEEE 802.11p OFDM 표 1. IEEE802.11p OFDM Table 1. Properties of OFDM signal in IEEE 802.11p. 10 MHz FFT 64 IFFT / FFT Guard interval 0.15625 MHz 8.28 MHz 표 2. IEEE 802.11p OFDM Table 2. Transmission mode of OFDM signal according to the data rate in IEEE 802.11p. Data rate (Mbits/s),,,. IEEE 802.11 ASTM(American Society for Testing and Materials) WAVE(Wireless Access In Vehicular Environment), 2004 TGp (Task Group p) [1]. IEEE 802.11p WAVE 200 km/h 27 Mbps WBSS(WAVE Basic Service Set) IEEE 802.11 [2]. IEEE 802.11p WAVE vehicular Ad-Hoc networks(vanets) DSRC. V2V V2I [3].,, infotainment. WAVE,,. 16 32 WAVE IEEE 802.11p. WA- VE OBU, OBU.. WAVE, WAVE.,.. WAVE 물리계층 WAVE Modulation Coding rate Coded bits per subcarrier Coded bits per OFDM symbol Data bits per OFDM symbol 3 BPSK 1/2 1 48 24 4.5 BPSK 3/4 1 48 36 6 QPSK 1/2 2 96 48 9 QPSK 3/4 2 96 72 12 16-QAM 1/2 4 192 96 18 16-QAM 3/4 4 192 144 24 64-QAM 2/3 6 288 192 27 64-QAM 3/4 6 288 216 527
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 25, no. 5, May 2014. [1]. [1]. 2 OFDM IEEE 802.11p, 44.8 dbm [1].. WAVE 매체접근제어프레임구조 1 timing advertisement(ta). TA (frame control), (duration)/id(identification), (destination address), (start address), BBS(basic service set) ID, (sequence control), (frame body), (frame check sequence).,,. /ID.. ACK(acknowledge) /ID (fragment) ACK.. BBS ID,,,,.., (local area network) (broadcast). 그림 1. WAVE MAC Fig. 1. Frame structure of the WAVE MAC. 그림 2. WAVE MAC Fig. 2. Detail structure of WAVE MAC frame. 1. 16 4 MS- DU(MAC Service Data Unit), 12 MSDU.,. 2 1 MAC. MAC - (time-stamp), capability, country, (power constraint), TA, capability(extended capability), (vendor specific).,. MSDU LLC (Logical Link Control). MAC. 0. 1 (1). (1) β,. LPDU(LLC Protocol Data Unit) n β, n β 0.,,, 528
MAC IEEE 802.11p WAVE 16 32 MAC. 16 32.. 4-1 시험방법. 시험및결과 WAVE OBU. 4 km, line of sight(los), 표 3. Table 3. Test equipment parameters. Standard RF MAC LLC PHY Channel bandwidth Frequency Tx power Rx sensitivity Stability IEEE1609.4 IEEE1609.3 IEEE802.11P 10 MHz 5.860 GHz 24 dbm (max 28.8 dbm) 85 dbm ± ppm(max) Antenna Gain 9 dbi Data Time Data rate Modulation Link access Packet latency 9 Mbps QPSK OFDM msec msec Distance Communication area 2.3 km Velocity Vehicle speed 100 kph System Power source GPS V2V Interface DC 12 V Ublox Vehicle to vehicle communication Ethernet, USB, UART. WAVE OBU. WSM(WAVE Short Message). QPSK 3/4, ACK 9 Mbits/s, OBU., 100 km/h. WSM, 2,300 m. 3 test. 4-2 시험결과 6. 32 MAC 60.08 us, 16 MAC 117.66 us. 32 MAC 16 MAC 57.58 us. 7 V2I 9 dbi, 9 Mbps,. 16 2.9841 Mbit/sec, 32 그림 3. QPSK OFDM Fig. 3. The time to send a frame of QPSK OFDM. 529
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 25, no. 5, May 2014.. References 그림 4. V2I Fig. 4. Throughput performance in V2I. 4.2515 Mbit/sec. 32 16 1.2674 Mbit/sec. bathtub, 32 16 bathtub... 결론 16 32 WAVE IEEE 802.11p, WAVE WSM., OBU WSM. V2I., 16 MAC 32 2, 32 16 42.47 % [1] Task Group p, IEEE Std 802.11p, "IEEE standard for information technology-telecommunications and information exchange between systems-local and metropolitan area networks-specific requirements Part 11: Wireless LAN Medium Access Control(MAC) and Physical Layer(PHY) Specifications Am", draft standard ed., IEEE Computer Society, 2010. [2] D. Jiang, L. Delgrossi, "IEEE 802.11p: Towards an international standard for wireless access in vehicular environments", Proc. IEEE VTC-Spring, May 2008. [3] F. Bai, H. Krishnan, "Reliability analysis of DSRC wireless communication for vehicle safety applications", Proc. of Intelligent Transportation Systems Conference, pp. 355-362, 2006. [4] G. Acosta-Marum, M. A. Ingram, "Six time-and frequency-selective empirical channel models for vehicular wireless LANs", IEEE Vehicular Technology Magazine, vol. 2, no. 4, pp. 4-11, Dec. 2007. [5] S. Biswar, R. Tatchikou, and F. Dion, "Vehicle-to-vehicle wireless communication protocols for enhancing highway traffic safety", IEEE Commun. Mag., vol. 44, no. 1, pp. 74-82, Jan. 2006. [6] P. Alexander, D. Haley, and A. Grant, "Cooperative intelligent transport systems: 5.9-GHz field trials", Proc. IEEE, vol. 99, no. 7, pp. 1213-1235, Jul. 2011. 530
MAC 최광 주 년 8월: 한양대학교 전자통신공학과 공학사) 년 8월: 한양대학교 전자통신공학과 공학석사) 년 11월 2008년 5월: LG전자연구소 책임연구원 2008년 5월 현재: 아이티텔레콤 대표이 사 2002년 9월 현재: 한양대학교 전자컴퓨터통신공학과 박사과 정 [주 관심분야] C-ITS시스템, DSRC 기술, WAVE 통신시스템 및 응용서비스 등 계층에서의 IEEE 802.11p 기반 WAVE 통신 시스템의 성능 평가 박상 규 1981 ( 1990 ( 1990 년 서울대학교 전기공학과 공학사) 년 공학석사 년 공학박사) 년 현재 한양대학교 융합전자공학 부 교수 [주 관심분야] 차세대 이동통신 시스템, 확 산대역통신, MIMO-OFDM, Relay Commu1974 : ( 1980 : Duke University ( ) 1987 : University of Michigan ( 1987 : nications 김진 관 년 2월: 충북대학교 전기전자컴퓨터 공학부 (공학사) 2007년 2월: 충북대학교 전자공학과 (공학 석사) 2007년 3월 현재: 한양대학교 전자컴퓨 터통신 박사과정 2008년 7월 2012년 10월: (주)파인디지털 2012년 10월 현재: (주)아이티텔레콤 [주 관심분야] 가시광통신, 채널 추정, Wireless Access in Vehi2005 cle Environments 531