THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. 2016 Sep.; 27(9), 783 790. http://dx.doi.org/10.5515/kjkiees.2016.27.9.783 ISSN 1226-3133 (Print) ISSN 2288-226X (Online) 5G A Study on the Effective Usage of mmwave Bands for 5G Backhaul Links 강영흥 Young-heung Kang 요약 30 GHz 300 GHz (mmwave) 5G (backhaul). WRC-19 1.13 24.25 86 GHz IMT, (femtocell). FCC,, 5G. Abstract Since scarcity of spectrum in future mobile networks, millimeter wave frequencies from 30 GHz to 300 GHz have been proposed to be used in an important part of 5G mobile communication backhaul links to provide several giga bits services. In ITU-R has been invited to conduct and complete in time for WRC-19 the appropriate studies to determine the spectrum needs for the terrestrial component of IMT in the frequency range between 24.25 GHz and 86 GHz. Also, small cells such as a femtocell, and heterogeneous networks have been deployed through world in order to enhance the communication capacity. At this stage, it is important to develop millimeter wave frequencies to provide 5G mobile broadband services, and thus this paper proposes the effective usage of these frequencies by summarizing the FCC allocation of millimeter waves, their propagation characteristics, the required minimum path length, and the interference effect. Key words: 5G, Backhaul, Millimeter Wave, Path Length, Interference. 서론. 5 (5G). 30 GHz 300 GHz (mm- Wave) HDTV(High Definition Television) UHDV (Ultra-High Definition Video) 5G KCA (KCA -2015-16) (R7719-16-1097). (School of Computer, Information and Communication Engineering, Kunsan National University) Manuscript received June 1, 2016 ; Revised July 7, 2016 ; Accepted September 6, 2016. (ID No. 20160601-03S) Corresponding Author: Young-heung Kang (e-mail: yhkang@kunsan.ac.kr) c Copyright The Korean Institute of Electromagnetic Engineering and Science. All Rights Reserved. 783
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 27, no. 9, Sep. 2016. [1]. ITU-R WRC-19 Item 1.13 Resolution 238 (WRC-15) 1 (primary services) IMT 24.25 86 GHz IMT. LTE WiMAX 4 (4G) bits/s/hz OFDM(Orthogonal Frequency Division Multiplexing), MIMO(Multiple Input Multiple Output),,,, HARQ(Hybrid Automatic Repeat Request). (femtocell) (heterogeneous networks). [2]. 28 GHz, 38 GHz, 60 GHz, E (71 76 GHz 81 86 GHz). CMOS(Complementary Metal-Oxide Semiconductor) RF IC [3], (mesh network) WPAN(Wireless Personal Area Network) WLAN(Wireless Local Area Network) ECMA-387, IEEE 802.15.3c, IEEE 802.11ad [3]., 30 GHz,.,, 160 180 db 99.999 % (availability) 42 GHz 3 km, 70/80 GHz 2 km., 5G., M/W (, 2.4 GHz 5 GHz) 5G, MAC,.,,. (C-ITS, Gigabit Wi-Fi ) 5G IMT,,. FCC,,.. 밀리미터파스펙트럼 3 300 GHz 1, 252 GHz,,. 57 64 GHz 15 db/km, 164 200 GHz db. FCC (market) 1(b) A 27.5 28.35 GHz, 29.1 29.25 GHz, 31.075 31.225 GHz 1.15 GHz, B 31.0 31.075 GHz, 31.225 31.3 GHz 150 MHz. 2003 FCC E- 71 76 GHz, 81 86 GHz, 92 95 GHz P-P WLAN,,, 1(c) E- 784
5G 백홀 링크를 위한 밀리미터파 대역의 효율적 이용에 관한 연구 3-2 침투성 및 기타 손실 3 300 GHz 주파수에서 대기가스 손실과 강우 감쇠는 수증기 및 강우 흡수 대역을 제외하고, km 당 수 db 이하 이며, 반사 및 회절에 기인하는 손실은 물질과 표면에 상 당히 의존한다. 비록 반사 및 회절에 의해 밀리미터파의 전송거리가 줄어들지만, NLOS(Non-Line-Of-Sight) 통신에 는 유용하다. 밀리미터파 신호는 높은 레벨의 감쇠에 의 해 외부 및 기지국으로부터 빌딩 실내로 전파수신이 차 단될 수 있다. 이 경우, 실내 커버리지는 실내 밀리미터파 펨토셀 또는 Wi-Fi 방법을 통해 제공될 수 있으며, 60 GHz 밀리미터파를 사용하는 차세대 Wi-Fi 기술이 이미 IEEE 802.11ad에서 개발되고 있다. 밀리미터파는 나뭇잎에 의한 손실은 중요하며, 그 전 파손실의 예를 그림 2(a)에 나타낸다. 여기서 80 GHz, 10 (a) (b) [5] (c) 밀리미터파 스펙트럼 [2] 그림 1. Fig. 1. Millimeter wave spectrum[2]. 총 12.9 GHz 대역폭이 가능하다. E-대역의 높은 지향성의 "펜실빔(pencilbeam)" 신호특성은 상호간섭 없이 근접시 키는 기술이 가능하므로 FCC 등은 이 대역에서 "라이트 라이선싱(light licensing)"을 도입하고 있다. [2] Ⅲ. 전파특성 나뭇잎 통과특성 (a) (a) Foliage penetration characteristics 3-1 자유공간 전파 밀리미터파의 전송손실은 근본적으로 자유공간 손실 에 의해 크게 좌우된다. 대형의 개구면적을 갖고 있는 안 테나는 무선파로부터 많은 에너지를 수신하기 때문에, 작 은 개구면적의 안테나보다 더욱 큰 이득을 얻는다. 그러 나 파장이 짧아지면 동일 개구면적으로 많은 에너지를 수신할 수 있으므로, 다수의 안테나들은 높은 이득의 송 수신기 빔포밍(beamforming)을 가능하게 한다. 예를 들어 안테나 면적이 일정할 때, 80 GHz에서의 빔은 2.4 GHz 에서의 빔보다 30 db 이상의 이득(협대역 빔)을 가지게 된다. [4] 강우감쇠특성 (b) (b) Rain attenuation characteristics 밀리미터파 전파특성 [2] 그림 2. [2] Fig. 2. Propagation characteristics of millimeter wave. 785
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 27, no. 9, Sep. 2016. m 23.5 db 3 GHz 15 db.,, 2(b) [6]., 2.5 mm/h 1 db/km, 150 mm/h db/km. 3-3 도플러및다중경로 3 350 km/h 3 60 GHz 10 20 khz. MMB(Millimeter-wave Mobile Broadband),, (non-zero), (AFC: Automatic Frequency Control). MMB.. PDP(Power Delay Profile) RMS(Root Mean Square) 1 10 ns, (coherent) 10 100 MHz. MMB, MMB, [2].. 최소경로길이기준 5 GHz,. [7] ITU. 11.7 GHz ITU-R 35 %(8 km). 15.2 GHz, 18.7 GHz, 23.2 GHz 30 %(3 km), 29 %(2 km), 40 %(2 km). 5G. 13 km, 47 CFR Part 101 Fixed Microwave Services [11] P-P M/W 10 GHz 17 km 10 GHz 5 km.,,. [12]. P-P 1.5 58 GHz, [13]. 1. 표 1. [km] Table 1. Comparison of the required minimum path lengths [km]. Frequency [GHz] 1.350 1.517 30.0 3.600 4.200 24.5 5.925 7.125 16.0 7.425 7.900 15.5 GB Australia US Korea 20.0 17.0 12.75 15.35 9.50 5.0 5.0 17.70 23.60 4.0 24.50 26.80 3.0 37.00 39.50 1.0 2.0 N/A 13.0 786
5G 5-1 간섭시나리오. 간섭분석.. 3 (BC: Backhaul Center), (edge). (omni), TDD (slot), [8]. CEPT ITU ITU-R Rec. P.452-14 [9]., (clutter)., (rural), (suburban), (urban), (dense urban) (nominal distance). 5-2 최소분리거리 db 그림 3. Fig. 3. Interference scenario between backhaul sectors. 표 2. Table 2. Parameters for interfering and interfered source. [GHz] 28 28 Tx [dbm] 18 0 Tx and Rx [dbi] 40 0 [MHz] 28 20 [db] 6 0 [m] 20 50 1.5 그림 4. I/N Fig. 4. I/N from directional antenna in macrocell backhaul. 2. ITU-R Rec. 699-7 [10] I/N 4. (main beam) (back lobe) I/N. I/N 6 km I/N=0 db, 3 km I/N= 60 db 50 db. 5., e.i.r.p.=30 db, 5 m 20 m 787
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 27, no. 9, Sep. 2016. 그림 5. Fig. 5. Minimum separation distance with receive antenna height., 25 km 220 km 200 km,.. 효율적이용방안 ITU-R WRC-19 Item 1.13 Resolution 238 (WRC-15) (primary services) IMT. 24.25 86 GHz IMT 24.25 27.5 GHz, 37 40.5 GHz, 42.5 43.5 GHz, 45.5 47 GHz, 47.2 50.2 GHz, 50.4 52.6 GHz, 66 76 GHz 31.8 33.4 GHz, 40.5 42.5 GHz, 47 47.2 GHz. ITU-R 24.25 86 GHz 2 5G IMT. 5G, 5G IMT. [14] NLOS (throughput)., 100 Mbps 5.8 GHz 400 Mbps 28 GHz 20 db.., ITU 40 GHz FS (Fixed Service) (segment) 3 GHz, RF (, 70/80 GHz 1 GHz ) [8]. Gbps, NLOS., 1 8 GHz 15.5 km 12 16 GHz 5 9.5 km, 17 GHz 1 4 km., [7] 8 GHz 15 km, 12 16 GHz 5 km, 17 GHz 2 3 km. 5G. 28 GHz 5G P-MP. I/N, 788
5G I/N (main beam) (back lobe) I/N... 5G, (coordination area).. 결론 6 GHz M/W 6 GHz 30 GHz,. 10 GHz 83 %, 10 GHz 90 %, 30 GHz,. ITU,,. 13 km 12 GHz 15.5 km, 15 17 GHz 5 km, 17 GHz 2 3 km. 5G.,, (coordination area). References [1] M. Elkashln, T. Q. Duong, and H. H. Chen, "Milimeterwave communications for 5G: fundamentals: Part I [Guest Editorial]", IEEE Commun. Mag., vol. 52, no. 9, pp. 52-54, 2014. [2] F. Khan, Z. Pi, "Millimeter wave mobile broadband systems", IEEE Commun. Mag. vol. 49, no. 6, pp. 101-107, Jun. 2011. [3] T. S. Rappaport, J. N. Murdock, and F. Gutierrez, "State of the art in 60-GHz integrated circuits and systems for wireless communications", Proceedings of the IEEE, vol. 99, no. 8, pp. 1390-1436, Aug. 2011. [4] D. M. Pozer, Microwave Engineering, 3rd ed., Wiley, 2005. [5] E. Perahia et al., "IEEE 802.11ad: Defining the next generation multi-gb/s Wi-Fi", 2010 7th IEEE Consumer Commun. and Next Conference, Jan. 2010. [6] ITUR P.838-3, "Specific model for rain for use in prediction methods", 2005. [7], " M/W ",, 19(6), pp. 607-613, 2015 12. [8], "M/W ",, 2015 12. [9] ITU-R Rec. P.452-14, Prediction procedure for the evaluation of interference between stations on the surface of the Earth at frequency above 0.1 GHz, 2009. [10] ITU-R Rec. F.699-7, Reference radiation patterns for fixed wireless system antennas for use in coordination studies and interference assessment in the frequency 789
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 27, no. 9, Sep. 2016. range from 100 MHz to about 70 GHz, 2006. [11] FCC, 47 CFR Part 101-Fixed Microwave Services. [12] RA, UK radio interface requirement 2000, Feb. 2002. [13] ACA, Microwave radio spectrum trends: accommodating the demands of growth, new technologies and relocation, Feb. 2000. [14] Ericsson Review, Non-line-of-sight microwave backhaul for small cells, Feb. 2013. 1984 2 : ( ) 1986 2 : ( ) 1993 2 : ( ) 1988 3 1990 2 : 1995 8 1996 8 : 2003 8 2005 2 : York 1990 4 : [ 주관심분야 ],,,, USN 790