1、 Report ITU-R F.2107-1(12/2009)Characteristics and applications of fixed wireless systems operating in the 57 GHz to 130 GHz bandsF SeriesFixed serviceii Rep. ITU-R F.2107-1 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the r
2、adio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed by World and Regional
3、 Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be used for the submissi
4、on of patent statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found. Series of ITU-R Repor
5、ts (Also available online at http:/www.itu.int/publ/R-REP/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mobile, radiodetermination, amateur and rela
6、ted satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management Note: This ITU-R Report was appro
7、ved in English by the Study Group under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2010 ITU 2010 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rep. ITU-R F.2107-1 1 REPORT ITU-R F.2107
8、-1 Characteristics and applications of fixed wireless systems operating in the 57 GHz to 130 GHz bands (2007-2009) Scope This Report contains propagation aspects, system design parameters, possible applications and other technical/operational characteristics, which are required for the implementatio
9、n of fixed wireless systems in the frequency ranges 57 GHz to 130 GHz. The applications include specific examples of outdoor/indoor wireless connections taking advantage of these frequency bands (i.e. 60 GHz (57-64 GHz), 70 GHz (71-76 GHz), 80 GHz (81-86 GHz), 95 GHz (92-95 GHz) and 120 GHz (110-130
10、 GHz). The example systems in the 120 GHz case study, actually cover systems in the 110-130 GHz band. It is intended that future versions of this Report would be needed. Vocabulary VCWL: Vertically-connected wireless link A wireless link providing a short vertical connection within a building, e.g.
11、between the rooftop and the balconies. Abbreviations ARO Availability ratio objective ARQ Automatic repeat request A/D Analog/Digital BBER Background block error ratio BER Bit error ratio BPSK Binary phase shift keying BSTV Broadcasting-satellite television DTTV Digital terrestrial television D/A Di
12、gital/Analog EPO Error performance objective ESR Errored second ratio FEC Forward error correction FPU Filed pick-up unit FWA Fixed wireless access HD-SDI High-definition serial digital interface HDTV High definition television HEMT High electron mobility transistor HRP Hypothetical reference path H
13、RX Hypothetical reference connection 2 Rep. ITU-R F.2107-1 IF Intermediate frequency IP Internet protocol MHEMT Metamorphic high electron mobility transistor MMIC Microwave monolithic integrated circuit MMW Millimeter wave MRC Maximum ratio combining LAN Local area network LoS Line-of-sight OC-192 O
14、ptical carrier-192 OFDM Orthogonal frequency division multiplexing OI Outage intensity PCMCIA Personal computer memory card international association PDA Personal digital assistant PRBS Pseudorandom bit sequence QAM Quadrature amplitude modulation QPSK Quatenary phase-shift keying RF Radio frequency
15、 SD Spatial diversity SESR Severely errored second ratio VCO Voltage controlled oscillator VCWL Vertically connected wireless link WLAN Wireless local area network WPAN Wireless personal area network 10GbE 10 Gigabit Ethernet References Recommendation ITU-R F.1497: Radio-frequency channel arrangemen
16、ts for fixed wireless systems operating in the band 55.78-59 GHz Recommendation ITU-R F.1668: Error performance objectives for real digital fixed wireless links used in 27 500 km hypothetical reference paths and connections Recommendation ITU-R F.1703: Availability objectives for real digital fixed
17、wireless links used in 27 500 km hypothetical reference paths and connections Recommendation ITU-R F.1704: Characteristics of multipoint-to-multipoint fixed wireless systems with mesh network topology operating in frequency bands above about 17 GHz Recommendation ITU-R P.530: Propagation data and pr
18、ediction methods required for the design of terrestrial line-of-sight systems Rep. ITU-R F.2107-1 3 Recommendation ITU-R P.676: Attenuation by atmospheric gases Recommendation ITU-R P.833: Attenuation in vegetation Recommendation ITU-R P.837: Characteristics of precipitation for propagation modellin
19、g Recommendation ITU-R P.838: Specific attenuation model for rain for use in prediction methods Recommendation ITU-R P.840: Attenuation due to clouds and fog Recommendation ITU-R P.1238: Propagation data and prediction methods for the planning of indoor radiocommunication systems and radio local are
20、a networks in the frequency range 900 MHz to 100 GHz Recommendation ITU-R P.1410: Propagation data and prediction methods required for the design of terrestrial broadband radio access systems operating in a frequency range from 3 to 60 GHz Recommendation ITU-R P.1411: Propagation data and prediction
21、 methods for the planning of short-range outdoor radiocommunication systems and radio local area networks in the frequency range 300 MHz to 100 GHz Report ITU-R F.2047: Technology developments and application trends in the fixed service Report ITU-R F.2060: Fixed service use in the IMT-2000 transpor
22、t network ITU-T Recommendation G.826: End-to-end error performance parameters and objectives for international, constant bit-rate digital paths and connections ITU-T Recommendation G.828: Error performance parameters and objectives for international, constant bit-rate synchronous digital paths 1 Int
23、roduction In recent years, the interest in the 57-130 GHz range for wireless communication applications has increased significantly. The main reason for this interest is the potential for wide bandwidth implementations which meet the growing requirement Correia and Prasad, 1997 for high data rate ap
24、plications in the range of hundreds of Mbit/s, including last-mile connectivity. Various short distance link configurations may be expected in these bands, including high-density applications. In Canada, the band 57-64 GHz is available for licence-exempt applications. In the United States of America
25、, the 60 GHz (57-64 GHz), 70 GHz (71-76 GHz), 80 GHz (81-86 GHz) and 95 GHz (92-95 GHz) bands are available for broadband wireless applications. In Japan, wireless personal area network (WPAN) systems are being implemented in the 60 GHz range for short-range, high-speed multimedia data services to t
26、erminals located in rooms or office space, and the feasibility experiments of 10 Gbit/s wireless links were conducted in the 120 GHz band (110-130 GHz). In Europe, several bands above 57 GHz are currently being considered for fixed wireless systems. In the United Kingdom, the 57-59 GHz band is avail
27、able for licence-exempt FS point-to-point applications and the 64-66 GHz, 71-76 GHz and 81-86 GHz bands are also available for point-to-point FS applications under a simple regulatory process. 4 Rep. ITU-R F.2107-1 2 Propagation characteristics and considerations in the 60/70/80/95/120 GHz bands Fre
28、e-space loss is proportional to the square of the operating frequency; therefore, the free-space loss in the 60/70/80/95/120 GHz bands is much higher than the losses in the 2.4 GHz or 5 GHz bands available in many administrations for WLAN operations. The free-space loss PLFS(dB) at a reference dista
29、nce d0(m) is given by: =0104log20dPLFS(1) where is the wavelength (m). The average path loss over a distance d (m) can be determined using the following path loss exponent model based on Recommendation ITU-R P.675 (ex-CCIR): +=0100log10)()(ddndPLdPLFS(2) where: :)(dPLthe average path loss (dB) at a
30、particular distance d n: the path loss exponent that characterizes how fast the path loss increases with transmit and receive antenna separation. Figure 1 shows the simulated results of the received signal level (dBm) as a function of the distance from the transmit antenna. The simulated results are
31、 provided for the 2.4/5.5/60/70/80/95/120 GHz bands. In this simulation, it is assumed the transmit power Ptis 10 dBm, the transmit and receive antenna gains (Gtand Gr) are unity, n is 2.1, and the oxygen absorption is 15 dB/km for the 60 GHz band and zero otherwise. FIGURE 1 Received power (dBm) vs
32、. distance (km) Report 2107-012.4 GHz70 GHz80 GHz95 GHz120 GHz5.5 GHz60 GHz (O2atten.)Distance between the transmit and the receive antennas (km)012 3452101901701501301109070Receivedpower(dBm)Gt Gr = = 1, Pt = 10 , exponent loss = 2.1, O attenuation 15 dB/km2Rep. ITU-R F.2107-1 5 From Fig. 1, the pa
33、th loss at 60 GHz is much higher than the losses at other frequency bands because of the oxygen absorption, which is detrimental to signal propagation. In an outdoor environment, the gaseous absorption attenuates the transmitted signal (10 to 15 dB/km) in addition to free-space loss. Notwithstanding
34、 the above, the oxygen absorption loss can be compensated for by the use of high-gain directive antennas. As well, it can also prove attractive for short-range communications as it further attenuates harmful interference such as co-channel interference in wireless cell-based systems, which combined
35、with low transmit powers in the 60 GHz band (10 mW) can increase frequency reuse from cell to cell. For the 70/80/95/120 GHz bands, the gaseous absorption is negligible. Figure 2 shows the attenuation (dB/km) vs. the frequency (GHz) due to the gasses and hydrometeors for radio transmission through t
36、he atmosphere. The figure indicates that rain has the greatest impact on transmitted signals in the 60/70/80/95/120 GHz bands. FIGURE 2 Attenuation due to gasses and hydrometeors for transmission through the atmosphere Therefore, enhancement of RF devices and techniques in these frequency bands woul
37、d improve the availability of these networks under rainy conditions. For indoor applications, transmitted signals in the 60/70/80/95/120 GHz bands are significantly attenuated by surrounding objects and inner walls and can result in a substantial drop in the received signal level. Additionally, meas
38、ured values of RF signal material attenuation have been published in Rappaport, 2002. The following results of minimum and maximum attenuation (57-95 GHz) through various materials have been interpolated from these findings: Fibreglass insulation: 3-3.5 dB Dry paper-towel: 3-3.5 dB Asphalt shingle:
39、3.5-4 dB Drywall: 3.5-6.5 dB Glass: 4.5-7 dB 6 Rep. ITU-R F.2107-1 Wet paper-towel: 5-7 dB 19 mm pine board: 8-11 dB 19 mm plywood: 7-11 dB Clay brick: 10-23 dB Painted 2 8 (5 cm 20 cm) board: 20-35 dB. There are also various ITU-R Recommendations that are useful in dealing with propagation issues a
40、t these frequencies (see References). Other factors such as delay spread and Doppler may also need to be taken into consideration. The delay spread is caused by reflections and scattering and will depend on the size of the room and the nature of the walls and objects in it. In a typical office (noma
41、dic) environment, the reflected signals may cause delay spread of the order of few tens of nanoseconds at 58 GHz Smulders and Wagemans, 1992 and subsequence intersymbol interference, depending on the symbol duration. This effect can be minimized by using directive antennas, which in turn complicate
42、other aspects such as broader coverage. Experimental results of vertical propagation characteristics in the 60 GHz band are given later in Appendix 1. 3 System design considerations for the 60/70/80/95/120 GHz bands In addition to the propagation medium, the performance of a wireless communication s
43、ystem also strongly depends on the hardware specifications of the transmitter, the receiver, and the antenna subsystems. Design parameters such as amplifier linearity, output power, noise figure, mixer conversion loss, oscillator phase noise, antenna gain, and antenna beamwidth influence the entire
44、system performance. In the millimetre-wave (mm-wave) bands, choosing the parameters mentioned-above is a challenging task because of their inter-dependencies. Trade-offs and compromises must be made to ensure a realistic design. Furthermore, the cost of the RF subsystems depends on the volumes of pr
45、oduction. As the volume increases, the cost per subsystem decreases. Therefore, for the 60/70/80/95/120 GHz systems to be competitive with systems operating at lower frequencies, the volume of the deployed systems needs to be very high. 3.1 Multiplexing and modulation schemes One of the efficient sc
46、hemes for transmission in the 60/70/80/95/120 GHz bands is the orthogonal frequency division multiplex (OFDM) scheme Heiskala and Terry, 2002, which enhances the systems spectrum efficiency and makes the propagation channel robust against large delay spread. In the case of OFDM systems, the phase no
47、ise of the local oscillators in the links transceivers is very critical and could impair the orthogonality of OFDM transmission. For 60/70/80/95/120 GHz systems, the carrier frequency is obtained by multiplying the frequency of the reference local oscillator whereby the phase noise at these frequenc
48、ies would be higher than in 2.4 GHz and 5.5 GHz systems. The increase in the systems phase noise leads to BER performance degradation, particularly when OFDM is used with higher order modulation techniques such as 16-QAM and 64-QAM Heiskala and Terry, 2002. Therefore, the phase noise of the local os
49、cillators for these mm-wave systems is a design challenge and requires design attention. The use of adaptive modulation makes the adaptation of a users data rate as a function of the channel conditions (average SINR, BER, etc.) possible Nanda et al., 2000 and Lin et al., 1984. Efficient adaptive modulation schemes must incorporate both robust transmission modes with low modulation efficiency such as BPSK or QPSK and high data rate modes with high modulation Rep. ITU-R F.2107-1 7 efficiency such as 64-QAM or 256-
