1、H 3404583 0078490 O46 Released: July 1, 1993 GSM 03.30 Version 4.2.0 Date: July 1993 Work Item No: Key words: European digital cellular telecommunication system (phase 2); Radio Network Planning Aspects ETSI European Telecommunications Standards institute ETSI Secretariat: F - 06921 Sophia Antipoiis
2、 Cedex. France TP. + 33 92 94 42 00 TF. + 33 93 65 47 16 Tx. 47 00 40 F This is an unpublished work the copyright in which vests in the European Teiecommunicatims Standards Institute. Ail rights reserved. The information contained herein is the propetry of ETSI and no pari may be reproduced or used
3、except as authorised by contract or other written permission. The copyright and the foregoing restriction on reproduction and use extend to all media in which the information may be embodied. M 3404583 007847L T82 a Page 3 GSM 03.30 (4.2.0): July 1993 Contents 1.scope 5 2 . Traffic distributions . 5
4、 2.1 Uniform . 5 2.2 Non-uniform . 5 3, Cell coverage 5 3.1 Location probability . 5 3.2 Ec/No threshold . 5 3.3 RF-budgets . 6 3.4 Cell ranges . 6 3.4.1 Large cells . 6 3.4.2 Small cells . 7 3.4.3 Microcells 8 4 . Channel reuse . 9 4.1 C/lc threshold 9 4.2 Trade-off between Ec/No and CAc . 9 4.3 Ad
5、jacent channel suppressions 9 4.4 Antenna patterns 10 4.5 Antenna heights . 10 4.6 Path loss balance 10 4.7 Cell dimensioning 1 0 4.8 Channel allocation . 10 4.9 Frequency hopping . 11 4.1 O Cells with extra long propagation delay 11 5 . Propagation models . 11 5.1 Terrain obstacles 11 5.2 Environme
6、nt factors. 11 5.3 Field strength measurements 12 5.4 Cell adjustments 12 6.Glossa ry . 12 7 . Bibliography . 13 Appendix A . 1 (class 4): Example of RF-budget for GSM MS handheld RF-output peak power 2 W 14 Appendix A.2 (class 2): Example of RF-budget for GSM MS RF-output peak power 8 W . 15 Append
7、ix A.3 (DCS1800 classes 1 A.l for GSM 900 MS class 4; A.2 for GSM 900 MS class 2, A.3 for DCS 1800 MS classes 1 and 2, and A.4 for GSM 900 class 4 in small cells. The antenna gain for the hand portable unit can be set to O dBi due to loss in the human body as described in CCIR Rep. 567. An explicit
8、body loss factor is incorporated in Appendix A.3 At 900 MHz, the indoor loss is the field strength decrease when moving into a house on the bottom floor on 1.5 m height from the street. The indoor loss near windows ( 1 m) is typically 12 dB. However, the building loss has been measured by the Finnis
9、h PlT to vary between 37 dB and -8 dB with an average of 18 dB taken over all floors and buildings (Kajamaa, 1985). See also CCIR Rep. 567. At 1800 MHz, the indoor loss for large concrete buildings was reported in COST231 TD(90)117 and values in the range 12 - 17 dB were measured. Since these buildi
10、ngs are typical of urban areas a value of 15 dB is assumed in annex A.3. In rural areas the buildings tend to be smaller and a 1 O dB indoor loss is assumed. The isotropic power is defined as the RMS value at the terminal of an antenna with O dBi gain. A quarter- wave monopole mounted on a suitable
11、earth-plane (car roo9 without losses has antenna gain 2 dBi. An isotropic power of -1 13 dBm corresponds to a field strength of 23.5 dBuV/m for 925 MHz and 29.3 dBuV/m at 1795 MHz, see CEPT Rec. T/R 25-03 and GSM 05.05 Section 5 for formulas. GSMSOO BTS can be connected to the same feeders and anten
12、nas as analog 900 MHz BTS by diplexers with less than 0.5 dB loss. 3.4 Cell ranges 3.4.1 Large cells In large cells the base station antenna is installed above the maximum height of the surrounding roof tops; the path loss is determined mainly by diffraction and scattering at roof tops in the vicini
13、ty of the mobile ie the main rays propagate above the roof tops; the cell radius is minimally 1 km and normally exceeds 3 km. Hatas model and its extension up to 2000 MHz (COST231-Hata model) can be used to calculate the path loss in such cells (see COST 231 T (90) 1 19 Rev 2 and Appendix B). The fi
14、eld strength on 1.5 m reference height outdoor for MS including handheld is a value which inserted in the curves of CCIR Rep. 567-3 Fig. 2 (Okumura) together with the BTS antenna heighi and effective radiated power (ERP) yields the range and reuse distance for urban areas (Section 5.2). The cell ran
15、ge can also be calculated by putting the maximum allowed path loss between isotropic antennas into the Figures 1 to 3 of Appendix C. The same path loss can be found in the RF-budgets in Appendix A. The figures 1 and 2 (GSM90O) in Appendix C are based on Hatas propagation model which fits Okumuras ex
16、perimental curves up to 1500 MHz and figure 3 (DCS 1800) is based on COST231 -Hata model according to COST 231 TD (90) 1 19 Rev 2. The example RF-budget shown in Appendix A.l for a GSMSOO MS handheld output power 2 W yields about double the range outdoors compared with indoors. This means that if th
17、e cells are dimensioned for handhelds with indoor loss 10 dB, the outdoor coverage for MS will be interference limited, see Section 4.2. Still more extreme coverage can be found over open flat land of 12 km as compared with 3 km in urban areas outdoor to the same cell site. For GSM 900 the Max EIRP
18、of 50 W matches MS class 2 of max peak output power 8 W, see Appendix A.2. An example RF budget for DCS1800 is shown in Appendix A.3. Range predictions are given for 1 W and 250 mW DCS1800 MS with BTS powers which balance the up and down- links. 340q583 0078495 628 D Page 7 GSM 03.30 (4.2.0): July 1
19、993 - Rural Rural (Open Area) (Quasi-Open) Base station 60 60 height (m) The propagation assumptions used in Appendix Al, A2, A3 are showri in the tables below : For GSM 900 : Rural Rural Urban (Open Area) (QSi-Open) Base station height (m) Mobile height (m) 1.5 95.7+31.8log(d) 123.3+33.71og(d) form
20、ula (d in km) Indoor Loss (dB) 10 10 15 For DCS 1800 : r Mobile height (m) 1.5 1.5 1.5 COST 231 1 00.1+33.3Iog(d) 105.1 +33.31og(d) 133.2+33.8109 (d) Hatas loss formula (d in km) I I Indoor Loss (dB) 10 10 15 (*) medium sized city and suburban centres (see COST 231 T3 (90) 11 9 Re. For metropolitan
21、centres add 3 dB to the path loss. Note 1 : The rural (Open Area) model is useful for desert areas and the rural (Quasi-Open) for countryside. Note 2 : The correction factors for Quasi-open and Open areas are applicable in the frequency range 100-2000 MHz (Okumura,l968). 3.4.2 Small cells For small
22、cell coverage the antenna is sited above the median but below the maximum height of the surrounding roof tops and so therefore the path loss is determined by the same mechanisms as stated in section 3.4.1. However large and small cells differ in terms of maximum range and for small cells the maximum
23、 range is typically less than 1-3 km. In the case of small cells with a radius of less than 1 km the Hata model cannot be used. The COST 231 -Walfish4 kegami model (see Appendix B) gives the best approximation to the path loss experienced when small cells with a radius of less than 5 km are implemen
24、ted in urban environments. It can therefore be used to estimate the BTS ERP required in order to provide a particular cell radius (typically in the range 200 m - 3 km). The cell radius can be calculated by putting the maximum allowed path loss between the isotropic antennas into figure 4 of Appendix
25、 C. 3404583 0078496 564 m GSM 03.30 (4.2.0): July 1993 The following parameters have been used to derive figure 4 : Width of the road, w = 20 m Height of building roof tops, Hroof = 15 m Height of base station antenna, Hb = 17 m Height of mobile station antenna, Hm = 1.5 m Road orientation to direct
26、 radio path , Phi = 90“ Building separation, b = 40 m For GSM 900 the corresponding propagation loss is given by : Loss (dB) = 132.8 + 38lq(d/km) For DCS 1800 the Corresponding propagation loss is given by : Loss (dB) = 142.9 + 3Iog(d/km) for medium sized cities and suburban centres Loss (dB) = 145.
27、3 + 381og(d/km) for metropolitan centres An example of RF budget for a GSM 900 Class 4 MS in a small cell is shown in Appendix A.4. 3.4.3 Microcells COST 231 defhes a microcell as being a cell in which the base station antenna is mounted generally below roof top level. Wave propagation is determined
28、 by diffraction and scattering around buildings ie. the main rays propagate in street canyons. COST 231 proposes the following experimental model for microcell propagation when a free line of sight exists in a street canyon : Path loss in dB (GSM 900) = 1 01.7 + 26log(d/km) d 20 m Path loss in dB (D
29、CS 1800) = 107.7 + 261og(d/km) d 20 m The propagation loss in microcells increases sharply as the receiver moves out of line of sight, for example, around a street corner. This can be taken into account by adding 20 dB to the propagation loss per corner, up to two or three corners (the propagation b
30、eing more of a guided type in this case). Beyond, the complete COST231 -WaMsh-lkegami model as presented in appendix B should be used. Microcells have a radius in the region of 200 to 300 metres and therefore exhibit different usage patterns from large and small cells. They can be supported by gener
31、ally smaller and cheaper BTSs. Since there will be many different microcell environments, a number of microcell BTS classes are defined in GSM 05.05. This allows the most appropriate microcell BTS to be chosen based upon the Minimum Coupling Loss expected between MS and the microcell BTS. The MCL di
32、ctates the close proximity working in a microcell environment and depends on the relative BTS/MS antenna heights, gains and the positioning of the BTS antenna. In order to aid cell planning, the micro-BTS class for a particular installation should be chosen by matching the measured or predicted MCL
33、at the chosen site with the following table. The microcell specifications have been based on a frequency spacing of 6 MHz between the microcell channels and the channels used by any other cell in the vicinity. However, for smaller frequency spacings (down to 1.8 MHz) a larger MCL must be maintained
34、in order to guarantee successful close proximity operation. This is due to an increase in wideband noise and a decrease in the MS blocking requirement from mobiles closer to the carrier. 3404583 0078497 4TO Page 9 GSM 03.30 (4.2.0): July 1993 Micro-BTS class Small freq. spacing Operators should note
35、 that when using the smaller frequency spacing and hence larger MCL the blocking and wideband noise performance of the micro-BTS will be better than necessary. Operators should exercise caution in choosing the microcell BTS class and transmit power. If they depart from the recommended parameters in
36、05.05 they risk compromising the performance of the networks operating in the same frequency band and same geographical area. 4. Channel re-use 4.1 C/lc threshold The C/ic threshold is the minimum cechanne1 carrier-to-interference raiio in the active part of the timeslot at the minimum service quali
37、ty when interference limited. The reference threshold C/ic = 9 dB includes 2 dB implementation margin on the simulated residual BER threshold1 The threshold quality varies with logical channels and propagation conditions, see GSM 05.05. 4.2 Trade-off between Ec/No and C/ic For planning large cells t
38、he service range can be noise limited as defined by Ec/No plus a degradation margin of 3 dB protected by 3 dB increase of CAC, see Appendix A. For planning small cells it can be more feasible to increase Ec/No by 6 dB corresponding to an increase of C/ic by 1 dB to cover shadowed areas better. C/(I+
39、N) = 9 dB represents the GSM limit performance. To permit handheld coverage with 1 O dB indoor loss, the Ec/No has to be increased by 1 O dB outdoors corresponding to a negligible increase of C/ic outdoors permitting about the same interference limited coverage for MS including handhelds. The range
40、outdoors can also be noise limited like the range indoors as shown in Section 3.4 and Appendix A.l. 4.3 Adjacent channel suppressions Adjacent channel suppression (ACS) is the gain (idic) in C/i when wanted and unwanted GSM RF- signals co-exist on adjacent RF channels whilst maintaining the same qua
41、lity as in the co-channel case, .e. ACS = = C/lc - C/la. Taking into account frequency errors and lading conditions in the product of spectrum and filter of wanted and unwanted GSM RF-signals, ACS = 18 dB is typical as can be found in GSM 05.05. 1st ACS = 18 dB, .e. Clal = 18 dB gives an acceptable
42、handover- margin of = 6 dB for signalling back to the old BTS as shown in GSM 05.08. An exception might be adjacent cells using the same site due to uplink interference risks. 2nd ACS = 50 dB, .e. Cba2 25 dB, backscattering from the main lobe must be suppressed by using an antenna height of at least
43、 1 O m above forward obstacles in ca 0.5 km. In order to achieve an omni-directional pattern with as few nulls as possible, the ideal non- directional antenna must be isolated from the mast by a suitable reflector. The nulls from mast scattering are usually in different angles for the duplex frequen
44、cies and should be avoided because of creating path loss imbalance. The main lobe antenna gains are typically 12-18 dBi for BTS, and 2-5 dBi for MS. Note that a dipole has the gain O dBd = 2 dBi. 4.5 Antenna heights The height gain under Rayleigh fading conditions is approximately 6 dB by doubling t
45、he BTS antenna height. The same height gain for MS and handheld from reference height 1.5 m to 10 m is about 9 dB, which is the correction needed for using CCIR Rec. 370. 4.6 Path loss balance Path loss balance on uplink and downlink is important for two-way communication near the cell edge. Speech
46、as well as data transmission is dimensioned for equal quality in both directions. Balance is only achieved for a certain power class (Section 3.4). Path loss imbalance is taken care of in cell selection in idle mode and in the handover decision algorithms as found in GSM 05.08. However, a cell dimen
47、sioned for 8 W MS (GSM 900 class 2) can more or less gain balance for 2 W MS handheld (GSM 900 class 4) by implementing antenna diversity reception on the BTS . 4.7 Cell dimensioning Cell dimensioning for uniform traffic distribution is optimised by at any time using the same number of channels and
48、the same coverage area per cell. Cell dimensioning for non-uniform traffic distribution is optimised by at any time using the same number of channels but changing the cell coverage area so that the traffic carried per cell is kept constant with the traffic density. Keeping the path loss balance by d
49、irectional antennas pointing outwards from the trac : peaks the effective radiated power (ERP) per BTS can be increased rapidly out-wards. In order to mahhti the inner cells really small the height gain can be decreased and the antenna gain can be made stnaller or even negative in dB by increasing the feeder loss but keeping the antenna front-to-back ratio cmstant (Section 4.4). 4.8 Channel allocation Channel allocation is normally made on an FDMA basis. However, in synchronised networks channel allocation can be made on a TDMA basis. Note that a BCCH RF channel must
