1、 Rec. ITU-R F.1760 1 RECOMMENDATION ITU-R F.1760 Methodology for the calculation of aggregate equivalent isotropically radiated power (a.e.i.r.p.) distribution from point-to-multipoint high-density applications in the fixed service operating in bands above 30 GHz identified for such use*(2006) Scope
2、 This Recommendation provides a methodology which may be used to derive the a.e.i.r.p. for transmitting point-to-multipoint (P-MP) and multipoint -to-multipoint (MP-MP) high-density applications in the fixed service (HDFS) stations in bands above 30 GHz which may be used by administrations wishing t
3、o assess the potential interference from P-MP HDFS stations to other services. The ITU Radiocommunication Assembly, considering a) that an estimate of the aggregate equivalent isotropically radiated power (a.e.i.r.p.) from a deployment of point-to-multipoint (P-MP) high-density applications in the f
4、ixed service (HDFS) stations may be required by administrations to assess the potential interference from P-MP HDFS stations to other victim services on a national and bilateral basis; b) that using automatic transmitter power control (ATPC) in P-MP transmitters would reduce the aggregated radiated
5、power; c) that the determination of a.e.i.r.p. could be improved by considering the topology, demographic data and deployment model within the defined area, recognizing 1 that No. 5.547 of the Radio Regulations (RR) identifies the bands 31.8-33.4 GHz, 37-40 GHz, 40.5-43.5 GHz, 51.4-52.6 GHz, 55.78-5
6、9 GHz and 64-66 GHz as being available for high-density applications in the fixed service (HDFS), noting a) that Resolution 75 (WRC-2000) invites ITU-R to develop, as a matter of urgency, the technical basis for determining the coordination area for the receiving earth station in the space research
7、service (deep space) with HDFS transmitting stations in the 31.8-32.3 GHz and 37-38 GHz bands; b) that Resolution 79 (WRC-2000) invites ITU-R to conduct studies on the coordination distance between radio astronomy stations operating in the 42.5-43.5 GHz band and HDFS systems, recommends 1 that the m
8、ethodology described in Annex 1 may be used to determine the a.e.i.r.p. distribution from transmitting P-MP HDFS stations operating in bands above 30 GHz. *This Recommendation also applies to multipoint -to-multipoint (MP-MP) high-density applications in the fixed service (HDFS). 2 Rec. ITU-R F.1760
9、 Annex 1 Methodology for the calculation of aggregate equivalent isotropically radiated power (a.e.i.r.p.) distribution from P-MP high-density applications in the fixed service operating in bands above 30 GHz 1 Introduction Resolution 75 (WRC-2000) requests the development of the technical basis for
10、 determining the coordination area for coordination between receiving earth stations in the space research service (deep space) and transmitting stations of high-density applications in the fixed service (HDFS), in the 31.8-32.3 GHz and 37-38 GHz frequency bands. In addition, Resolution 79 (WRC-2000
11、) invites ITU-R to conduct studies on the coordination distance between radio astronomy stations operating in the 42.5-43.5 GHz band and HDFS systems. This Recommendation provides methodologies which may be used to derive the a.e.i.r.p. for transmitting P-MP HDFS stations which may be used by admini
12、strations wishing to assess the potential interference from P-MP HDFS stations to other victim services in their national and bilateral discussions. The methodologies in this recommendation may be used as a basis for further study by administrations wishing to answer the resolves under Resolutions 7
13、5 (WRC-2000) and 79 (WRC-2000). WRC-2000 adopted the RR 5.547 that identified certain bands above 30 GHz to be available for high-density applications in the fixed service. System specific characteristics are not identified, but it is expected that large numbers of terminals would be deployed within
14、 specified areas associated with traditional fixed service systems. These high density fixed service (P-MP HDFS) systems may have hundreds of terminals within a cell, and may consist of thousands of cells. This could give rise to a significant aggregation of e.i.r.p., and new approaches must be cons
15、idered to model such effects. One such approach, presented in the methodology below, is to determine the distribution of aggregate equivalent isotropically radiated power (a.e.i.r.p.) from P-MP HDFS stations dispersed over a defined area called a building block (BB). The a.e.i.r.p. takes into accoun
16、t: variation in transmitter and receiver heights; variation in station location and hop length; variation in antenna azimuth and associated gain towards a point on the horizon; variation in transmit power control. These parameters can be convolved using an interference equation and Monte Carlo simul
17、ation to produce a distribution of a.e.i.r.p. at a receiving test point located on the horizon. Using this method, each cell can be modelled as an a.e.i.r.p. distribution that represents potentially large numbers of transmitters within the area defined by the BB. The methodology is defined in three
18、stages: Stage 1 definition of P-MP HDFS system parameters; Stage 2 deployment model; Stage 3 convolution of system parameters to obtain the a.e.i.r.p. distribution. These stages are described in the sections below, and an example application is presented in Appendix 1. Rec. ITU-R F.1760 3 1.1 Use of
19、 Monte Carlo simulation In order to calculate the a.e.i.r.p. distributions it is necessary to take into account the variation in input parameters, such as station locations and antenna azimuths. This can be done using a statistical modelling approach, such as a Monte Carlo methodology. The Monte Car
20、lo methodology is based on the principal of sampling random variables from their defined probability distributions. These distributions are defined in terms of maximum and minimum system parameters when defining the P-MP HDFS reference system (see 3.2 below). In order to get statistically meaningful
21、 results, a suitable number of samples are required when using the Monte Carlo approach. To determine the a.e.i.r.p. distributions, at least 10 000 samples should be taken. 1.2 Types of P-MP HDFS network A number of architectures could be used to provide P-MP HDFS services. Two such are point-to-mul
22、tipoint (P-MP) and multipoint-to-multipoint (MP-MP). Figure 1 shows the elements of a P-MP system. FIGURE 1 Elements of P-MP network The architecture comprises: an area defined as the cell over which service is provided; at a location within this cell, typically the centre, is located the base stati
23、on (BS); the cell is divided into a set of sectors, with service provided for each by a separate antenna; within each sector are located user terminals (UT)s; each UT has an antenna that points at the BS. Note that a cell can consist of a single sector. Figure 2 shows the elements of a MP-MP system.
24、 4 Rec. ITU-R F.1760 FIGURE 2 Elements of MP-MP network The architecture comprises: an area over which service is provided; each node or user terminal (UT) is connected to at least one other; additional UTs can be connected to existing nodes. 2 Description of a.e.i.r.p. distribution methodology 2.1
25、Stage 1 P-MP HDFS system parameters The first stage is to define the P-MP HDFS system parameters. This can be done using the template Table 1. TABLE 1 P-MP HDFS model parameters Parameter Value Units Comment Architecture User specified Either P-MP or MP-MP Transmitter User specified Specify whether
26、BS, UT or MP-MP Tx antenna radiation pattern User specified Tx peak antenna gain User specified dBi Tx height (above terrain): Min height Max height User specified User specified m m For P-MP systems, specify max height only. For MP-MP systems, antenna height selected at random between min and max v
27、alue Number of cells User specified No. cells modelled for P-MP systems within BB size Number of sectors per cell User specified Default is 1 for MP-MP systems Rec. ITU-R F.1760 5 TABLE 1 (end) Parameter Value Units Comment Number of users/sector or number of transmitting nodes User specified Specif
28、y number of simultaneously transmitting users, or MP-MP nodes User location within sector Random Selected at random Link path length: Min length Max length User specified User specified km km Path length selected at random between min and max value. For P-MP systems the UT position is random within
29、the sector. Frequency 43 GHz Default value Reference bandwidth B 1 MHz Default value ATPC used Yes/No Max Tx power Min Tx power User specified User specified dB(W/B MHz)dB(W/B MHz) If ATPC not used, Tx power varied at random between min and max value within the reference bandwidth B MHz Nominal Rx i
30、nput level User specified dB(W/B MHz) If ATPC is used, set Tx power to achieve nominal Rx input level within the reference bandwidth B MHz Other losses User specified dB Feeder and cable losses etc Receiver User specified Specify whether BS, UT or MP-MP Rx antenna radiation pattern User specified Rx
31、 peak antenna gain User specified dBi Rx height (above terrain): Min height Max height User specified User specified m m For P-MP systems, specify max height only. For MP-MP systems, antenna height selected at random between min and max value 2.2 Stage 2 Deployment model The second stage is to defin
32、e the BB or reference area over which the P-MP HDFS stations will be deployed, and the location of the test points used to determine the a.e.i.r.p. on horizon. The BB or reference area is defined as a constant area such as a rectangle of size 4 km 4 km. Other references areas can be considered, but
33、the value selected must be consistent with how the a.e.i.r.p. is used. Within the BB area will be located a specified number of P-MP cells or MP-MP nodes. The number of P-MP cells will depend upon cell size. So a BB of size 4 km 4 km could contain one large cell or four smaller cells. The horizon te
34、st points are located every x around a circle (where x Max TX power then set PTX= Max TX power. Step 18: If PTXMax TX power then set PTX= Max TX power. Step 18: If PTX Min TX power then set PTX= Min TX power. Step 19: Calculate e.i.r.p. from this transmitter in direction of TPiusing: pTXoTXjiLGPEIRP
35、 +=,. Step 20: Increment AEIRP for this sample with this e.i.r.p.: 10/)()(,10jiEIRPWiWiAEIRPAEIRP + . Rec. ITU-R F.1760 9 Step 21: When all transmitters have been included, convert AEIRP(W)into dBW: )(log10)(10)( WidBWiAEIRPAEIRP = . Step 22: Increment relevant bin in AEIRP array using AEIRPi(dBW) S
36、tep 23: When Nmaxsteps have been completed, output AEIRP array as histogram and/or CDF. Key to equations: As above for P-MP. 2.3.3 Adjustments to model The objective is to determine the a.e.i.r.p. in terms of dBW within a reference bandwidth such as 1 MHz. This could also be the mean a.e.i.r.p. for
37、this reference bandwidth integrating over a larger, victim receiver bandwidth (e.g. 1 GHz). The calculations above therefore could require adjustment to scale to the required value. The reference area may contain multiple P-MP HDFS cells, depending on cell type and environment. For P-MP deployment i
38、t will be necessary to determine: the number of active sectors that operate co-frequency; the number of user terminals per sector; hence, determine the number of active users per sector that operate co-frequency. An adjustment must be made to take account of the total power from all P-MP HDFS channe
39、ls that can be accommodated within the bandwidth of the receiving earth station, scaled to the reference bandwidth of 1 MHz. )(log1010 channelsNAdj = (3) where: DLBwULBwRxBwchannelsHDFSHDFSESN+= where: Adj: required adjustment Nchannels: number of channels that can be accommodated with the bandwidth
40、 of the receiving earth station ESRxBw: bandwidth of receiving earth station HDFSULBw: bandwidth of P-MP HDFS station in uplink direction HDFSDLBw: bandwidth of P-MP HDFS station in downlink direction. 2.3.4 Output from the methodology The output from the methodology will be a histogram and/or cumul
41、ative distribution function (CDF) of the a.e.i.r.p. distribution. 10 Rec. ITU-R F.1760 Appendix 1 to Annex 1 Example application of the a.e.i.r.p. distribution methodology 1 Introduction This Appendix presents an example application of the a.e.i.r.p. distribution methodology described in Annex 1 usi
42、ng parameters of a European FS system, assuming no clutter loss and free space propagation. 2 Example application to urban commercial symmetric deployment The methodology has been applied to a P-MP system deployed in an urban commercial environment operating with symmetric transmission bandwidths be
43、tween the BS and UT. The a.e.i.r.p. distribution has been obtained for the uplink direction, i.e. UT to BS. 2.1 System parameters Using the P-MP HDFS system template, the parameters of the UCS system are shown in Table 1. TABLE 1 P-MP UCS parameters Parameter Value Units Architecture P-MP Transmitte
44、r UT Tx antenna radiation pattern Bessel Tx peak antenna gain 33.1 dBi Tx height (above terrain): Min height Max height N/A 5 M m Number of cells 4 Number of sectors per cell 4 Number of users/sector or number of transmitting nodes 136 User location within sector Random Link path length: Min length
45、Max length N/A 1.4 km km km Frequency 43 GHz Reference bandwidth 1 MHz Rec. ITU-R F.1760 11 TABLE 1 (end) Parameter Value Units ATPC used Yes Max Tx power Min Tx power 30 70 dB(W/MHz) dB(W/MHz) Nominal Rx input level 124.1 dB(W/MHz) Other losses 1 dB Receiver P-MP BS Rx antenna radiation pattern EN
46、301 215-C2 Rx peak antenna gain 15 dBi Rx height (above terrain): Min height Max height N/A 20 m m 2.2 Deployment model The UCS stations are deployed within the reference area, which is defined as a constant area of size 4 km 4 km. From the parameters defined in Table 1, four cells are modelled (i.e
47、. four base stations) each with four sectors per cell. There are 136 users per sector. Figure 1 shows the UCS deployment model while Fig. 2 shows the location of the horizon test points calculated using equation (1) of 2.2 of Annex 1. FIGURE 1 Example UCS distribution 12 Rec. ITU-R F.1760 FIGURE 2 L
48、ocation of horizon test points 2.3 Calculation of a.e.i.r.p. distribution The following adjustments are made to the algorithm specified in Annex 1 to take into account the number of channels that can be allocated within the bandwidth of the receiving earth station. Receiving earth station bandwidth:
49、 1 000 MHz P-MP HDFS UL bandwidth: 28 MHz P-MP HDFS DL bandwidth: 28 MHz Nchannels: 17 From equation (3): Adj = 10 log10(17): 12.3 dB 2.4 Output from the methodology The a.e.i.r.p. histogram and cumulative distribution function for the UCS UT deployment are shown in the Fig. 3. FIGURE 3 Histogram and CDF distributions for the UCS user terminals
