1、Rec. ITU-R SM.1447 1 RECOMMENDATION ITU-R SM. 1447 MONITORNG OF THE RADIO COVERAGE OF LAND MOBILE NETWORKS TO VERLFY COMPLIANCE WITH A GIVEN LICENCE* (Question ITU-R 21511) (2000) The ITU Radiocommunication Assembly, considering a) TDMA, FDMA) is increasing worldwide; that the number of land mobile
2、networks using different modulation types and access techniques (CDMA, b) conditions that networks must fulfil certain requirements including: - that in order to ensure efficient use of the spectrum, some administrations may specify in their licence geographical coverage, either in terms of route co
3、verage, surface coverage, population coverage, or also possibly indoor coverage in public and/or private places - train stations, underground railways, malls, buildings in office districts, etc., minimum field strength values for different mobile terminals, - - minimum sensitivity level (system-spec
4、ific), - maximum BER values, - channel impulse response (CIR), - CIZratio; cl land mobile services define the coverage area; d) operation of the station and to prevent interference to licensed stations; e) been developed to determine surface radio coverage, and to some extent indoor coverage; f) par
5、t of an international connection; g) that, in the case of cellular radio systems, cellular interference becomes more common due to frequency reuse and use of adjacent channel in nearby cells, which may cause intolerable CIZ in given areas, so that field strength measurements only may not always suff
6、ice to assess effective coverage; h) that present technology relying on multichannel reception and adaptive space diversity techniques makes it possible to carry out a detailed characterization of the reception conditions from a moving vehicle, including identification of the best server base statio
7、n, and of the possible interfering Co-channel and adjacent channel base stations (or traffic channels), measurement of the channel impulse response, and estimates of the BER; j) the network, or if it is caused by signals from another network or from other sources, and to decide corrective actions; k
8、) monitored measurements, that the minimum field strengths required for satisfactory reception of the different classes of emission in the that administrations may be interested in verifying compliance with licence conditions, to ensure appropriate that surface and indoor coverage cannot be measured
9、 everywhere so that simulation tools are needed and have that a degree of standardization is desirable, since the land mobile service connected to the PSTN may form that the identification of interfering stations is essential to decide whether interference is due to poor design of that identificatio
10、n and call signs are required in the licence, to compare the spectrum management data to the * This Recommendation should be brought to the attention of Radiocommunication Study Group 8 and Telecommunication Development Study Group 2. 2 Rec. ITU-R SM.1447 noting a) utilizing digital terrain maps; th
11、at it might be appropriate to use field strength planning and simulation tools to predict radio coverage, b) different organizations; that in some countries, licensing of public telecom services and spectrum licensing may be performed by cl by administrations, that in a number of countries the follo
12、wing recommended measurements are carried out by operators and not recommends that in the event an administration wishes to monitor the radio coverage of land mobile networks to verify compliance with a given licence the following be applied: 1 and simulation tools, an example of which is given in A
13、nnex 1; that a common set of technical parameters should be used to determine radio coverage using both measurement 2 the following procedures and methods: that radio coverage be measured, simulated, and checked against licence or authorization terms according to 2.1 monitoring stations should be us
14、ed to monitor coverage at given points and along routes; 2.2 reasonable number of places and at various floor levels, especially in case of towers; if indoor coverage is also to be checked, portable equipment should be used to take measurements at a 2.3 parts of the coverage area should be recorded
15、with position data, preferably together with the BER and centre frequency; the field strength of the signal at given places andor along a route which goes through the various significant 2.4 accuracy for the surface (or indoor) coverage may be estimated; recorded field strength values should be stat
16、istically compared to the calculated values, so that the simulation 2.5 simulated coverage area maps should be validated if measurements statistically agree with calculated values. Typical criteria for a simulation in a rural area could be I4 dl3 in 90% of measurements, and in urban areas I6 dl3 in
17、80% of measurements; 2.6 - significant discrepancies between measured and calculated values should be dealt with by successively: checking the validity of the simulation: - either the environment data used by the model (especially the digital terrain model and clutter information) need to be updated
18、 or replaced by a more accurate source, or it can be considered accurate enough; either confidence in the model has been built with previous measurements of a well specified test transmitter, so that other causes of discrepancies need to be found or the global model validity needs to be reassessed,
19、and the model recalibrated or changed; - - checking by remote measurement and then possibly in situ measurements the base station parameters - in particular position and altitude, power and antenna gain (e.i.r.p.) and antenna height; 2.7 be determined either from measurements or simulation results a
20、nd interfering stations should be identified; areas, where Co-channel, adjacent channel or external interference deteriorates the effective coverage, should 2.8 coverage of land mobile services should preferably be measured in conditions similar to the conditions encountered by the sub-user, e.g. wi
21、th an antenna mounted on the rooftop of a vehicle. In that case, measurements are less repeatable (than if made at a higher antenna level), due to the geometry of the vehicle and its accessories and the configuration of nearby vehicles in the flow of road traffic. However, they better reflect actual
22、 conditions of propagation encountered by the sub-users. Field strength should be measured along the route travelled by the measurement vehicle with sufficient resolution to obtain valid statistics on its behaviour. Several methods are possible, such as: - using short measurement samples so that pea
23、k and mean values of the field strength could be derived; as an example, for a vehicle travelling at 50 km/h in an urban area, 1 O00 measurements per second correspond to about 7 samples per wavelength travelled (3 GHz signal), which is a reasonable value; Rec. ITU-R SM.1447 3 - using longer integra
24、tion times, such as several hundred milliseconds or one second, which would result in loss of detailed statistics on the signal, but would still give valuable information on the average field strength level; 2.9 identification of base stations under investigation may be required. ANNEX 1 Common set
25、of technical parameters that determine radio coverage through measurement and simulation Administrations may choose the main parameters to be registered in the spectrum management database or the elements to be monitored. The main emission characteristics that determine the radio coverage of mobile
26、networks are: - - e.i.r.p. or typical and maximum output powers of transmitters, together with antenna characteristics (gain, The main siting characteristics of the station that determine the radio coverage of mobile networks are: - - The equipment characteristics for the various land mobile service
27、s which may be specified by administrations are: - for all systems: carrier frequency, bandwidth and modulation, polarization, feeder and coupling loss). coordinates and altitude above main sea level, altitude above ground level*, azimuth* and elevation* angles of the antenna. - channelling plan, -
28、receiver sensitivity*, - Co-channel and adjacent channel protection ratios*, - for digital systems: - BER for recommended quality level. The main emission characteristics that can be objectively measured to determine the radio coverage of mobile networks are: - frequency, - field strength*, - - NOTE
29、 1 -Measured parameter to assess objective quality of the coverage, and to be related to both the BER for the recommended quality level and to subjective measurements. Co-channel and adjacent channel interference levels* and identification of interfering stations*, BER (see Note i) in case of digital systems. * Parameter to be used for simulation purposes. Measured parameter to be compared with value given by simulation. *
