ITU-R M 478-5-1995 Technical Characteristics of Equipment and Principles Governing the Allocation of Frequency Channels between 25 and 3000 MHz for the FM Land Mobile Service《调频陆地移.pdf
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1、RECOMMENDATION IT-R M.478-5* TECHNICAL CHARACTERISTICS OF EQUIPMENT AND PRINCIPLES GOVERNING THE ALLOCATION OF FREQUENCY CHANNELS BETWEEN 25 AND 3000 MHz FOR THE FM LAND MOBILE SERVICE (Question -R 7/8) (1970- 1974- 1978- 1982- 1990- 1995) Summary The rapid development of the different applications
2、of land mobile services in the frequency bands between 25 and 3 o00 MHz requires the recommendation of technical characteristics of FM equipment and principles governing the allocation of frequency channels. The analogue and digitized voice transmissions may share the same frequency bands and channe
3、ls with minimal interference between the systems. The Recommendation gives the preferred technical characteristics for VHF and UHF land mobile equipment using F3E class of emission, including the considerations of the necessary bandwidth, the transmitter, the receiver and the station characteristics
4、. The IT Radiocommunication Assembly, considering a) that certain technical characteristics of equipment and stations in the land mobile service are of importance in connection with radio interference between the stations of different countries; b) that agreement is desirable on certain technical ch
5、aracteristics of land mobile equipment, to minimize mutual interference and to facilitate the use of the same types of equipment in different countries in a geographical region; cl that agreement is desirable on the practices governing the choice of station antenna height and effective radiated powe
6、r taking into account geographical features, required communications range and system parameters; d) that agreement is desirable on the practices governing the allocation of channels in the land mobile service, in order to minimize mutual interference and to obtain economy of use of the frequency sp
7、ectrum; e) that in some areas, different values for the technical characteristics of equipment are required, in order to minimize mutual interference; 0 that the values agreed upon should be based on circumstances that typify high-density radio usage areas and should be a compromise between optimum
8、spectrum utilization and cost; g) that under some circumstances, e.g. where channel assignments and/or types of system operation permit, not ali recommended technical characteristics are required to minimize mutual interference; h) that in the land mobile service, ultimate spectrum utilization is de
9、termined by assignment techniques, suppression and rejection of unwanted radiation, and other means additional to the actual characteristics of the equipment; j) that there is a rapid development in methods of digitized voice and data transmission using various coding techniques; k) that analogue an
10、d digitized voice transmissions may share the same frequency band and channels with minimal interference between these systems; * This Recommendation should be brought to the attention of Radiocommunication Study Group 1. COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLicens
11、ed by Information Handling Services2 Maximum permissible frequency deviation (kH4 f4 ITU-R RECMN*M- 478-5 75 4855232 0524759 5T4 m Rec ITU-R M.478-5 Necessary bandwidth (kHz) 14 1) IT-R (former CCIR) of any methods of measurement applicable to radio equipment used in land mobile services; m) that, i
12、n Opinion ITU-R 42, the International Electrotechnical Commission (IEC) has been invited to advise the that Recommendation kU-R SM. 1045 provides advice on frequency stability requirements for future use, recommends that the preferred technical characteristics for VHF and UHF land mobile equipment u
13、sing F3E class of that Annex 2 should be taken into account, as appropriate, in the allocation of channels in the land mobile that reference should also be made to the IEC Publication 489 on methods of measurement (see Note 5 of 0 3 that reference should be made to Annex 3 for information on some ex
14、ample values if the 1500 MHz band is to 1 emission should be indicated in Annex 1 ; 2 service between 25 and 1 o00 MHz; 3 of Annex i); 4 be used. ANNEX 1 Preferred technical characteristics for VHF and UHF land mobile equipment using F3E class of emission 1 Necessary bandwidth The transmitter charac
15、teristics specified in 8 2 are based on the following assumption regarding the necessary bandwidth (see Note 4). 1.1 For class F3E 30 and 25 kHz channel separations: 16 kHz 20 kHz channel separation: I I I 12.5 and 15 kHz channel separation: 8.5 kHz or 11 kHz (see Note 5). NOTE 1 - Subsequent Class
16、A designations refer to alternative values and measurement methods which are specified in the United States of America telecommunications standard TIA/EIA-603. NOTE 2 - Subsequent Class E designations refer to alternative values and measurement methods which are specified in European telecommunicati
17、ons standard ETS 300 086. NOTE 3 -Where reference is not made to Classes A or E, the class(es) are in agreement with the preferred values. NOTE 4 - Necessary bandwidth: For a given class of emission, the width of the frequency band which is just sufficient to ensure the transmission of information a
18、t the rate and with the quality required under specified conditions (from the Radio Regulations (RR). NOTE 5 - Another value may be used by some administrations. Class A specifies 11 kHz for 12.5 kHz. COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLicensed by Information Han
19、dling ServicesITU-R RECMN*M- 478-5 75 4855232 0524960 23b Rec ITU-R M.478-5 Channel spacing (kHz) 20,25 and 30 12.5 3 35 MHz 80 MHz 160 MHz kHz() ppm kHz(l) ppm kHz() ppm 0.43 12 0.96 12 0.8 5 - - 1.0 12 0.8 5 2 Transmitter characteristics (kw Below 47 MHz 2.1 Frequency tolerance Within the temperat
20、ure ranges specified by each administration according to the environment, and for specified ranges of primary supply voltages, the frequency error of any carrier emission should not exceed the values given in Tables 1 or 2 (Class E only). Table 1 specifies the frequency tolerance in ppm. Above 137 A
21、bove 300 Above 500 to 300 MHz to 500 MHz to 1 O00 MHz 47-137 MHz TABLE 1 Preferred tolerances for each frequency band 20 and 25 I f 0.6 I f 1.35 f 2.00 I f 2.00 k 2.50() 300MHz I 450MHz 12.5 Table 2 applies to Class E equipment which specifies the frequency tolerance in units of kHz for the various
22、frequency bands. f 0.6 f 1.00 I 1.00 (B) f 1.00 (B) No value specified f 1.50 (M) I 1.50 (M)() TABLE 2 Class E frequency tolerances I Channel I Frequency error limit (kHz1 COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLicensed by Information Handling ServicesITU-R RECMN*N-
23、478-5 95 m 4855212 05249b1 L52 m 4 Rec ITU-R M.478-5 25 I30 20 2.2 Maximum permissible frequency deviation f 5.0 I4.0lf 5.0 The maximum permissible frequency deviation corresponding to the channel spacing should be the values given in Table 3. TABLE 3 Deviation limits Channel spacing OrHz1 Maximum p
24、ermissible frequency deviation OcHz1 r 12.51 15 I f 2.5 I 2.3 Adjacent channel power 2.3.1 25 and 30 kHz channel spacing 25-500 MHz: at least 70 dB below carrier power in a bandwidth of 16 kHz 500-1 O00 MHz: at least 65 dB below carrier power in a bandwidth of 16 kHz. (Class A specifies 70 dB to 512
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