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
25、 MHz, and 60 dB from 5 12 MHz to 940 MHz. Class E specifies 70 dB from 500 MHz to 1 O00 MHz.) 2.3.2 20 IrHz channel spacing At least 70 dB below carrier power in a bandwidth of 14 kHz, Af =4 kHz (Af: the maximum permissible frequency deviation). At least 60 dB below carrier power in a bandwidth of 1
26、4 kHz, Af = 5 kHz (Af: the maximum permissible frequency deviation). 2.3.3 12.5 kHz channel spacing At least 60 dB below carrier power in a bandwidth of 8.5 kHz. (Class A specifies 50 dB from 512 to 940 MHz.) In each case, it is not necessary to reduce the adjacent channel power below 0.25 pW. (Clas
27、s A specifies 50 pW rather than 0.25 pW.) 2.4 Conducted spurious emissions Spurious emissions on discrete frequencies, when measured in a non-reactive load equal to the nominal output impedance of the transmitter, should not exceed 2.5 pW for transmitter carrier powers up to 25 W. For carrier powers
28、 in excess of 25 W, the level of any spurious emission should be at least 70 dB below the carrier power. (Class A specifies 50 pW rather than 2.5 pW. Class E specifies that any conducted spurious emissions should not exceed the values given in Table 4.) COPYRIGHT International Telecommunications Uni
29、on/ITU RadiocommunicationsLicensed by Information Handling Services ITU-R RECMN*M. 478-5 95 W 4855222 05249b2 O99 Rec. ITU-R M.478-5 Frequency range TABLE 4 Class E conducted spurious emissions Above 1 to 4 GHz or above 1 to 12.75 GHz() 9 kHz to 1 GHz 5 Tx standby (nW) 2.0 20.0 I Tx operating (pW) I
30、 0.25 I 1 .o0 I Frequency range 30 MHz to 1 GHz Above 1 to 4 GHz 2.5 Cabinet radiation The cabinet radiated power should not exceed 25 pW. The hand portable equipment should not exceed 2.5 pW. In some radio environments, a lower value may be required. (Class E specifies that cabinet radiation should
31、 not exceed the values given in Table 5.) TABLE 5 Class E cabinet radiation I TX operating (PW) I 0.25 I 1 .o0 I I Tx standby (nW) I 2.0 I 20.0 I 2.6 Attenuation of the intermodulation of base station transmitters In the case of multiple transmitters operation at a base station site, the attenuation
32、 of intermodulation, due to the non- linearities of the output stage of the transmitter, should be at least 20 dB. In some conditions even higher values of attenuation might be necessary and may be obtained by means of appropriate protection devices. (Class A and Class E both specify 40 dB using a m
33、ethod of measurement different from JEC 489.) 3 Receiver characteristics All parameters except the conducted spurious emissions and the cabinet radiation are not the subject of regulation in some countries (these specification may be mandatory for countries which regulate equipment using Class E sta
34、ndards). Measurements shall be performed using MUS (see Note 5). 3.1 Reference sensitivity The reference sensitivity should be less than 2.0 pV, e.m.f., for a given reference signal-to-noise ratio at the output of the receiver (see Note 1). 3.2 3.2.1 The adjacent channel selectivity should not be le
35、ss than 70 dB. (Some countries require not less than 65 dB for the frequency range 500-1 o00 MHz. Also, Class A specifies 60 dB for portable handheld equipment.) Adjacent channel selectivity (see Notes 1 and 2) 20,25 and 30 kHz channel spacing COPYRIGHT International Telecommunications Union/ITU Rad
36、iocommunicationsLicensed by Information Handling Services ITU-R RECMNwM. 478-5 95 4855212 O524963 T25 Limit (nW) 6 Rec. IW-R M.478-5 3.2.2 12.5 kHz channel spacing The adjacent channel selectivity should not be less than 60 dB (see Note 3). 3.3 Radio-frequency intermodulation (see Note 2) When measu
37、red using an interfering frequency combination of twice and four times the ch 2.0 20.0 nnel spacing separ: ed from the receiving frequency, the intermodulation response rejection ratio should not be less than 70 dB (see Notes 3 and 4). Frequency range Limit (pV/m) 3.4 Co-channel rejection When a wan
38、ted signal is applied in the presence of an interfering signal on the same frequency, the ratio of interference- to-signal is not less than -8 dB for 25 kHz channel spacing and not less than -12 dB for 12.5 kHz channel spacing. 30-88 MHz 88-2 16 MHz 216-960 MHz 960 MHz to 1 GHz 100 150 200 500 3.5 A
39、t any frequency separated from the nominal frequency of the receiver by more than one channel spacing, the spurious response rejection ratio should not be less than 70 dB. (Class A specifies 60 dB for handheld portables.) Spurious responses (see Note 2) 3.6 Conducted spurious emissions The power of
40、any spurious emission measured at the antenna terminals with matched termination, on any discrete frequency, should not exceed 2.0 nW. (Class A specifies 20 nW. Class E specifies that any conducted spurious emission should not exceed the values given in Table 6.) TABLE 6 Class E conducted spurious e
41、missions Frequency range I 9kHztolGHz I Above 1 to 4 GHz or above 1 to 12.75 GHd) 3.7 Cabinet radiation The effective radiated power of any spurious emission on any frequency from 25 MHz to lo00 MHz should not exceed 4.0 nW and from 1 O00 MHz to 3 000 MHz should not exceed 20 nW. (Class A specifies
42、this limitation as a field strength at a distance of 3 m as listed in Table 7. Class E specifies that any cabinet radiation should not exceed the values given in Table 8.) TABLE 7 Class A cabinet radiation (3 rn separation) COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLice
43、nsed by Information Handling ServicesITU-R RECMNxH. 478-5 95 m 4855232 0524964 961 m Rec. IT-R M.478-5 7 Frequency range 30 MHz to 1 GHz Limit (nW) 2.0 TABLE 8 Above 1 to 4 GHz 20.0 NOTE 1 -Class E specifies a measurement method which uses 20 dB SINAD and 6 dB degradation, and a psophometric filter.
44、 NOTE 2 - Class E specifies the measurement use SUS (see Note 5). NOTE 3 - Some countries require at least 65 dB for the frequency range 500-1 O00 MHz. Class A specifies 50 dB for handheld portable equipment, and Class E specifies 65 dB for mobile and handheld portable. NOTE 4 - Class A and Class E
45、both specify that measurement frequencies should be the combination of 50 and 100 kHz displaced from the reference frequency. NOTE 5 - (Measured Usable Sensitivity) MUS and (Specified Usable Sensitivity) SUS are defined in IEC Doc. 12F(S) 216 which has been approved to be the draft international sta
46、ndard (DIS). Methods of measurement for the radiation at frequencies exceeding 1 GHz are in preparation for the revision of IEC Publication 489. 4 Station characteristics 4.1 Frequency characteristics 4.1.1 Radio-frequency band of operation According to the Table of Frequency Allocations contained i
47、n RR Article 8; in particular the bands of 35, 80, 160, 300, 450,800 and 900 MHz. 4.1.2 Separation of the transmit and receive frequencies for full duplex operation 35 MHz band: 4 MHz 80 MHz band: 3 MHz 160 MHz band: 3 MHz 300 MHz band: 4 MHz 450 MHz band: 5 MHz The above are practical minimum value
48、s determined by cost and isolation required; smaller separations are possible using higher quality and more costly duplexers. 800 MHz band: 45 or 55 MHz 900 MHz band: 39 or 45 MHz This preferred value is determined by the desirability to provide for high-capacity systems with a great number of chann
49、els. However, in some systems, greater transmitheceive frequency separation might be required. In practice, the actual separations used may be other than the values given and may be determined by other factors than were used in this Recommendation. Frequencies should preferably be assigned with a constant separation between the transmit and receive frequencies over the whole of a band or the subbands within a band. 4.2 It is recognized that the responsibility for limiting the effective radiated power and antenna height over the average level of the ground rests with admin
