1、CEQT T/TR*04-03*E 85 W 2326414 O010652 4 W - G9 04-03 Page E 1 Recommendation T/TR 04-03 E (Nice 1985) concerning digital radio-relay systems with input Bit rates higher than the second hierarchical level in the 17.7 to 19.7 GHz band Recommendation proposed by Working Group T/TR 12 “Transmission” (T
2、R) Text of the Recommendation adopted by Commission “Telecommunication”: “The European Conference of Post and Telecommunication Administrations, Considering a) that the application of digital radio-relay systems operating in the 17.7 to 19.7 GHz band is foreseen in various b) that the radio-frequenc
3、y channel arrangement in the 17.7 to 19.7 GHz band has been recommended by the CCIR c) that limitation in the number of interfaces to be harmonized is desirable; and some constraints on the number d) that it is considered important that the recommended specifications should provide sufficient freedo
4、m for the use parts of telecommunications networks, usually without a protection channel; for 34, 140 and 2,140 Mbit/s systems; of particular equipment characteristics to be defined are necessary; of future technologies. e Recommends to the members of the CEPT to apply, at the time of planning digit
5、al radio-reIay systems with input bit rates of 34, 140 and 2,140 Mbit/s operating in the 17.7 to 19.7 GHz band, the specifications defined below. Edition of September 15, 1985 CEPT T/TR*04-03*E 85 6 232b414 001Ob53 b I SPECIFICATIONS 1. 2. 2.1. 2.2. 0 2.3. 2.4. 3. 4. 4.1. T/TR 04-03 E Page 3 INTRODU
6、CTION This specification includes equipment reguirements resulting from different equipment and system utilisa- tions foreseen by CEPT Administrations. Where possible, alternative requirements have been given to cover different utilisations. Two families of equipment are considered for 34 Mbit/s sys
7、tems (see Section 2.3.). For 140 Mbit/s, three systems categories are covered (see Section 4.1 .). GENERAL CHARACTERLSTICS RF Channel Arrangements The channelling arrangement given in Figure 1 of CCIR Recommendation 595 (1978-82) is adopted. Some Administrations need to take account of the use of 2
8、Mbit/s and 8 Mbit/s systems operating in this frequency band. The use of low capacity system is covered by Note 5 of CCIR Recommendation 595. Capacity The capacity included in this recommendation are: 34 Mbit/s 140 Mbit/s 2,140 Mbit/s Applications The following main applications are presently being
9、considered: a) short systems in urban areas for junction and distribution network requirements; b) short links from terminal radio stations to repeater stations or switching centres; c) digital traffic into each station. For 34 Mbit/s systems, two families of equipment are covered in this recommenda
10、tion: Family A systems are designed for all types of applications listed above with nominal hop lengths in the Range 8 to 15 km, depending on climatic conditions. Family B systems have less stringent technical requirements and are designed for use in junction and distribution networks (see item (a)
11、above) with hop lengths of up to about 5 to 8 km. The following has been agreed for all bit rates covered in this recommendation: i) When equipment of different origin and design are used on the same hop, different antennas or different polarizations on the same antenna will be used for each type of
12、 equipment. ii) Transmitters and receivers for one RF channel, in both directions of transmission and in hops in tandem, will be of the same origin and design. Types of Installation The types of installation will be indoor, outdoor or partially outdoor. Equipment with capacities of up to 140 Mbit/s
13、utilising outdoor installation will be usually housed in small cabinets and they should be tested according to the open air climatograms defined in Recommendation It is envisaged that for 2,140 Mbit/s systems equipment may also be housed in shelters with partial environment control. T/TR 02-06. RF B
14、LOCK DIAGRAMS The RF points A, B, C and A, B, C are shown in Figure 1. These points are reference points and not necessarily measuring points. GENERAL CHARACTERISTICS RELATING TO RF PARAMETERS Utilisation of the Channel Arrangement For 34 Mbit/s systems 2 types of utilisation of the channel arrangem
15、ent are foreseen as shown in Figure 2. Ouring to the limited number of channels usually employed on one hop, only one antenna may be used. 140 Mbit/s systems operating on the full utilisation of the channel arrangement as shown in Figure 3a (see also Figure lb of CCIR Recommendation 599, and on two
16、restricted utilisations, as shown in Figures 3b and c, are covered in this recommendation. -l Edition of September 15, 1985 I CEPT T/TR*04-03*E 5 = 2326434 0030654 T/TR 04-03 E Page 4 In the case of 2,140 Mbit/s systems, a full utilisation of the channel arrangement is considered in this recommendat
17、ion. The co-existence of channels with different capacities within the same hop is not covered by this specifica- tion. 4.2. Local Oscillator Frequency Arrangement Various Intermediate Frequencies (IF) can be used. In the case of utilisation of 70 MHz IF for 34 Mbit/s systems or 140 MHz IF for 140 M
18、bit/s systems, the following local oscillator frequency arrangements should be adopted : a) 34 Mbit/s systems, using a 70 MHz IF: - local oscillator frequencies higher than the nominal frequencies for Channels 1 to 18 and 1 to 18; - local oscillator frequencies lower than the nominal frequencies for
19、 Channels 19 to 35 and 19 to 35. - local oscillator frequencies higher than the nominal frequencies for Channels 1 to 4 and 1 to 4; - local oscillator frequencies lower than the nominal frequencies for Channels 5 to 8 and 5 to 8. In the case of 2,140 Mbit/s systems one solution is to utilise a singl
20、e oscillator both for the direct modulation transmitter and for the receiver local oscillator; the IF will then be 1,120 MHz. b) 140 Mbit/s systems, using a 140 MHz IF: 4.3. Limitation of Emitted Spectrum For 34 Mbit/s, 140 Mbit/s and 2,140 Mbit/s systems the power density referred to Point B or C s
21、hall be respectively within the masks shown in Figures 4a, b, and c. The level of spectrum lines at distances from the centre frequency equal to the symbol rate shall be at least 30 dB lower than the unmodulated carrier level. The measurement should be carried out frstly with unmodulated carrier and
22、 then with a pseudo-random bit sequence: F3 - 1 with a 30 kHz band width of the spectrum analyser. 4.4. Channel Identification Channel identification facilities are necessary to prevent, in the case of loss of wanted signal, the reception of other co-channel emissions that could be interpreted as a
23、correct signal. At least 2 different channel identifications are necessary. There are different methods for providing channel identification facilities and these shall be included in the radio equipment. 5. TRANSMITTER CHARACTERISTICS 5.1. Transmitter Output Power The nominal value of the output pow
24、er referred to B shall be between + 12 dBm and +23 dBm. The following reference values are given in order to determine the necessary receiver RF channel filter selectively in correspondence to the image frequency : + 16 dBm for 34 Mbit/s systems, +20 dBm for 140 Mbit/s and 2,140 Mbit/s systems. The
25、nominal values given above refer to the unmodulated condition. It may be required to reduce the output power for short hops, for example by excluding the RF amplifier and/or inserting RF attenuators. 5.2. Transmitter Radio Frequency Tolerance It is intended that equipment shall respect the limit for
26、 indoor applications when tested in accordance with Recommendation T/TR 02-03 and the limit for outdoor applications when tested in accordance with Recommendation T/TR 02-06, as appropriate. The maximum tolerance has to take into account the effect of the power density spectrum on adjacent channels
27、and other types of systems utilising the same frequency band. The frequency tolerance (including instability and initial inaccuracy) are: - for testing conditions applicable to indoor installation: - for testing conditions applicable to outdoor installation : This condition must be fulfilled by equi
28、pment enclosed in its own container, which may be optimised for different climatic conditions. 2 50. lo“, f80.10“. -. Edition of September 15, 1985 CEPT T/TR*Oq-O3*E 85 m 2326434 0030655 T W T/TR 04-03 E Page 5 5.3. Limitation of Spurious Signals Harmonics of the transmit frequency should be kept lo
29、w in compliance with the Radio Regulations. a) 34 Mbit/s Systems The following limits for the spurious signals in the 17.7-19.7 GHz band at reference Point B are given with reference to direct modulated transmitters and to measurements carried out in absence of modulation. Attenuation : 240 dB Level
30、 : -45 dBm at a frequency separation in the range of from 14 to 42 MHz from the nominal carrier - 75 dBm at a distance greater than 42 MHz from the nominal carrier frequency. (Note 1 .) In the case of IF modulation at 70 MHz, the following limits apply at the defined frequencies: -40 dBm at the tran
31、smitter heterodyne frequency; -60 dBm at a frequency separation of f70 MHz from the nominal carrier frequency (excluding the heterodyne frequency) ; -70 dBm at a frequency separation of f 140 MHz and f 210 MHz from the nominal carrier frequency, (Note 1.) b) 140 Mbit/s Systems The following limits f
32、or the spurious signals in the 17.7-19.7 GHz band at reference Point B are given with reference to direct modulated transmitters and to measurements carried out in absence of modulation. Attenuation : 240 dB Level : -45 dBm at a frequency separation in the Range 55 to 165 MHz from the nominal carrie
33、r frequency. -70 dBm at a distance greater than 165 MHz from the nominal carrier frequency. (Note 1.) In the case of 140 MHz IF modulation, the following limits apply at the defined frequencies: - 35 dBm at a transmitter heterodyne frequency; - 35 dBm at a frequency separation of f 140 MHz from the
34、nominal carrier frequency (excluding the - 65 dBm at a frequency separation of f 280 MHz and f 420 MHz from the nominal carrier frequency, c) 2,140 Mbit/s Systems The foilowing limits for the spurious signals have to be verified at reference Point B. Attenuation : 240 dB Level : -75 dBm at a distanc
35、e greater than 350 MHz from the nominal frequency. Note 1: This value has been defined to meet compatibility requirements in accordance with the harmonisation objectives. For equipment operating within the same branching network a Figure 15 dB more stringent is required. with respect to the unmodula
36、ted carrier, at a frequency separation in the range of from O to 14 MHz from the nominal carrier frequency. frequency. (Note 1.) with respect to the unmodulated carrier at a frequency separation in the Range O to 55 MHz from the nominal carrier frequency. heterodyne frequency); (Note I.) with respec
37、t to the unmodulated carrier at a frequency separation in the Range 0-110 MHz from the nominal carrier frequency. 6. RECETVER CHARACTERISTICS 6.1. Bit Error Ratio Characteristics and Receiver Input Level Range The BER, measured in accordance with CCITT Recommendation 0.151, with a pseudo-random bit
38、sequence F3 - 1, between interface points T and T on a simulated hop (with a flat variable attenuator), shall be 3.10-“ for receiver input levels from -30 dBm to -60 dBm for 34 Mbit/s systems: from -25 dBm to - 55 dBm for 140 Mbit/s systems; and from -20 dBm to -50 dBm for 2,140 Mbit/s systems. If s
39、ervice channels are transmitted by FM, the same performance shall be verified by applying a sinusoidal signal of the highest frequency used of the service channel(s) at a level of +25 dBmO (this signal has to be applied after the output of the service channel signal processor). For 34 Mbit/s systems
40、, the BER as a function of receiver input level shall comply with the curves shown in Figure 5a. Curve 1 applies to family A systems, and Curve 2 to family B systems, The BER as a function of the receiver input level shall comply with Figure 5b for 140 Mbit/s systems, and Figure 5c for 2,140 Mbit/s
41、systems. All the measurements are referred to the unmodulated carrier level and referred to Point B. Edition of September 15, 1985 7 CEPT T/TR*04-03*E 5 E 2326434 0030656 I W T/TR 04-03 E Page 6 When service channels are transmitted by FM, the measurement shall be carried out by applying a tone of t
42、he highest frequency used of the service channel(s) at an O dBmO level. Moreover, if the level of the tone is increased to 525 dBmO, the receiver input level corresponding to a BER of l.104 shall not increase by more than 4 dB. Receiver RF Channel Filter Selectivity The curves shown in Figures 5a, 5
43、b and 5c should be verified in the presence of interference from local transmitters, at the reference levels given in Section 5.1., around the image frequency. Degradation in BER Characteristics Due to Co-Channel and Adjacent Channel Interferences The following measurements shall be performed as def
44、ined in Sub-Section 6.1. with interfered and inter- fering carriers modulated with uncorrelated pseudo-random bit sequences F3 - 1. The interfering carriers shall have an emitted spectrum within the masks of Figures 4a, b and c respectively, for 34 Mbit/s and 140 Mbit/s and 2,140 Mbit/s systems. The
45、 interference criteria given for 34 Mbit/s systems under simulated fading conditions are related to the two families of system defined in Section 2.3. Item (a) should be respected if equipment of family A is required, or alternatively, item (b) if equipment of family B is sufficient. The interferenc
46、e criteria given for 140 Mbit/s systems are related to the three types of channel utilisation described in Figure 3. Item (a) should be respected if the full channel utilisation is required in one hop, and correspondingly, item (b), or (c), should be respected if the restricted utilisations of Figur
47、e 3b, or 3c, are sufficient. Note: These criteria are suitable to permit equipment designed exclusively for the restricted channel utilisations to interwork on the orthogonal polarisations of the same antenna in the following combinations: a+b a+c 6,2. 6.3. The combination of b and c on the same ant
48、enna is not covered by the same recommendation. Degradation Under Normal Propagation Conditions In respect of a Co-channel interference at a level -20 dB with respect to the interfered carrier. The BER shall be 63.10- for receiver input levels in the range -30 dBm to -60 dBm. If the service channel(
49、s) is transmitted by FM, the same performance shall be verified applying a sinusoidal signal of the highest frequency used for service channel(s) with a level of +25 dBmO. Three interference conditions are taken into account, (a) referring to a full utilisation of the channel arrangement shown in Figures 3a, (b) and (c) referring to the restricted utilisations shown respectively in Figures 3b and 3c. a) Co-channel interference at a level -20 dB with respect to the interfered carrier. Two adjacent channel interferences at a distance of + 110 MHz and - 110 MHz wi
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