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1、BRITISH STANDARD BS EN 60835-2-9:1997 BS 7573-2.9: 1997 IEC 835-2-9: 1995 Methods of measurement for equipment used in digital microwave radio transmission systems Part 2: Measurements on terrestrial radio-relay systems Section 2.9 Service channels The European Standard EN 60835-2-9:1995 has the sta
2、tus of a British Standard ICS 33.060.30 Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 09:41:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 60835-2-9:1997 This British Standard, having been prepared under the direction of the Electrotechnical Sector Board, was published under the author
3、ity of the Standards Board and comes into effect on 15 January 1997 BSI 11-1998 The following BSI references relate to the work on this standard: Committee reference EPL/12/5 Draft for comment 91/29838 DC ISBN 0 580 26392 4 Committees responsible for this British Standard The preparation of this Bri
4、tish Standard was entrusted by Technical Committee EPL/12, Radio communication, to Subcommittee EPL/12/5, Radio communication systems, upon which the following bodies were represented: British Broadcasting Corporation British Radio and Electronic Equipment Manufacturers Association British Telecommu
5、nications plc ERA Technology Ltd. Institution of Electrical Engineers Radio, Electrical and Television Retailers Association Radiocommunications Agency Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 09:41:20 GMT+00:00 2006, Uncontrolle
6、d Copy, (c) BSI BS EN 60835-2-9:1997 BSI 11-1998i Contents Page Committees responsibleInside front cover National forewordii Foreword2 Text of EN 60835-2-93 List of referencesInside back cover Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 09:41:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI
7、BS EN 60835-2-9:1997 ii BSI 11-1998 National foreword This British Standard has been prepared by Subcommittee EPL/12/5 and is the English language version of EN 60835-2-9:1995 Methods of measurement for equipment used in digital microwave radio transmission systems Part 2: Measurements on terrestria
8、l radio-relay systems Section 9: Service channels, published by the European Committee for Electrotechnical Standardization (CENELEC). It is identical with IEC 835-2-9:1995, published by the International Electrotechnical Commission (IEC). BS EN 60835 is published in three Parts. The other Parts are
9、: Part 1: Measurements common to terrestrial radio-relay systems and satellite earth stations. Part 3: Measurements on satellite earth stations. Some of the many Sections of the three Parts have appeared under the number BS 7573, of the same generic title. This Section of BS EN 60835 deals with meas
10、urements pertaining to the service channels used in digital microwave radio-relay systems. Cross-references Publication referred toCorresponding British Standard BS EN 60835 Methods of measurement for equipment used in digital microwave radio transmission systems BS EN 60835-1 Measurements common to
11、 terrestrial radio-relay systems and satellite earth stations EN 60835-1-2:1993BS EN 60835-1-2:1995 Basic characteristics (IEC 835-1-2:1992) EN 60835-1-3:1995BS EN 60835-1-3:19971) Transmission characteristics (IEC 835-1-3:1992) EN 60835-1-4:1995BS EN 60835-1-4:19971) Transmission performance (IEC 8
12、35-1-4:1992) EN 60835-2-4:1995BS EN 60835-2 Measurements on terrestrial radio-relay (IEC 835-2-4:1993)systems BS EN 60835-2-4:19971) Transmitter/receiver including modulator/demodulator A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standa
13、rds are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 2 to 14, an inside back cover and a
14、 back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. 1) In preparation Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 09:41:20 GMT+00:00 2006, Uncontrolled Copy, (c)
15、 BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 60835-2-9 December 1995 ICS 33.060.30 Descriptors: Telecommunications, radiocommunications, communication equipment, digital technics, radio-relay systems, microwave frequencies, transmission channels, measurements English version Methods of
16、measurement for equipment used in digital microwave radio transmission systems Part 2: Measurements on terrestrial radio-relay systems Section 9: Service channels (IEC 835-2-9:1995) Mthodes de mesure applicables au matriel utilis pour les systmes de transmission numrique en hyperfrquence Partie 2: M
17、esures applicables aux faisceaux hertziens terrestres Section 9: Voies de service (CEI 835-2-9:1995) Meverfahren fr Gerte in digitalen Mikrowellen Funkbertragungssystemen Teil 2: Messungen an terrestrischen Richtfunksystemen Hauptabschnitt 9: Dienstkanle (IEC 835-2-9:1995) This European Standard was
18、 approved by CENELEC on 1995-11-28. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such
19、 national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own la
20、nguage and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden,
21、 Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1995 Copyright reserved to CENELEC members Ref. N
22、o. EN 60835-3-6:1995 E Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 09:41:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 60835-2-9:1995 BSI 11-1998 2 Foreword The text of document 12E/246/DIS, future edition 1 of IEC 835-2-9, prepared by SC 12E, Radio-relay and fixed satellite communicat
23、ion systems, of IEC TC 12, Radiocommunications, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60835-2-9 on 1995-11-28. The following dates were fixed: Annexes designated “normative” are part of the body of the standard. Annexes designated “informative” are given fo
24、r information only. In this standard, annex ZA is normative and annex A is informative. Annex ZA has been added by CENELEC. Contents Page 1General3 1.1Scope3 1.2Normative references3 2Analogue interface of service channels transmitted by analogue techniques3 2.1Return loss3 2.2Input deviation sensit
25、ivity3 2.3Output deviation sensitivity4 2.4Transmit-receive section parameters4 3Analogue interface of service channels transmitted by digital techniques5 3.1Return loss5 3.2Amplitude-frequency characteristic5 3.3PCM coder overload point5 3.4Idle channel noise6 3.5Total distortion including quantizi
26、ng distortion6 4Digital interface of service channels transmitted by digital techniques6 4.1Return loss, terminal balance ratio6 4.2Acceptability of the signal at the input of the transmit code converter6 4.3Level and shape of the signal at the output of the receive code converter7 4.4Effect of jitt
27、er7 Annex A (informative) Bibliography13 Annex ZA (normative) Normative references to international publications with their corresponding European publications14 Figure 1 Method of service channel transmission over a digital radio-relay system8 Figure 2 Measurement of peak-to-peak deviation in case
28、of sinusoidal modulation using a spectrum analyzer9 Figure 3 Back-to-back connection of transmit-side and receive-side multiplex equipment10 Figure 4 Test arrangement for measuring the signal-to-total distortion ratio11 Figure 5 Test arrangement for measuring the acceptability of the signal at the i
29、nput of the transmit code converter11 Figure 6 Test arrangement for measuring the level of the signal at the output of the receive code converter12 latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement(dop) 1996-09-01 l
30、atest date by which the national standards conflicting with the EN have to be withdrawn (dow) 1996-09-01 Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 09:41:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 60835-2-9:1995 BSI 11-19983 1 General 1.1 Scope This section of IEC 835-2 deals with
31、measurements pertaining to the service channels used in digital microwave radio-relay systems. In digital radio-relay systems, two basic methods are commonly used for the transmission of service channel signals (that is voice, supervisory and control signals) (see annex A, ref. 6). The first transmi
32、ssion method uses analogue transmission techniques where the i.f. or r.f. carrier signal of the digital modulator is directly frequency-modulated by the analogue service channel signal, which is then recovered at the receive end by an f.m. demodulator (for example in the carrier recovery circuit of
33、a coherent digital demodulator). In the second method of transmission, digital transmission is used and the service channel signal is transmitted in the form of separate bits inserted into the main bit stream by a multiplexer (possibly together with a bit stream carrying additional information). For
34、 digital transmission, the service channel signal may be either an analogue signal which is digitally encoded for bit insertion or a digital signal, in which case suitable code conversion is normally applied in order to convert the line code into a code suitable for the radio equipment. At the recei
35、ve end, a demultiplexer is used to recover the service channel bits and thus supply, after suitable decoding or code conversion, the service channel output signal. Normally, more than one service channel is transmitted. Sometimes an additional bit stream (for example alarm control signals for protec
36、tion switching and supervisory equipment) may also be transmitted. Suitable multiplexing and demultiplexing equipment is then used, such as frequency division multiplexing for analogue transmission, and time division multiplexing for digital transmission. The use of time division multiplexing also a
37、llows the simultaneous digital transmission of analogue and digital service channel signals. Figure 1 shows the simultaneous application of all the above possible service channel transmission systems. However, in a given radio-relay link, only one or two of these systems is used at a time. 1.2 Norma
38、tive references The following normative documents contain provisions which, through reference in this text, constitute provisions of this section of IEC 835-2. At the time of publication, the editions indicated were valid. All normative documents are subject to revision, and parties to agreements ba
39、sed on this section of IEC 835-2 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. IEC 835-1-2:1992, Methods of measurement for equipment
40、 used in digital microwave radio transmission systems Part 1: Measurements common to terrestrial radio-relay systems and satellite earth stations Section 2: Basic characteristics. IEC 835-1-3:1992, Methods of measurement for equipment used in digital microwave radio transmission systems Part 1: Meas
41、urements common to terrestrial radio-relay systems and satellite earth stations Section 3: Transmission characteristics. IEC 835-1-4:1992, Methods of measurement for equipment used in digital microwave radio transmission systems Part 1: Measurements common to terrestrial radio-relay systems and sate
42、llite earth stations Section 4: Transmission performance. IEC 835-2-4:1993, Methods of measurement for equipment used in digital microwave radio transmission systems Part 2: Measurements on terrestrial radio-relay systems Section 4: Transmitter/receiver including modulator/demodulator. 2 Analogue In
43、terface of service channels transmitted by analogue techniques 2.1 Return loss See IEC 835-1-2. 2.2 Input deviation sensitivity 2.2.1 Definition The input deviation sensitivity, Sm, of a frequency modulator, for a sinusoidal signal with a given frequency, is expressed as the ratio of the frequency d
44、eviation, f, to the baseband voltage, Vb, at the input of the service channel, i.e.: Sm = f / Vb kHz/V Vb and f are both expressed in either peak or r.m.s, values. The deviation sensitivity of the modulator is a function of the baseband frequency if a pre-emphasis network is applied. Licensed Copy:
45、sheffieldun sheffieldun, na, Sat Nov 11 09:41:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 60835-2-9:1995 4 BSI 11-1998 2.2.2 Method of measurement The service channel input port is driven by a sinusoidal signal with an input level and frequency producing the specified nominal deviation. The r.f
46、. output port of the transmitter is connected, via a suitable r.f. attenuator, to a down converter which converts the frequency of the r.f. output signal to the i.f. range, and a deviation meter is connected to the i.f. output of the down converter. The down converter and deviation meter are both co
47、mmercially available items of equipment. The reading of the deviation meter is noted, and the deviation sensitivity is calculated as the ratio of the deviation to the input level. A simple alternative method can be applied if the modulation index is large enough, for example if f is 70 kHz and modul
48、ation frequency is 1 kHz. On a spectrum analyzer with calibrated frequency axis, the f.m. spectrum around the centre frequency produced by a sinusoidal drive signal is displayed using a measurement bandwidth around 1 % of the deviation to be measured. The peak-to-peak deviation can be read immediate
49、ly as indicated in Figure 2. In case the deviation meter or spectrum analyzer is not able to measure properly when the carrier is modulated by the main bit stream, it may be necessary to carry out the measurement in the absence of modulation. 2.2.3 Presentation of results Input signal level and frequency, together with the measured deviation and the calculated deviation sensitivity, are tabulated. 2.2.4 Details to be specified The following items should be included, as required, in the detailed equipment specifica