BS-EN-60835-2-10-1993 BS-7573-2.10-1993 IEC-60835-2-10-1992.pdf

BRITISH STANDARD BS EN 60835-2-10: 1993 BS 7573-2.10: 1993 IEC 835-2-10: 1992 Methods of measurement for equipment used in digital microwave radio transmission systems Part 2: Measurements on terrestrial radio-relay systems Section 2.10 Overall system performance The European Standard EN 60835-2-10:1993 has the status of a British Standard UDC 621.396.7:621.317.083 Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 09:23:23 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 60835-2-10:1993 This British Standard, having been prepared under the direction of the Electronic Equipment Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 15 June 1993 © BSI 01-2000 The following BSI references relate to the work on this standard: Committee reference EEL/25 Draft for comment 91/29838 DC ISBN 0 580 21854 6 Cooperating organizations The European Committee for Electrotechnical Standardization (CENELEC), under whose supervision this European Standard was prepared, comprises the national committees of the following countries: AustriaItaly BelgiumLuxembourg DenmarkNetherlands FinlandNorway FrancePortugal GermanySpain GreeceSweden IcelandSwitzerland IrelandUnited Kingdom Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 09:23:23 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 60835-2-10:1993 © BSI 01-2000i Contents Page Cooperating organizationsInside front cover National forewordii Foreword2 Introduction3 1Scope3 2Normative references3 3Bit-error ratio (BER)3 4Jitter5 5Acceptable input interruption5 6Verification of protection switching operation5 Annex ZA (normative) Other international publications quoted in this standard with the references of the relevant European publications8 National annex NA (informative) Committees responsibleInside back cover National annex NB (informative) Cross-referenceInside back cover Figure 1 Illustration of interference sources in three-channel radio-relay system6 Figure 2 Presentation of carrier-to-noise ratio degradation by two bit-error ratio (BER) functions6 Figure 3 Effect of co-channel interference and adjacent-channel interference7 Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 09:23:23 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 60835-2-10:1993 ii © BSI 01-2000 National foreword This British Standard has been prepared under the direction of the Electronic Equipment Standards Policy Committee and is the English language version of EN 60835-2-10:1993 Methods of measurement for equipment used in digital microwave radio transmission systems Part 2: Measurements on terrestrial radio-relay systems: Section 10 Overall system performance, published by the European Committee for Electrotechnical Standardization (CENELEC). It is identical with IEC 835-2-10:1992 published by the International Electrotechnical Commission (IEC). BS EN 60835 is published in three Parts. The other Parts are: 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. Copies of International Radio Consultative Committee (CCIR) documents may be purchased through BSI Sales, Linford Wood, Milton Keynes, MK14 6LE. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards 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 8, an inside back cover and a 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. Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 09:23:23 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN 60835-2-10 January 1993 UDC 621.396.7:621.317.083 Descriptors: Radiocommunications, radio equipment, microwave frequencies, digital transmission, radio-relay systems, measurement English version Methods of measurement for equipment used in digital microwave radio transmission systems Part 2: Measurements on terrestrial radio-relay systems Section ten Overall system performance (IEC 835-2-10:1992) Méthodes de mesure applicables au matériel utilisé pour les systèmes de transmission numérique en hyperfréquence Partie 2: Mesures applicables aux faisceaux hertziens terrestres Section dix Performance globale du systéme (CEI 835-2-10:1992) Meßverfahren für Geräte in digitalen Mikrowellen-Funkübertragungssystemen Teil 2: Messungen an terrestrischen Richtfunksystemen Hauptabschnitt zehn Leistungsdaten des Gesamtsystems (IEC 835-2-10:1992) This European Standard was approved by CENELEC on 1992-06-16. 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 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 language 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, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels © 1993 Copyright reserved to CENELEC members Ref. No. EN 60835-2-10:1993 E Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 09:23:23 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 60835-2-10:1993 © BSI 01-2000 2 Foreword The text of document 12E(C0)145, as prepared by sub-committee 12E, Radio relay and fixed satellite communications systems, of IEC technical committee 12, Radiocommunications, was submitted to the IEC-CENELEC parallel vote in August 1991. The reference document was approved by CENELEC as EN 60835-2-10 on 16 June 1992. The following dates were fixed: Annexes designated “normative” are part of the body of the standard. In this standard, Annex ZA is normative. latest date of publication of an identical national standard(dop) 1993-12-01 latest date of withdrawal of conflicting national standards(dow) 1993-12-01 Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 09:23:23 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 60835-2-10:1993 © BSI 01-20003 Introduction In previous sections of IEC 835-2 measurement methods for parameters of the digital radio-relay system have been discussed separately for each part of the system. In addition to these tests, the overall performance of a complete simulated system should be tested. The tests cover the two basic parameters of digital transmission systems, bit-error ratio and jitter, as well as the acceptable input interruption and verification of the protection switching operation, which are all affected by the presence of more than one radio channel and/or radio hop. The measurement of other additional parameters such as error-free seconds, burst-error ratio, block-error ratio, which remain under consideration by other international organizations, may also be required. 1 Scope This section IEC 835-2 deals with measurements to be carried out during factory acceptance tests and type approval tests on a complete simulated digital radio-relay system, following tests on the individual parts of the system. In the following, it will be stated for each parameter whether or not a multi-hop measurement is required in the overall system performance test, depending on the cumulative or non-cumulative property of that parameter. In this section, the emphasis is on the system configuration. For methods of measurement, see under the appropriate future sections of IEC 835-1 and IEC 835-2. 2 Normative references The following standards 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 standards are subject to revision, and parties to agreements based on this section of IEC 835-2 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. 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 satellite earth stations Section 4: Transmission performance. IEC 835-2-4, 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. (In preparation) IEC 835-2-6, Methods of measurement for equipment used in digital microwave radio transmission systems Part 2: Measurements on terrestrial radio-relay systems Section 6: Protective switching. (Under consideration) IEC 835-2-8, Methods of measurement for equipment used in digital microwave radio transmission systems Part 2: Measurements on terrestrial radio-relay systems Section 8: Adaptive equaliser. (In preparation) CCIR Report 930-2, Performance objectives for digital radio-relay systems Recommendations and reports of the CCIR, 1990, Annex to Volume IX Part 1. 3 Bit-error ratio (BER) The method of measurement is given in IEC 835-1-4. The configuration of the transmit-receive section during the measurement is discussed in the future IEC 835-2-4. As explained in IEC 835-2-4, the bit-error ratio of a transmit-receive section has a receiver input level dependent part and a constant part covering the nominal receiver input level. These two parts should be distinguished in overall system performance tests. In addition to single-hop measurements over individual channels, the bit-error ratio degradation due to multi-channel and multi-hop transmission should also be measured where applicable. 3.1 Bit-error ratio versus receiver input level In a multi-hop link, this test is carried out separately for each hop for every radio channel, including tests with greater than nominal receiver input levels to cover up-fade conditions. There is no need for the measurement of the complete multi-hop link as there is no degradation due to multi-hop transmission (assuming that reduced receiver input level due to flat fading is present only in a single hop at a time). Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 11 09:23:23 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 60835-2-10:1993 4 © BSI 01-2000 3.2 Residual bit-error ratio at nominal receiver input level This is the low bit-error ratio which is due to low-level residual noise sources and equipment degradation, including ageing, in the transmit-receive equipment of each hop (see CCIR Report 930-2). The contribution of each hop is cumulative so it is measured for the complete multi-hop link in all radio channels. The definition and method of measurement of the residual bit-error ratio is described in IEC 835-1-4. 3.3 Bit-error ratio degradation due to multi-channel interference 3.3.1 Definition and general consideration Multi-channel interference is one of the important parameters of multi-channel microwave transmission systems as it is closely related to efficient spectrum utilization. It is mainly determined by the radio-frequency channel arrangement, the frequency response of the individual radio channels, the cross-polarization discrimination of the antenna system and the transmission medium during fading conditions, by multipath propagation. Multi-channel interference sources are illustrated in Figure 1, showing two kinds of interference. a) Adjacent-channel interference, originating from neighbouring channels, generated by the unwanted reception of signals transmitted either in the same direction by neighbouring stations (far-end interference) or in the opposite direction by the same station (near-end interference). The former is due to insufficient selectivity of the channel filters whilst the latter is mainly caused by insufficient de-coupling between transmitter and receiver (e.g. in the circulator and/or polarizer). b) Co-channel interference, originating from the same channel, generated either by the unwanted reception of signals transmitted by neighbouring stations via rearwards antenna radiation in the opposite direction, or by the unwanted reception of cross-polarized signals due to finite cross-polarization discrimination. All types of multi-channel interference result in the degradation of the bit-error ratio. Such degradation can also be related to the carrier-to-noise ratio. It can be quantified by the difference in decibels between the r.f. carrier levels at the receiver input, measured with and without interfering channels, that result in the same specified bit-error ratio. 3.3.2 Method of measurement The carrier-to-noise ratio degradation of a radio channel in a multi-channel transmission system is measured on a single transmit-receive section, as explained in IEC 835-2-4, with all radio channels working under operational conditions. The radio channel under test is connected to a bit-error ratio measuring instrument as explained in IEC 835-1-4. The digital inputs of all interfering channels are driven by independent (uncorrelated) pseudo-random bit sequence (p.r.b.s.) generators. All interfering channels are first switched off, and the r.f. input level of the test channel is adjusted for a specified bit-error ratio (e.g. 105). The interfering channels are then switched on, resulting in an increase of the test channel bit-error ratio. The test channel r.f. input level is subsequently increased until the above specified bit-error ratio is restored, and the difference in decibels between the two carrier levels is noted. 3.3.3 Presentation of results Results are presented by stating the value in decibels of the carrier-to-noise ratio degradation pertaining to a specified bit-error ratio. Alternatively, two curves may be presented, with and without interference, both showing the bit-error ratio as a function of the carrier-to-noise ratio (see Figure 2). 3.