1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T Q.400-Q.490TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (11/1988) SERIES Q: SWITCHING AND SIGNALLING Specifications of Signalling System R2 ITU-T Recommendations Q.400-Q.490 (Formerly CCITT Recommendations) ITU-T Q-SERIES RECOMMENDATIONS SWITCHING AND
2、SIGNALLING SIGNALLING IN THE INTERNATIONAL MANUAL SERVICE Q.1Q.3 INTERNATIONAL AUTOMATIC AND SEMI-AUTOMATIC WORKING Q.4Q.59 Basic Recommendations Q.4Q.9 Numbering plan and dialling procedures in the international service Q.10Q.11 Routing plan for international service Q.12Q.19 General Recommendation
3、s relative to signalling and switching systems (national or international) Q.20Q.34 Tones for use in national signalling systems Q.35Q.39 General characteristics for international telephone connections and circuits Q.40Q.47 Signalling for satellite systems Q.48Q.49 Signalling for circuit multiplicat
4、ion equipment Q.50Q.59 FUNCTIONS AND INFORMATION FLOWS FOR SERVICES IN THE ISDN Q.60Q.99 Methodology Q.60Q.67 Basic services Q.68Q.79 Supplementary services Q.80Q.99 CLAUSES APPLICABLE TO ITU-T STANDARD SYSTEMS Q.100Q.119 General clauses Q.100Q.109 Transmission clauses for signalling Q.110Q.114 Cont
5、rol of echo suppressors Q.115 Abnormal conditions Q.116Q.119 SPECIFICATIONS OF SIGNALLING SYSTEMS No. 4 AND No. 5 Q.120Q.249 Specifications of Signalling System No. 4 Q.120Q.139 Specifications of Signalling System No. 5 Q.140Q.179 SPECIFICATIONS OF SIGNALLING SYSTEM No. 6 Q.250Q.309 SPECIFICATIONS O
6、F SIGNALLING SYSTEM R1 Q.310Q.399 SPECIFICATIONS OF SIGNALLING SYSTEM R2 Q.400Q.499 DIGITAL EXCHANGES Q.500Q.599 INTERWORKING OF SIGNALLING SYSTEMS Q.600Q.699 General considerations Q.600Q.609 Logic procedures Q.610Q.697 Interworking of Signalling Systems No. 7 and No. 6 Q.698 Interworking between D
7、igital Subscriber Signalling System No. 1 and Signalling System No. 7 Q.699 SPECIFICATIONS OF SIGNALLING SYSTEM No. 7 Q.700Q.799 Q3 INTERFACE Q.800Q.849 DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1 Q.850Q.999 PUBLIC LAND MOBILE NETWORK Q.1000Q.1099 INTERWORKING WITH SATELLITE MOBILE SYSTEMS Q.1100Q.11
8、99 INTELLIGENT NETWORK Q.1200Q.1699 SIGNALLING REQUIREMENTS AND PROTOCOLS FOR IMT-2000 Q.1700Q.1799 SPECIFICATIONS OF SIGNALLING RELATED TO BEARER INDEPENDENT CALL CONTROL (BICC) Q.1900Q.1999 BROADBAND ISDN Q.2000Q.2999 For further details, please refer to the list of ITU-T Recommendations. Signalli
9、ng System R2 (1988) i ITU-T Recommendations Q.400-Q.490 Specifications of Signalling System R2 Summary Signalling System R2 is used as an international signalling system within international regions. Suitable for both automatic and semi-automatic working, it provides sufficient signals in both direc
10、tions to permit the transmission of numerical and other information relating to the called and calling subscribers lines and to increase routing facilities. System R2 is specified for one-way operation on analogue and digital transmission systems and for both-way operation on digital transmission sy
11、stems. Distinction is made between line signalling (supervisory signals) and interregister signalling (call set-up control signals). Versions of line signalling are specified for use on 4-wire carrier or PCM circuits. Nevertheless, the interregister signalling specified can also be used on 2-wire ci
12、rcuits. The interregister signalling is a compelled multifrequency code system which offers the possibility of end-to-end signalling. Source ITU-T Recommendations Q.400-490 were prepared by CCITT Study Group XI (1985-1988) and approved by WTSC in Melbourne on 25 November 1988. Those texts were origi
13、nally published in Blue Book, Fascicle VI.4. ii Signalling System R2 (1988) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-
14、T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for st
15、udy by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSC Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a
16、 collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or
17、implementation of this Recommendations may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development p
18、rocess. As of the date of approval of this Recommendations, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendations. However, implementors are cautioned that this may not represent the latest information and are therefore st
19、rongly urged to consult the TSB patent database. ITU 2002 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from ITU. Signalling System R2 (1988) ii
20、i CONTENTS Specifications of Signalling System R2 Rec. No. Page INTRODUCTION General . 1 SECTION 1 Definitions and functions of signals Q.400 1.1 Forward line signals 5 1.2 Backward line signals . 5 1.3 Forward register signals 6 1.4 Backward register signals . 7 SECTION 2 Line signalling, analogue
21、version Q.411 2.1 Line signalling code 9 Q.412 2.2 Clauses for exchange line signalling equipment. 10 2.3 Clauses for transmission line signalling equipmenet 16 Q.414 2.3.1 Signal sender. 16 Q.415 2.3.2 Signal receiver 18 Q.416 2.4 Interruption control. 20 SECTION 3 Line signalling, digital version
22、Q.421 3.1 digital line signalling code 25 Q.422 3.2 clauses for exchange line signalling equipment 26 Q.424 3.3 protection against the effects of faulty transmission. 31 Q.430 3.5 conversion between analogue and digital versions of system R2 line signalling 32 SECTION 4 Interregister signalling Q.44
23、0 4.1 General 53 Q.441 4.2 Signalling code . 56 Q.442 4.3 Pulse transmission of backward signals A-3, A-4, A-6 or A-15. 66 4.4 Multifrequency signalling equipment . 67 Q.450 4.4.1 General 67 Q.451 4.4.2 Definitions 68 Q.452 4.4.3 Requirements relating to transmission conditions 70 Q.454 4.4.4 The se
24、nding part of the multifrequency signalling equipment 71 Q.455 4.4.5 The receiving part of the multifrequency equipment 72 4.5 Range, speed and reliability of interregister signalling. 75 Q.457 4.5.1 Range of interregister signalling. 75 Q.458 4.5.3 Reliability of interregister signalling 79 Annexes
25、 to Section 4: Annex A Development of formulae for the power level of signalling frequencies. 80 Annex B Possible method of improving protection from interruptions 81 Annex C Development of a formula for the admissible forward transmission loss in a country of destination 82 iv Signalling System R2
26、(1988) Rec. N.oPage SECTION 5 Signalling procedures Q.460 5.1 Normal call set-up procedures for international working . 83 Q.462 5.1.2 Signalling between the outgoing international R2 register and an incoming R2 register in an international exchange. 84 Q.463 5.1.3 Signalling between the outgoing in
27、ternational R2 register and an incoming R2 register in a national exchange in the destination country. 86 Q.464 5.1.4 Signalling between the outgoing international R2 register and the last incoming R2 register 87 Q.465 5.1.5 Particular cases . 88 Q.466 5.1.6 Supervision and release of the call 88 Q.
28、468 5.2 Rounting and numbering for international working 89 5.3 Termination of interregister signalling . 89 Q.470 5.3.1 At an incoming R2 register situated in a transit exchange 89 Q.471 5.3.2 At the last incoming R2 register situated in the exchange to which the called subscriber is connected. 90
29、Q.472 5.3.3 At the last incoming R2 register situated in a transit exchange 92 Q.473 5.3.4 Use of end-of-pulsing signal I-15 in international working 93 Q.474 5.3.5 Use of group B signals 94 Q.475 5.4 Normal Release of outgoing and incoming R2 registers. 95 Q.476 5.5 Abnormal release of outgoing and
30、 incoming R2 registers. 97 Q.478 5.6 Relay and regeneration of R2 interregister signals by an outgoing R2 register in a transit exchange . 98 Q.479 5.7 Echo-suppressor control signalling requirements 100 Q.480 5.8 Miscellaneous procedures. 104 SECTION 6 Testing and maintenance Q.490 Testing and main
31、tenance 106 Annex A to Signalling System R2 Specifications Provision of a forward-transfer signalling facility . 110 Signalling System R2 (1988) 1 SPECIFICATIONS OF SIGNALLING SYSTEM R2 INTRODUCTION General Signalling System R2 is used as an international signalling system within international regio
32、ns (world numbering zones). Moreover, System R2 can be used for integrated international/national signalling if it is employed, in conformity with the present specifications, as a signalling system in the national networks of the region concerned. Suitable for both automatic and semi-automatic worki
33、ng it offers a high reliability in transmission of the information necessary for setting up a call. It allows for rapid call set-up and provides sufficient signals in both directions to permit the transmission of numerical and other information relating to the called and calling subscribers lines an
34、d to increase routing facilities. System R2 is specified for one-way operation on analogue and digital transmission systems and for both-way operation on digital transmission systems. Distinction is made between line signalling (supervisory signals) and interregister signalling (call set-up control
35、signals). Versions of line signalling are specified for use on 4-wire carrier or PCM circuits. Nevertheless, the interregister signalling specified can also be used on 2-wire circuits. System R2 is suitable for use on satellite links and 3 kHz spaced carrier circuits. It is not designed for use on t
36、ransmission systems with speech interpolation but it may be used on digital transmission systems with speech interpolation as long as transparency for pulsed interregister signals is guaranteed. The interregister signalling is a compelled multifrequency code system. This offers the possibility of en
37、d-to-end signalling and to take advantage of modern switching systems by providing a sufficient number of signals in both directions. System R2 is capable of normal interworking with other CCITT signalling systems. Line signalling The following versions of line signalling are specified: line signall
38、ing for carrier systems called the analogue version; line signalling for PCM systems called the digital version. Since multifrequency signalling permits exchange of a large amount of information between registers, the quantity of information that has to be transmitted in the form of line signals is
39、small. The versions of line signalling for System R2 have been designed accordingly. The analogue line signalling version standardized originally for use on international circuits is also suitable for national working. An analogue (in-band) line signalling version is only described for the specific
40、use on 3 kHz spaced carrier circuits of international submarine cables. The analogue version is link-by-link using an out-band, low-level continuous tone-on-idle signalling method. Signal transfer simply involves the transition from one signalling condition to the other, except for the clearing sequ
41、ence which is based on additional timing criteria. It is necessary to have a device for protection against the effect of interruption in the signalling channel since interruption of the signalling frequency simulates a false seizure or answer signal (interruption control). The signalling frequency i
42、s transmitted at a low level which avoids overloading of the transmission system when the frequency is sent continuously in both directions on all circuits in the idle state. The digital version is link-by-link using two signalling channels in each direction of transmission per speech circuit. The s
43、ignalling channels are two of the four provided for channel associated signalling in a 2048 kbit/s primary multiplex (see Recommendation G.732). Protection against the effects of faulty transmission is provided. 2 Signalling System R2 (1988) The analogue version and the digital version of the line s
44、ignalling can be converted to each other by a transmultiplexer or other conversion equipment. Such equipment forms a conversion point between analogue (FDM) transmission on one hand and digital (PCM) transmission on the other hand. The System R2 line signalling, however, must be treated separately b
45、ecause for both transmission systems different line signalling versions are specified. Although both versions are described in some detail, a description of the actual conversion is given in Recommen-dation Q.430. Although these versions do not include a forward-transfer signal, forward-transfer sig
46、nalling may be introduced for international working by bilateral agreement. Interregister signalling The interregister signalling is performed end-to-end using a 2-out-of-6 in-band multifrequency code with forward and backward compelled signalling. The signalling frequencies do not therefore overlap
47、 with the line signalling frequency and differ according to the direction of transmission with a view to possible use of the multifrequency part of the system on 2-wire circuits. System R2 is designed to use six signalling frequencies (1380, 1500, 1620, 1740, 1860 and 1980 Hz) in the forward directi
48、on and six signalling frequencies (1140, 1020, 900, 780, 660 and 540 Hz) in the backward direction. Nevertheless for national application less signalling frequencies may be used. End-to-end signalling is a method for signalling between registers over two or more links in tandem without signal regene
49、ration in intermediate exchanges (see Figure 1). T0209420-02OutgoingR2 registerIncoming R2register in atransit exchangeIncoming R2register in atransit exchangeIncoming R2register in aninternational ornational terminalexchangeFIGURE 1 Principle of end-to-end R2 interregister signalling With this signalling method, in general only the address information needed for routing the call through an intermediate (transit) exchange is transferred from the outgoing register to the incoming register. In the inte
